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Teachers recommend solving Kerala Syllabus Plus One Botany Previous Year Question Papers and Answers Pdf Board Model Paper 2021 to improve time management during exams.

Kerala Plus One Botany Board Model Paper 2021 with Answers

I. Answer any 3 questions from 1 to 6. Each carries 1 scroes. (3 × 1 = 3)

Question 1.
Fill imthe blank :
Network of hyphae in fungi is called .
Answer:
Mycelium

Question 2.
Name the plant hormone known as ‘Stress hormone’,
Answer:
Abscissic acid (ABA)

Question 3.
Choose the correct Answer from the bracket: AIDS in human being is caused by ______.
(a) Bacterium
(b) Fungus
(c) Virus
(d) Mycoplasma
Answer:
c) Virus

Question 4.
Fill in the blank:
Exchange of genetic materials between homologous chromosomes during Pachytene stage of Meiosis-I is called.
Answer:
Crossing over

Question 5.
Name the Pigment that gives pink colour to root nodules of Leguminous plants.
Answer:
Leghaemoglobin

Question 6.
Fill in the blank :
In Rhizophora certain roots grow vertically for breathing. Such roots are called ____ .
Answer:
Pneumatophores

II. Answer any 9 questions from 7 to 24. Each carries 2 scores. (9 × 2 = 18)

Question 7.
Complete the table with appropriate terms:
Classes
Chlorophyceae
(c)
Rhodophyceae

Common Name
(a)
Brown algae
Red algae

Major Pigments
Chlorophyll a,b
Chlorophyll a, c Fucoxanthin
Chlorophyll a, d (d)

Stored Food
(b)
Manitol Laminarin
Floredean starch
Answer:
(a) Green algae
(b) Starch
(c) Phaeophyceae
(d) Phycoerythrin

Question 8.
Write any two anatomical differences between stem and Root of Angiosperms.
Answer:
Stem
(a) Xylem is endarch
(b) Trichome is present Root
(a) Xylem is exarch
(b) Root hair is present

Question 9.
Write the difference between spring wood and autumn wood.
Answer:

1. Spring wood
   • Cambium is more active
   • Large quantity of xylem vessels are formed.
2. Autumn wood
   • Cambium is less active
   • Fewer quantity of xylem vessels are formed.

Question 10.
(a) Which plants are known as ‘Amphibians of the plant kingdom’ ?
(b) Give reason.
Answer:
a) Bryophytes
b) They are found in moist, cool and shaded localities and they require water for sexual reproduction.

Question 11.
Xylem is a conducting tissue seen in higher plants. Write the names of four elements of Xylem.
Answer:

1. Trachieds
2. Vessels
3. Xylem fibre
4. Xylem parenchyma

Question 12.
Phyllotaxy is the pattern of arrangement of leaves on stem of branch. Write the name of any two types of Phyllotaxy.
Answer:

1. Alternate phyllotaxy
2. Opposite phyllotaxy

Question 13.
(a) What is the name of the model of Plasma membrane proposed by Singer and Nicolson.
(b) Write any one function of Plasma membrane.
Answer:
a) Fluid mosaic model
b) It helps in the transport of solvent molecules.

Question 14.
(a) Define imbibition.
(b) Write one benefit of imbibition to plants.
Answer:
a) It is a kind of diffusion in which certain hydrophilic colloid molecules absorb water without forming solution.
b) It helps in the germination of seeds.

Question 15.
(a) Write the name of the stage of Mitosis in the given figure.
(b) Write one main event occurring in this stage.

Answer:
a) Anaphase
b) Chromosome move towards opposite poles of the cell

Question 16.
Write any two purposes of transpiration.
Answer:

1. It provides cooling effect
2. It helps in the absorption of water and Minerals.

Question 17.
Write any two differences between Cyclic and Non – cyclic photophosphorylation.
Answer:

Question 18.
(a) Identify and write the name of cell organelle given in the figure.
(b) Label the parts marked as A, B.

Answer:
a) Mitochondria
b) A – Matrix
B – Cristae

Question 19.
(a) Write the name of two phases of Photosynthesis.
Answer:
a) Light reaction and Dark reaction
b) Light reaction occur in Grana
Dark reaction occur in Stroma

Question 20.
(a) Write the name of the growth curve seen in the given figure.
(b) Write the name of phases marked as A and B.

Answer:
a) Sigmoid curve
b) A – Lag phase
B – Stationary phase

Question 21.
Match the following :

(b) Which are the sites of these phases in chloroplast ?
Answer:
Lysosome – Store hydrolytic enzymes
Golgi apparatus – Packaging of materials
Endoplasmic reticulum – Lipid synthesis
Vacoules – Store excretory products

Question 22.
(a) What is fermentation?
(b) Which are the main products produced as a result of fermentation in (i) Yeast, (ii) Muscles?
Answer:
a) It is the anaerobic respiration that takes place in the presence of micro organism and give products.
b) Yeast – Ethyl alcohol and C02 Muscle – Lactic acid

Question 23.
Observe the figure of Calvin cycle given below:
(a) Write the name of three major events marked as A, B and C.
(b) Find out the name of first C02 acceptor given in the figure.

Answer:
a) A – Carboxylation
B – Reduction
C – Regeneration
b) RuBP

Question 24.
(a) What is ‘Kranz’ anatomy ?
(b) Write two examples of plants that exhibit ‘Kranz’ anatomy.
Answer:
a) In C₄ plants bundle sheath chloroplast are centripetally in arranged ring shape such a leaf anatomy is called Kranz anaotmy.
b) Sugarcane, Maize

III. Answer any 3 questions from 25 to 30. Each carries 3 scores. (3 ×3 = 9)

Question 25.
Flowers are classified into three types based on the position of floral parts on thalamus.
(a) Which are they ?
(b) Write the position of ovary in each one of them.
Answer:
a) Hypogynous
Perigynous
Epigynous

b) Hypogynous – ovary Superior Perigynous – ovary half inferior Epigynous – ovary inferior

Question 26.
(a) What is Respiratory Quotient (RQ)?
(b) Write the RQ of (i) Carbohydrate, (ii) Fat.
Answer:
a) It is the ratio of volume of C02 evolved to the volumeof oxygen consumed,
b) i) Carbohydrate 1 ii) Fat 0.7

Question 27.
The essentiality of an element to plants is determined by three criteria. Which are they?
(b) Write the site of this process in cell.
(c) Write the name of the end product of this process.
Answer:

1. It supports normal growth and reproduction.
2. Role of element must be specific.
3. Element is directly involved in metabolism.

Question 28.
(a) Name the process which is common for Aerobic and Anaerobic respiration.
(a) Write the name of plant hormone responsible for ripening of fruits.
(b) Write any two other functions of this hormone.
Answer:
a) Glycolysis
b) Cytoplasm
c) two molecules of Pyruvic acid

Question 29.
Observe the given figure of cell cycle
(a) Write the name of phases marked as A and BN A, B
(b) Write one important event in A and B.

Answer:
a) A – S phase
B – G2 phase

b) i) In S phase DNA replication occurs
ii) In G2 phase RNA and protein are produced and cell growth continues

Question 30.
(a) Write the name of plant hormone responsible for ripening of fruits.
(b) Write any two other functions of this hormone.
Answer:
a) Ethylene

b) It promote the production of female fowers in cucumbers. It promotes internodal elongation in deep water rice plants.

Teachers recommend solving Kerala Syllabus Plus One Botany Previous Year Question Papers and Answers Pdf Board Model Paper 2022 to improve time management during exams.

Kerala Plus One Botany Board Model Paper 2022 with Answers

Answer any three questions from 1 to 4. Each carries 1 score. (3 × 1 = 3)

Question 1.
Fill in the blank.
Reserve food of rhodophyceae is ____
Answer:
Floridean starch

Question 2.
Choose the correct answer.
Water loss in its liquid phase from the tip of grass blades is
(a) Guttation
(b) Osmosis
(c) Transpiration
(d) lmbibition
Answer:
A) Guttation

Question 3.
Name the special type of anatomy present in C₄ plants.
Answer:
Kranz anatomy

Question 4.
Fill in the blank.
The process of breakdown of glucose to pyruvic acid is called
Answer:
Glycolysis

II. Answer any 9 questions from 5 to 17. Each carries 2 scores. (9 × 2 = 18)

Question 5.
Write any two factors for seed dormancy.
Answer:

1. Impermeable and hard seed coat
2. Immature embryo

Question 6.
List out any four external factors affecting photo-synthesis.
Answer:
Light, CO₂ concentration, Temperature, Water.

Question 7.
Explain the significance of mitosis.
Answer:

1. It results in the production of diploid daughter cells with identical genetic constitution.
2. The growth of multicellular organisms.

Question 8.
What is measosome? Mention any two functions of mesosome.
Answer:
(a) Mesosomes are special membranous structure of bacteria which is formed by the extension of plasma membrane in to the cell.

1. They help in cell wall formation.
2. DNA replication and distribution to daughter cells.

Question 9.
Observe the figure of citric acid cycle given below. Identify (a), (b), (c) and (d) in the figure.

Answer:
A – citric acid,
B – alpha ketoglutaric acid,
C – succinic acid,
D – oxaloacetic acid

Question 10.
Name the four different compnents of phloem in angiosperms.
Answer:

1. Sieve tube
2. Companion cell
3. Phloem paraenchyma
4. Pholem fibre

Question 11.
Observe the figure of cell cycle given below.
a) Name the two phases of cell cycle.
b) Identify the stages (a) and (b) of the cell cycle.

Answer:
a) Interphase and M phase
b) (a) G1 phase,
(b) G2 phase

Question 12.
Differentiate Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER).
Answer:
RER – Rough endoplasmic reticulum with ribosomes on their surface. It is Involved in protein synthesis and secretion.
SER – Smooth endoplasmic reticulum devoid of ribosomes on their surface. It is involved in lipid synthesis.

Question 13.
What are bulli forms cells? Mention their function.
Answer:
In grasses, certain adaxial epidermal cells are large,empty,colourless cells.These are called bulliform cells. Due to water stress, they make the leaves curl inwards to minimise water loss.

Question 14.
Observe the figure and label the parts (a), (b) and (c). Write down the functions of root hairs.

Answer:
a) Region of Maturation
b) Region of Elongation
c) Region of Meristematic
Function – Absorption of water and minerals

Question 15.
Match the following.

Answer:

Question 16.
Define diatomaceous earth. Mention anyone use of diatomaceous earth.
Answer:
Dead remains of diatoms are known as ‘diatomaceous earth’. Used in polishing and filtration of oils and syrups.

Question 17.
Observe the figure and identify (1) and (2)

Answer:

1. Antiport
2. Symport

Answer any 3 questions from 18 to 22. Each carried 2 scores. (3 × 3 = 9)

Question 18.
Define phyllotaxy. Explain any two types of phyllotaxy.
Answer:
It is the mode of arrangement of leaves on the stem or branch.

1. Alternate – A single leaf at each node
2. Opposite – A pair of leaves at each node

Question 19.
Expalin the differnt steps involved in the formation of a root nodule in leguminous plants.
Answer:
(a) Rhizobium attaches root hair,
(b) Root hair curls
(c) Infected thread carries the bacteria to the inner cortex.
(d) The bacteria get modified into rod-shaped bacteroids and cause inner cortical and pericycle cells to divide.
(e) A mature nodule is complete with vascular tissues continuous with those of the root.

Question 20.
Give any three differences between aerobic respiration and fermentation.
Answer:

Question 21.
The functions of different Plant Growth Regulators (PGR) are given.
Arrange them into respective columns.
• apical dominance
• bolting
• delay leaf senescence
• rooting of stem cutting
• overcome apical dominance

Answer:

Question 22.
Observe the given diagram of LHC

a) Name the pigmenf that forms the reaction center.
b) Name any one accessory pigment involved in photosynthesis.
c) Mention the function of accessory pigment.
Answer:
a) Chlorophyll a

b) Chlorophyll b’or: Xanthophylls

c) • Absorb light and transfer the energy to chlorophyll a.
• It helps to protect chlorophyll a form photo oxidation.

Teachers recommend solving Kerala Syllabus Plus One Botany Previous Year Question Papers and Answers Pdf Board Model Paper 2023 to improve time management during exams.

Kerala Plus One Botany Board Model Paper 2023 with Answers

I. Answer any three questions from 1-5. Each carries 1 score. (3 × 1 = 3)

Question 1.
Observe the relationship between the first two terms and fill in the blank.
Mushroom : Agaricus
Bread mould : ________
Answer:
Rhizopus

Question 2.
All the tissues on the inner side of endodermis together constitute ______
Answer:
Stele

Question 3.
Complete oxidation of organic substance in the presence of oxygen is ______
Answer:
Aerobic respiration

Question 4.
Observe the figure given below. It shows two phases in the life cycle of Funaria. Identify and write the phase marked as ‘A’.

Answer:
Sporophytic stage

Question 5.
Name the enzyme present in plants which shows carboxylation and oxygenation activity.
Answer:
RuBisCO

II. Answer any 9 questions from 6-16. Each carries 2 scores. (9 × 2 = 18)

Question 6.
Diatoms, the chief producers in the ocean are useful in many ways. Evaluate the statement.
Answer:
Cell wall remains of diatoms in ocean floor is called Diatomaceous earth if is used in polishing, filtration of oils and syrups.

Question 7.
An important model of the structure of plasma membrance was proposed by Singer and Nicolson.
(a) What is this model called?
(b) Which component forms bilayer?
(c) Identify and write the two types of proteins present in plasma membrane.
Answer:
(a) Fluid mosaic model.
(b) Phospholipids.
(c) Integral protein and peripheral protein

Question 8.
Observe the following phases of nuclear divisions during mitosis and answer the following questions.

(a) Name the two phase ‘A’ and ‘B’
(b) What are the main events occurring in ‘A’ phase?
Answer:
(a) A- Anaphase.
B – Telophase.

(b) • Centromeres split and chromatids separate.
• Chromatids move to opposite poles of the cell

Question 9.
Give the scientific term for the following.
(a) Pairing of homologous chromosomes.
(b) Echange of genetic material between two homologous chromosomes.
Answer:
(a) Synapsis.
(b) Crossing over.

Question 10.
Match the following:

Answer:

Question 11.
Rough Endoplasmic Reticulum (RER) and Smooth endoplasmic Reticulum (SER) are morphologically and functionally different. Justify this statement.
Answer:

Question 12.
Observe the given graph. The graph represents the phases of growth.

(a) Name the growth curve.
(b) Name the different phases of growth represented as (a), (b) and (c).
Answer:
a) Geometrical growth curve
b) (a) Lag phase.
(b) Log or.exponential phase.
(c) Stationary phase

Question 13.
Fermentation is the incomplete oxidation of pyruvic acid. Find the difference between two types of fermentation in microorganisms.
Answer:

Question 14.
Observe the following diagram a, b, c, d identify the placentation.

Answer:
(a) Marginal placentation.
(b) Axile placentation.
(c) Parietal placentation.
(d) Free central placentation.

Question 15.
Choose the appropriate function from the bracket and fill the blank against each plant hormone in the table. (Ripening of fruits, Increase the length of stem in sugarcane, Induce parthenocarpy, Helps to overcome apical dominance)

Answer:

Question 16.
(a) Which is the special leaf anatomy seen in C₄ plants?
(b) Productivity and yield are better in C₄ plants than C₃ plants. Why?
Answer:
(a) Kranz anatomy
(b) They lack a process called photo-respiration.
They can fix CO₂ in low atmospheric CO₂ concentration.
They can tolerate higher temperature conditions

III. Answer any 3 questions from 17-20. Each carries 3 scores. (3 × 3 = 9)

Question 17.
The following are the anatomical features of flowering plants. Arrange these features in the table given below.
i) Exarch xylem
ii) Presence of hypodermis
iii) Palisade parenchyma
iv) Conjoint and open vascular bundle
v) Endodermis with casparian strips
vi) Large empty bulliform cells

Question 18.
Observe the figure ‘A’ and ‘B’ and answer the questions.
Img- 1
(a) Define venation.
(b) Name and explain the type of venation in ‘A’ and ‘B’.
Answer:
(a) The arrangement of veins and veinlet in the leaf lamina is called venation.

(b) A’ – Reticulate Venation: Vein and veinlet form a network on leaf lamina. eg. dicotyledonous plants.
‘B’- Parallel Venation: Vein and veinlet run parallel to each other on leaf lamina. eg. monocotytedonous plants.

Question 19.
Photophosphorylation takes place during photosynthesis.
(a) Name the two types of photophos-phorylations.
(b) Mention the differences between them.
Answer:
(a) Cyclic Photophosphorylation Non cyclic Photophosphorylation
(b)

Question 20.
Glycolysis is the partial oxidation of glucose to produce 2 molecules of pyruvic acid
(a) Where does glycolysis occur?
(b) Steps of glycolysis are given below. Write the name of compounds marked as (a), (b), (c) and (d).

Answer:
(a) Cytoplasm
(b) (a) Fructose-6-phosphate
(b) 3-phosphoglyceric acid
(c) Phosphoenolpyruvate
(d) Pyruvic acid

Teachers recommend solving Kerala Syllabus Plus One Botany Previous Year Question Papers and Answers Pdf March 2019 to improve time management during exams.

Kerala Plus One Botany Previous Year Question Paper March 2019

Answer all questions from question numbers 1 to 3. Each carry 1 score. (3 × 1 = 3)

Question 1.
Choose the Correct answer.
A structure seen in bacterial cell is _______
a) Nucleus
b) Lysosome
c) Plastid
d) Mesosome
Answer:
d) Mesosome

Question 2.
Observe the relationship between the first two terms and fill in the blank.
a) Mushroom : Agaricus
b) Bread mould :
Answer:
b) Rhizopus

Question 3.
Fill in the blank:
Cytokinesis in animal cell takes place by the ap-pearance of a in the plasma membrane.
Answer:
Cleavage furrow

Answer any nine questions from 4 to 14. Each carries two score. (9 × 2 = 18)

Question 4.
Observe the figure given below.

Identify the process demonstrated in the figure. Write the role of membrane in this process.
Answer:
Osmosis,
Active transport and passive transport occurs

Question 5.
Certain thylakoid pigments are called accessory pigments. Name them, Write their significance.
Answer:

1. Chlorophyll b, xanthophylls and carotene
2. Protect chlorophyll a molecule from photo-oxidation.

Question 6.
Notice the three simple tissues given below.
a) Sclerenchyma
b) Parenchyma
c) Collenchyma
Identify and write the tissue that consists of cells that are thickened at the corners. Write the function of this tissue.
Answer:
c) Collenchymas
• It provides mechanical support

Question 7.
Write any two differences between aerobic respira-tion and anaerobic respiration.
Answer:

1. Aerobic respiration takesplace in cytoplasm and mitochondria with the help of oxygen
2. Anaerobic respiration takesplace in cytoplasm without the use of oxygen

Question 8.
Observe the figure given below. It shows two phases in the life cycle of a plant.

Identify the phase marked as A. Write any two peculiarities of this state.
Answer:

1. A-sporophytic generation
2. It is diploid stage.it produces spores

Question 9.
Karyokinesis of mitosis is divided into fourstages. Name the second and third stage. Write any two features of second stage.
Answer:

1. 2nd metaphase, 3rd anaphase
2. Chromosomes are arranged at equator
3. Spindle fibres are attached to kinetochore of chromosomes

Question 10.
Observe the figure given below.

Identify the parts a, b. Write their functions.
Answer:
a) Grana
b) Stroma
• In grana light reaction takesplace and energy rich molecules are produced
• In sroma dark reaction takesplace and energy rich molecules are utilized

Question 11.
C₄ plants have a special leaf anatomy. Name that antomy. Write three peculiarities of this kind of anatomy.
Answer:

1. Kranz anatomy
2. Two types of chloroplast present
3. Bundle sheath chloroplast is large and agranal

Question 12.
Observe the figure given below.

Name the complex. Write its functions, go
Answer:

1. ATP synthase complex
2. It act as proton channel and oxidative phosphorylation takesplace.

Question 13.
Observe the elements given below.
Copper, Phosphorus, Boron, Magnesium, Potassium, Manganese, Chlorien Choose microelements from the above.
Answer:
Copper, boron, manganese and chlorine

Question 14.
Match the items of column A with B

Answer:

Answer any three questions from 15 to 18. Each carries three score. (3 × 3 = 9)

Question 15.
Write thee peculiarities of gynoecium seen in solanaceae and fabaceae.
Answer:

1. Solanaceae – bicarpellary, syncarpous and superior ovary with axile placentation
2. Fabaceae – monocarpellary, superior or half inferior ovary with marginal placentation

Question 16.
Plantgrowth regulators perform various functions in piant body.
a) Name the hormones responsible for apical dominance and bolting. Define the two phenomena.
b) Which plant hormone is referred to as an antagonist to gibberellic acid?
Answer:

1. Apical dominance-auxin Bolting-gibberellins
2. Apical dominance-Growth of apical bud inhibit the growth of lateral bud
3. Bolting-internodal elongation just prior to flowering

Question 17.
Name of three plants are given below.
a) Rhizophora eeognragnnoo
b) Bougainvillea aaiMaracnlnflgj
c) Pea oKoxd a.ajs1
Name the modifications seen in these plants. Write theirfunctions.
Answer:
a) Rhizophora-pneumatophore
• It helps in respiration

b) Bougainvillea-thorn
• It acts as defense structure

c) Pea-leaf tendril
• It helps in climbing

Question 18.
Observe the terms given below.
Xylem, Root hairs, Pith, Stomata, Cambium, Bulliform cells. From this, identify and write the structures seen in epidermal tissue system. Write their functions. (Hint: 3 structures)
Answer:

1. Root hair : absorption of water and minerals
2. Stomata : helps in gaseous exchange
3. Bulliform cells : it helps in rolling and unrolling of lamina.This help to reduce transpiration rate.

Teachers recommend solving Kerala Syllabus Plus One Botany Previous Year Question Papers and Answers Pdf March 2020 to improve time management during exams.

Kerala Plus One Botany Previous Year Question Paper March 2020

Part – A

I. Answer any 3 questions from 1 to 5. Each carries 1 score. (3 × 1 = 3)

Question 1.
Choose the correct answer. The organelle known as power house of the cell is :
a) Ribosome
b) Vacuole
Answer:
Mitochondria

Question 2.
Choose the correct answer
Caspanan strips are present in:
a) Dicot root
b) Dicot stem
c) Dicot leaf
d) Monocot stem
Answer:
Dicot root

Question 3.
Observe the figure given below. Name the Organism.

Answer:
Euglena

Question 4.
Observe the relationship between the first two terms and fill in the blank.
Metaphase : Spindle fibres attach to kinetochores.
_______ : Chromatids move to opposite poles
Answer:
Anaphase

Question 5.
Fill in the blank.
The number of carbon atoms in acetyl co-enzyme A, which take part in Kreb’s cycle is ______ .
Answer:
2

II. Answer any 9 questions from 6 to 16. Each carries 2 scores. (9 × 2 = 18)

Question 6.
Observe the figure given below:

a) Name the process.
b) Define the above identified process.
Answer:
a) Facilitated diffusion
b) In facilitated diffusion, special membrane proteins help the movement of substances across membranes without expenditure of ATP or energy

Question 7.
Analyse the table given below and fill in the blanks.

Answer:
a) Pairing of homologous chromosomes
b) Pachytene
c) Diplotene
d) Terminalisation of Chiasmata

Question 8.
Define hydroponics. Write one advantage of it.
Answer:
This technique of growing plants in a nutrient solution is known as hydroponlbs. In this method essential elements are used and their deficiency symptoms can be studied.

Question 9.
Peculiarities of certain cell organelles are given below:
a) Involved in protein synthesis.
b) Made up of many flat, disc shaped sacs or cisternae.
c) Bear ribosomes on their surface.
d) Rich in hydrolytic ensymes.
e) Membrane is absent

Copy the table given below and write the above pecularitie column.

Answer:

Question 10.
Analyse the table given below and fill in the blanks a, b, c, d

Answer:

Question 11.
The first step in respiration is glycolysis.
a) Define glycolysis.
b) Write the site of glycolysis.
Answer:
a) It is the Partial oxidation of glucose into 2 molecules of Pyruvic acid.
b) Cytoplasm

Question 12.
Observe the given figure showing C₄ pathway.
Atmospheric CO₂

a) Identify the cells A and B.
b) Name the C₄ acid formed through this pathway.
c) Name the enzyme involved in the formation of C₄ acid.
Answer:
a) It is the Partial oxidation of glucose into 2 molecules of Pyruvic acid.
b) Cytoplasm

Question 13.
Aerobic respiration and anaerobic respiration are two types of respiration.
a) What is anaerobic respiration?
b) Write the change that occurs to pyruvic acid in yeast cells.
Answer:
a) Anaerobic respiration is the respiration taking place without the involvement of oxygen.
b) Pyruvic acid is converted to Ethanol and CO₂

Question 14.
Notice the three stages of Calvin cycle given below:
a) Arrange the above stages in correct order.
b) Kelvin cycle is also known as C₃ cycle (Pathway). Give reason.
Answer:
a) Carboxylation, Reduction, Regeneration
b) First CO₂ fixation product is a C₂ acid or 3PGA. Hence it is called as C₂ cycle

Question 15.
Match the items of column A with B :

Answer:

Question 16.
Cell theory was formulated by two scientists.
a) Name the scientists.
b) Write the two main points in cell theory.
Answer:
a) Schleiden and Schwann
b)
1. All living organisms are composed of cells and their products
2. All cells arise from pre-existing cells

III. Answer any 3 questions from 17 to 20. Each carries 3 scores. (3 × 3 = 9)

Question 17.
Observe the figures A and B.

a) Identify the aestivation A and B.
b) Write one peculiarity of A.
c) Name the three kinds of petals in B.
Answer:
a) A.Twisted
B. Vexillary
b) In twisted aestivation, the one margin of the appendage overlaps the next one and so on .
c) In this the largest petal (standard petal) overlaps the two lateral petals (wing petals) which in turn overlap the two smallest anterior petals (keel petals)

Question 18.
The plant growth regulators are divided into growth promoters and growth inhibitors.

a) Name the three hormones, which are known as plant growth promoters.
b) Name the growth inhibitor which is known as ‘stress hormone’.
c) Write any two roles of the above identified stress hormone.
Answer:
a) Auxin, Gibberellin, Cytokinin
b) Abscisic acid (ABA)
c) 1) It promotes abscission and dormancy.
2) It acts as inhibitor of plant metabolism

Question 19.
Observe the figures A and B given below:

a) Name the type of venation in A and B.
b) Define venation.
Answer:
a) A.Reticulate
B. Parallel
b) Arrangement of veins and veinlets in the lamina of leaf

Question 20.
Observe the figure given below:

Write any three features on mesophyll cells from the figure.
Answer:

1. Mesophyll possesses chloroplasts of two types palisade parenchyma and spongy parenchyma.
2. Numerous large space and air cavities are found between spongy cells.
3. Palisade parenchyma arranged to wards daxial side.

Teachers recommend solving Kerala Syllabus Plus One Botany Previous Year Question Papers and Answers Pdf September 2021 to improve time management during exams.

Kerala Plus One Botany Previous Year Question Paper September 2021

I. Answer any 3 questions from 1 to 6. Each carries 1 score. (3 × 1 = 3)

Question 1.
Obseve the first pair and fill in the blank.
Lichen : association with fungi and algae.
______ : association of fungi with roots of higher plants.
Answer:
Mycorrhiza

Question 2.
Fill in the blank.
DNA synthesis take place in the ______ phase of cell cycle.
Answer:
S-phase

Question 3.
Name the plant hormone which helps to the ripening of fruits.
Answer:
Ethylene

Question 4.
Fill in the blank.
A flower having both feynoecium and Androecium is _____
Answer:
Bisexual flower

Question 5.
Name a bacteria responsible for nitrification.
Answer:
Nitrosomonas/nitrobactor

Question 6.
Name the unicellular fungus used for making bread.
Answer:
Yeast

II. Answer any 9 questions form 7 to 24. Each carries 2scores. (9 × 2 = 18)

Question 7.
Complete the table withappropriate terms:
Answer:
(a) Green Algae
(b) Phaeophyceae
(c) Red algae
(d) Laminarin/Mannitol

Question 8.
The arrangement of veins and veinlets in the lamina of leaf is termed as venation. Write any two types of venation.
Answer:
Recticulate and Parallel Venation

Question 9.
Match the folloiwng:

Answer:

Question 10.
Mitochondria is known as the power house of the cell. Why?
Answer:
They produce cellular energy in the form of ATP, stored and distributed for various cell activities hence they are called power houses of the cell.

Question 11.
Write any two functions of cell membrane.
Answer:
Cell growth, formation of intercellular juctions, secretion, endocytosis, cell division, transport of the molecules (Any two)

Question 12.
Light reaction is process involved in photosynthesis.
(a) What is light reaction?
(b) Where does it take place
Answer:
(a) It is the first step of photosynthesis in which trapping of light energy takes place and the synthesis of ATP and NADPH
(b) Grana membrane

Question 13.
In some plants that are adpted to dry tropical region have the C₄ pathway.
(a) Name the special type of anatomy seen in C4 plants.
(b) List out any two plants that shows C₄ pathway.
Answer:
(a) Kranz Anatomy
(b) Maize and sorghum

Question 14.
Sigmoid curve of growth is a characteristic of living organism growing in natural environment. Write any two phases seen in sigmoid growth curve.
Answer:
Lag phase/Exponential phase/Stationary phase (Anty two)

Question 15.
Write any two events take place in z-scheme of light reaction.
Answer:

1. Formation of ATP and NADPH
2. Splitting of water and release of oxygen.

Question 16.
Water movement in the root layer to xylem occurs by two distinct pathways. Which are they?
Answer:

1. Apoplast
2. Symplast

Question 17.
Write any two functions of Mesosomes.
Answer:
It helps in

1. Cell wall formation
2. DNA replciation and distribution to daughter cells
3. Respriation
4. Secretion (any two)

Question 18.
The Calvin cycle represents the main events in Dark reaction.
(a) Name the three main stages of Calvin cycle.
(b) What is the main product of Calvin cycle?
Answer:
1. Carboxylation
2. Reduction
3. Regeneration

b) Sucrose/ Starch

Question 19.
Agar is a commercial product obtained from algae.
(a) Name one alga from which agar is obtained.
(b) Write any one use of agar.
Answer:
(a) Gelidium Gracilaria
(b)

1. Use to grow microbes
2. Preparations of ice-creams and jellies.

Question 20.
Differentiate endarch and exarch xylem.
Answer:
In Endarch condition, protoxylem lies towards the centre (pith) and the metaxylem lies towards the periphery of the organ. eg. stem. In Exarch condition, protoxylem lies towards periphery and metaxylem lies towards the centre. eg. root.

Question 21.
Observe the figure. Identify the types to vascular bundles.

Answer:
(a) Radial
(b) Conjoint open

Question 22.
Differentiate between Heartwood and sapwood.
Answer:
The central dark coloured, durable and non functional wood is heart wood.
The peripheral light coloured, less durable and functional wood is sap wood.

Question 23.
Name the products obtained from anaerobic respiration by Yeast.
Answer:
Ethanol and CO₂

Question 24.
The girue below shows three types of facilitated diffusion. Identify the type of movement seen in (a) and (b).

Answer:
(a) Antiport
(b) Symport

Answer any 3 questions from 25 to 30. Each carries 3 scores. (3 × 3 = 9)

Question 25.
What are the fifferences between aerobic respiration and anaerobic respiration?
Answer:
In aerobic respiration glucose is breakdown in the presence of oxygen to produce carbon dioxide and water and more amount of energy.
In anaerobic respiration glucose is breakdown in the absence of oxygen to produce carbon dioxide, lactic acid, and ethanol (depends on type of micro-organism) and less amount of energy.

Question 26.
Given below is the floral formula of a plant in a particular family.

(a) Identify the family.
(b) Write any two floral characters of the family
Answer:
(a) Fabaceae
(b) Zygomorphic, 5 petals papilionaceous, vexillary aestivation diadelphous stamen and marginal placentation (any two)

Question 27.
The figure shown below is the diagrammatic view of an important phase of mitosis.
(a) Identify the phase.
(b) What are the key events occurring during this phase?
Answer:

(a) Metaphase
(b) Spindle fibres attach to kinetochores of chromosomes.
Chromosomes are arranged at spindle equator.

Question 28.
What are the criteria used for identifying essentiality of elements?
Answer:
(a) The element must be supporting normal growth and reproduction.
(b) The requriement of the element must be specific.
(c) The element must be directly involved in the metabolism of the plant.

Question 29.
The respiratory quotient depends upon the type of substrate used during respiration.
(a) Define RQ (Respiratory quotient)
(b) What is the RQ of carbohydrte during respiration?
Answer:
(a) The ratio of the volume of CO₂ evolved to the volume of O₂ consumed in respiration is called the respiratory quotient.
(b) 1

Question 30.
The various functions of plant growth regulaters are given below. Arrange them under suitable columns in the table provided.(i) Intermode elongation of sugarcane
(ii) Promotes cell division
(iii) Bolting
(iv) Apical dominance
(v) Initiate rooting in stem cutting
(vi) Overcome apical dominance

Answer:

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Kerala Plus One Botany Previous Year Question Paper June 2022

I. Answer any three questions from 1 to 4. Each carries 1 score. (3 × 1 = 3)

Question 1.
Fill in the blank.
Diffusion of water across a differentially or selectively Permeable membrane is ____.
Answer:
Osmosis

Question 2.
Choose the correct answr. Reserve Food in Phaeophyceae (Floridean starch, Mannitol, Starch, Algin)
Answer:
Mannitol

Question 3.
Observe the first pair and fill the blank.
Light reaction: Grana
Dark reaction: ____
Answer:
Stroma

Question 4.
Name the process which is common for both aerobic and anaerobic respiration.
Answer:
Glycolysis

II. Answer any 9 questions from 5 to 17. Each carries 2 scores. (9 × 2 = 18)

Question 5.
Plants adapted to dry tropical regions exhibit C₄ pathway.
(a) Name the first CO₂ acceptor in C₄ Pathway.
(b) Which is the first stable product formed in C₄ Pathway?
Answer:
a) PEP (Phospho enol Pyruvic acid)
b) OAA (Oxalo Acetic Acid)

Question 6.
Define Mycorrhiza. How is Mycorrhizal associaton helpful to plants?
Answer:
Mvcorrhiza
It is the syymbiotic association between fungi and roots of higher plants like pinus. Due to the presence of large surface area of hyphae, they helps to absorb water and minerals from soil Roots in turn gives sugar & N- containing compounds to fungus.

Question 7.
Differentiate between long day plants and short day plants.
Answer:

1. Long day plants : They require the exposure to light for a period greater than critical duration (12 hr) before flowering.
2. Short day plants: They require the exposure to light for a period less than critical duration before the flowering.

Question 8.
Match the following:

Answer:

Question 9.
List out the four components of xylem in angiosperms.
Answer:

1. Xylem vessels.
2. Xylem tracheids.
3. Xylem parenchyma & Xylem fibres.

Question 10.
Given below are certain processes that occur during the differnt phases of Prophase I in meiotic division. Arrange them against appropriate stages provided in the table.
• Crossing over
• Formation of synapsis
• Terminilisation of Chiasmata
• Dissolution of synaptomal complex.
Answer:

Question 11.
Write any two uses of Bacteria.
Answer:

• It helps in the conversion of milk to curd.
• It helps in the production of antibiotics.

Question 12.
Define Respiratory Quotient. Write the RQ value of Carbohydrate.
Answer:
Respiratory quotient It is the ratio of volume of CO₂ evolved to the volume of O₂ constimed in respiration
RQ of carbohydrate = 1

Question 13.
List out the four stages of M phase of cell cycle in correct sequential order.
Answer:
Prophase, Metaphase, Anaphase, Telophase

Question 14.
Observe the given diagram of Mitochondria.
(a) Identify and label parts A and B.
(b) Why Mitochondria is known as the power house of the cell?

Answer:
a) (A) Matrix
(B) Crista

b) Huge energy produced in the form of ATP and stored

Question 15.
How do conjoint vascular bundles fiffer from radial vascular bundels?
Answer:

• Conjoint vascular bundle : Xylem and Phloem are arranged in the same bundle on the same radius. Here phloem is located on the outer side of Xylem
• Radial vascular bundle : Xylem & Phloem are arranged in separate bundles on different radius.

Question 16.
Write any two peculiarities of facemose inflorescence.
Answer:

• Peduncle has unlimited growth.
• Flowers are arranged in Acropetal succession.

Question 17.
List any two functions of cell wall in plant cells.
Answer:

1. Give shape to the cell
2. Protects the cell from mechanical damage and infection.

Answer any 3 questions from 18 to 22. Each carries 3 scores. (3 × 3 = 9)

Question 18.
Given below are certain activities of growth regulators in plants. Arrange them under suitable heading in the table provided.
• Initiate rooting in stem cuttings.
• Bolting in rosette plants.
• Apical dominance.
• Increase length of grape stalks
• Pathenocarpy in tomatores.
• Speed up malting process in brewing industry
Auxin:
Gibberellin:
Answer:

1. Auxin : Initiate rooting in stem cuttings, Apical dominance, Parthenocarpy in tomatoes
2. Gibberellin : Bolting in rosette plants, Increase length of grape stalks, Speed up malting process in brewing industry

Question 19.
Write any three differences between cyclic and non- cyclic photophosphorylation.
Answer:

Question 20.
Define Hydroponics. Write any two appli-cations of hydroponics.
Answer:
Hydroponics It is the soilless cultivation of plants in nutrient medium

1. It helps to study deficiency symptoms in plants
2. Commercial production of vegetables such as tomato, seedless cucumber & lettuce.

Question 21.
List out any three modifications of root with one example each.
(a) Identify and write the compounds A and B in the cycle.
(b) Name the scientist who first elucidated the cycle.
(c) Where does tricarboxylic cycle occur?
Answer:
Roots are modified for

1. Mechanical support
   • Prop roots : In banyan tree, adventitious roots are modified and provide mechanical support
   • Stilt roots : In maize and sugarcane adventitious roots are supporting and coming out from the lower nodes of the stem.
2. Storage of food
   • In carrot, turnips tap roots are modified for food storage
   • In sweet potato adventitious roots are swollen and store food.
3. Respiration
   • Rhizophora growing in swampy areas, many roots dome out of the ground and grow vertically upwards. Such roots are called

Question 22.
Given below is the schematic representation of tricarboxylic acid cycle in respiration.

Answer:
a) A cjtric acid B Succinic acid
b) Hans Kreb
c) Matrix of Mitochondria

Teachers recommend solving Kerala Syllabus Plus One Botany Previous Year Question Papers and Answers Pdf March 2023 to improve time management during exams.

Kerala Plus One Botany Previous Year Question Paper March 2023

I. Answer any three questions from 1-5. Each carries 1 score. (3 × 1 = 3)

Question 1.
Fill in the blank:
The algal component in lichen is known as _____
Answer:
Phycobiont

Question 2.
Choose the correct answer:
The R.Q (Respiratory Quotient) of carbo-hydrate is ______ .
Answer:
1

Question 3.
Observe the relationship of first pair and fill in the blank:
Algin : Brown algae
Carrageen : _______
Answer:
Red algae

Question 4.
Name the type of vascular bundle in the figure:

Answer:
Radial vascular bundle

Question 5.
Fill in the blank:
The site of dark reaction in photosynthesis is _____ part of chloroplast.
Answer:
Stroma

II. Answer any 9 questions from 6-16. Each carries 2 scores.

Question 6.
Expand the following:
(A) PPLO
(B) SER
Answer:
(A) Pleuro Pneumonia Like Organism
(B) Smooth Endoplasmic Reticulum

Question 7.
Observe the diagram given below:
(i) Identify this bryophyte.
(ii) Label the parts A, B and C

Answer:

1. Funaria
2. A – Rhizoid B – Seta C – Capsule

Question 8.
Match the following:

Answer:

Question 9.
Fill in the blanks with appropriate term given below: Chloroplast, Amyloplasts, Lencoplast, Aleuroplast.

Answer:
A – Chloroplast
B – Leucoplast
C – Amyloplast
D – Aleuroplast

Question 10.
Karyokinesis in Mitosis involves four stages. What are they?
Answer:
Prophase, Metaphase, Anaphase, Telophase

Question 11.
The following figure A & B show two different types of phyllotaxy:
(i) Define phyllotaxy.
(ii) Write the name of phyllotaxy A & B

Answer:

1. Arrangement of leaves on stem or branch.
2. A – Alternate,
   B – Opposite

Question 12.
Write any two uses of Ethephon.
Answer:

1. Promote abscission in flowers and fruits.
2. Promote female flowers in cucumbers and thus increase the yield.

Question 13.
The first step in respiration is glycolysis.
(A) Define glycolysis.
(B) Write the site of glycolysis in a cell.
(C) Enzyme responsible for conversion of glucose to glucose -6-phosphate.
Answer:
(A)It is the partial oxidation of glucose into two molecules of Pyruvic acid.
(B) Cytoplasm
(C) Hexokinase

Question 14.
Certain physiological effects in plants are given below: Name the plant growth regulators responsible for it.
(A) Bolting
(B) Apical dominance
(C) Ripening of fruit
(D) Closure of stomata
Answer:
(A) Gibberellin
(B) Auxin
(C) Ethylene
(D) Abscisic acid

Question 15.
Identify the sub stages of prophase I of Meiosis in which the following events take place:
(A) Crossing over
(B) Pairing of homologous chromosome
(C) Terminalisation of Chiasmata
(D) Dissolution of synaptonemal complex.
Answer:
(A) Pachytene
(B) Zygotene
(C) Diakinesis
(D) Diplotene

Question 16.
Some characteristic features of C₃ and C₄ plants are given below:
• Kranz anatomy absent
• Lack photorespiration
• First product of CO₂
• Primary CO₂ acceptor is PEP.

Arrange them as follows:
C₃ Plants:
C₄ Plants:
Answer:
C₃ Plants : Kranz anatomy absent, First product of CO₂ fixation is PGA

C₄ Plants: Lack Photorespiration , Primary CO₂ acceptor is PEP

III. Answer any 3 questions from 17-20. Each carries 3 scores. (3 × 3 = 9)

Question 17.
The given figure shows different types of flowers based on position of floral parts on thalamus:
Answer:
(i) Identify (A) & (B).
(ii) Explain Epigynous flower.

(ii) Margin of thalamus grows upward enclosing the ovary completely and other parts arise above the ovary.

Question 18.
Write any 3 external and internal features that affect photosynthesis.
Answer:

Question 19.
The following are the anatomical features of flowering plants. Arrange these features in the table given below:
• Spongy parenchyma
• Hypodermis present
• Exarch xylem
• Conjoint and open vascular bundle
• Large empty bulliform cells
• Endodermis with casparian strip
Answer:

1. Root : Exarch xylem , Endodermis with casparian strip
2. Stem : Hypodermis present, Conjoint and Open vascular bundle
3. Leaf : Spongy parenchyma , Large empty bullifoTm cells

Question 20.
Observe the figure given below and answer the following questions.

(i) Write the name of this cycle.
(ii) Identify A & B in the cycle.
Answer:
(i) Krebs’ cycle/ TCA cycle

(ii) A – Oxalo acetic acid
B – Citric acid

Reviewing Kerala Syllabus Plus One Chemistry Previous Year Question Papers and Answers Pdf March 2019 helps in understanding answer patterns.

Kerala Plus One Chemistry Question Paper March 2019

Answer all questions from 1 to 7. Each question carry one score. (7 × 1 = 7)

Question 1.
The lowest hypothetical temperature at which gases are supposed to occupy zero volume is called
Answer:
-273.15° c. Absolute zero temperature.

Question 2.
Which among the following is a molecular hydride?
b) NH₃
c) CrH
d) LaH₂
Answer:
b) NH₃

Question 3.
Give the IUPAC name of

Answer:
3, Ethyl 1, 1 – dimethyl cyclo hexane

Question 4.
Predict the product obtained by the reaction of Li with O₂.
Answer:
Li₂O

Question 5.
According to the first law of thermodynamics, for an isolated system, ∆u = ………
Answer:
zero.

Question 6.
The minimum value for the product of uncertainties in position and momentum of a moving microscopic particle is equal to …………
Answer:
\(\frac{h}{4π}\)

Question 7.
Round off 0.0525 to a number with two significant figures.
Answer:
0.052

Answer any ten questions from 8 to 20. Each carries two scores (10 x 2 = 20)

Question 8.
Draw the Newman projections of the eclipsed and staggered conformations of ethane molecule.
Answer:
Newman Pojection Formula

Question 9.
Calculate the pH of 1 × 10^-2 molar aqueous solution of H₂SO₄
Answer:
pH = -log[H⁺]
= log[2 × 10^-2] = 1.699

Question 10.
Among NaCl, BeCl₂ and AlCl₃ which one is more covalent? Justify the answer.
Answer:
AlCl₃. Fajans Rule says that smaller the size and greater the charge of cation greater will be the polarising power, hence the covalent character.

Question 11.
Differentiate homolytic cleavage from heterolytic cleavage of covalent bonds.
Answer:

Question 12.
Mention two observations which could not be explained by the wave nature of electromagnetic radiations.
Answer:
Black body radiation, photo electric effect, atomic spectra, hot body radiation, line spectrum, reflection, Compton effect, (any two)

Question 13.
Chlorine has the most negative electron gain enthalpy. Justify the statement.
Answer:
In chlorine the incoming electron enters into 3p orbital which is larger than 2p of Flourine atom. So repulsion is low and Cl has highest electron gain enthalpy.

Question 14.
Write the expression for equilibrium
4NH_3(g) + 5O_2(g) → 4NO_(g) + 6H₂O_(g)
Write the expression for eqilibrium constant (K_c) for the above equilibrium. What happens to K_c, if the balanced equation is multiplied throughout by a factor, 2.
Answer:

Question 15.
Give the chemical equations for the steps involved In the ozonolysis of propene.
Answer:

Question 16.
Draw the structure of Diborane. Write a note on the nature of bonds present in it.
Answer:

Two types of bonds are present in diborane.
i) Two centre – two electron bonds (2c – 2e)
ii) Three centre – two electron bonds (3c – 2e)
In B₂H₆ four hydrogen atoms in one plane. These hydrogen atoms are known as terminal hydrogen. The other two hydrogen atoms which is above and below the plane are called bridging H atoms.

Question 17.
What is meant by spontaneous processes? Give the criterion of spontaneity in terms of ∆G for a process taking place at constant temperature and pressure.
Answer:
A process that take,s place without the help of any external agency is called a spontaneous process. The conditions for a spontaneous process is
∆G = -ve or ∆G < 0

Question 18.
Give the relation between molar-mass of a gas (m) and its density (d). How are the densities of 02(g). and CH_4(g) related, if they are kept at the same temperature and pressure?
Answer:
PM = dRT
P – Pressure,
M – Molar Mass,
d – density,
R – Universal gas constant,
T – Temperature.
d₁ = 2d₂
\(\frac{M_1}{M_2}\) =\(\frac{d_1}{d_2}\) → \(\frac{32}{16}\) = \(\frac{d_1}{d_2}\)
Density = 2:1

Question 19.
Represent, the Lewis structure of O₃ molecule and assign the formal charge on each atom.
Answer:
Lewis structure of ozone is

Formal Charge = Total no. of valence electrons on the free atom – Total no. of lone pair of electrons – \(\frac{1}{2}\)(Total no. of bonding electrons)

Formal charge on first O atom = 6 – 2 = \(\frac{1}{2}\) (6) = 1

Formal charge on 2nd O atom = 6 – 4 – \(\frac{1}{2}\) (4) = 0

Formal charge on 3rd O atom = 6 – 6 – \(\frac{1}{2}\) (2) = 1

Question 20.
Identify the positions of Al (z = 13) and S (z = 16) in the periodic table with the help of their electronic configurations. Predict the formula of the compound formed between them.
Answer:
Electronic configuration of Al₁₃ is 1s², 2s², 2p⁶, 3s², 3p¹. It is a p block element because last electron enters in p subshell.
Period no. 3 (Highest principal quantum no.)
Group No.: 13 (No. of valence electrons + 10)
Electronic cinfiguration of S16 – 1s², 2s², 2p⁶, 3s², 3p⁴.
p block element, period No. 3 and group no. 16
The compound formed by Al and S is Al₂S₃ because
valency of Al = 3 and that of S = 2.

Answer any seven questions from 21 to 29. Each carries three scores. (7×3 = 21)

Question 21.
Give reasons for the anomalous behaviour of Li. Write any four points of similarities between Li and Mg.
Answer:
Anomalous properties of Li are due to its small size, high ionisation enthalpy, high polarising power and absence of vacant d orbitals.
Anomalous properties of Li and Magnesium
i) Both Li and Mg are harder
ii) Both react slowly with water
iii) They do not form super oxides
iv) Their chlorides are deliquescent
v) Their bicarbonates are stable only in solution

Question 22.
Explain the hydrolysis of different types of salts with the help of examples and comment on the pH of the resulting solutions in each case.
Answer:
There are four types of salts
i) Hydrolysis of salts of strong base and weak acid.
eg. CH₃COONa, Na₂CO₃, KCN
These salts on hydrolysis give strong base and weak acid, hence the pH of resulting solution is ‘ as that of base, greater than 7.

ii) Hydrolysis of salts of weak base and week acid.
eg. NH₄Cl, NH₄NO₃, CuSO₄ etc.
These salts on hydrolysis gives weak base and strong acid and there fore pH of resulting solution is of less than 7.

iii) Hydrolysis otsalts of weak base and strong acid, eg. Ammonium Acetate (CH₃COONH₄), ammonium carbonate (NH₄)₂CO₃. These salts on hydrolysis give neutral solution.

iv) Hydrolysis of salt of strong acid and strong base. These salts do not undergo hydrolysis and the solution is neutral.

Question 23.
a) What is meant by acid rain?
b) Explain the chemistry behind the formation of acid rain.
c) What are the harmful effects of acid rain?
Answer:
a) If the pH of the rain water drops is below 5.6 it is called acid rain.

b) Oxides of nitrogen and sulphur are mainly responsible for acid rain.

c)
i) Acid rain is harmful for agriculture, trees and plants.
ii) It causes skin cancer
iii) It affects plants and animal life.
iv) Damages buildings and other structures

Question 24.
Alkynes can be converted selectively into cisalkenes and trans-alkenes. Explain with suitable examples.
Answer:
Lindlar catalyst gives cis product.

If the reduction is carried out using sodium in liquid ammonia, we get trans alkene.

Question 25.
A reaction mixture for the production of NH₃ gas contains 250g of N₂ gas and 50g of H₂ gas under suitable conditions. Identify the limiting reactant, if any and calculate the mass of NH₃ gas produced.
Answer:

H₂ is completely’consumed, so it is the limiting reagent.
Amount of ammonia formed = 50 + 233.33 = 283.33g

Question 26.
Write the molecular orbital electronic configuration, of N₂ and O₂ molecules. Compare the stability and magnetic behaviour of these molecules on the basis of M.O theory.
Answer:
Molecular orbital configuration of N₂ is
σ 1s² σ * 1s² σ 2s² σ * 2s² π 2px² = π2py² σ2pz²
Bond order = \(\frac{1}{2}\)(nb – na)
= \(\frac{1}{2}\)(10 – 4) = 3
Due to the pressence of paired electron, the molecule is diamagnetic.
Molecular orbital configuration of O₂

Question 27.
a) Why do real gases deviate from ideal behaviour?
b) Write the conditions under which gases deviate from ideality.
c) Define Boyle point.
Answer:
Due to two wrong assumptions
i) There is no force of attraction between the molecules.
ii) The actual volume of gas molecule is negligible compared to the total volume of the gas.
b) High pressure and low temperature.
c) It is the temperature at which the real gases obey ideal gas equation over a range of pressure.

Question 28.
Give the structure, a method of preparation and a chemical reaction of H₂O₂.
Answer:
Open book like structure or laptop structure.

Chemical reaction
H₂O₂ decomposes slowly on exposure to light.
2H₂O_2(l) → 2H₂O_(l) + O_2(g)

Preperation of hydrogen peroxide
By acidifying barium peroxide with H₂SO₄
BaO₂.8H₂O(s) + H₂SO₄(aq) → BaSO₄ + H₂O₂(aq)

Question 29.
Balance the following Redox process by ion-electron method or oxidation number method :
P_4(S) + OH^–_(aq) → PH_3(g) + HPO^–_2(aq)
Answer:
Oxidation no. method
i) Write the equation P₄ + OH^– → PH₃ + HPO₂
ii) Write the oxidation no. of each element and identify atoms which undergo oxidation or reduction.
P°₄ + OH^– → P^-3H₃ + H^-2PO₂
iii) Calculate the change in oxidation no. per atom and equate them by multiplying with suitable coefficient.

iv) Now balance the hydrogen atoms by adding 12 water (H₂O) molecules on L.H.S.
5P₄ + 12OH^– + 12H₂O → 8PH₃ + 12HPO₂
Now the equation is balanced.

Question 30.
Explain quantum numbers. Give the importance of quantum numbers in Pauli’s Exclusion Principle.
Answer:
Quantum numbers are the address of the electron. It is used to explain the size, shape, spin and orientation of an electron.
Quantum numbers are four
i) Principal quantum no (n) gives us idea about size and energy of electron in an orbit. The values can be 1, 2, 3, 4, 5, etc.
ii) Azimuthal Quantum No. (I): It gives the shape of the orbital. It is also called the orbital angular momentum quantum no. I can have values from 0 to (n -1).
iii) Magnetic quantum No. (m): It gives orientation of orbitals in space, m can have values from -I to +l including zero. There are (2I + 1) possible values.
iv) Spin Quantum no. (s): It gives the spin orientation +of electrons. It can have two values + \(\frac{1}{2}\) or – \(\frac{1}{2}\)
Paul’s exclusion principle : No two electrons in an atom can have same set of four quantum nos.

Or

If two electrons have same values for n, I and m they should have different values for s. ie. s = + \(\frac{1}{2}\) for first electron and – \(\frac{1}{2}\) for second electron.

Question 31.
a) What are silicones?
Answer:
Silicones are organo silicon polymers with -R₂SiO- repeating unit.

b) Write the chemical equations showing the steps involved in the manufacture of silicones.
Answer:

c) How can the chain length of silicones be controlled during their synthesis?
Answer:
By adding (CH₃)₃SiCl the chain length can be controlled.

Question 32.
Briefly explain the different types of structural isomerism shown by organic compounds with suitable examples.
Answer:
Structural isomerism are of four types
a) Chain Isomerism : Isomers differ in carbon chain
eg. Pentane – C₅H₁₂

b) Position Isomerism: Isomers differ in the position of the side chain or functional group.

c) Functional group Isomerism: Isomers which differ in the functional group.

d) Metamerism: Isomers which differ in the number of carbon atoms around the functional group.

Question 33.
a) State Hess’ law of constant heat summation.
b) Calculate the standard enthalpy of formation of CH₃OH_(l) from the following data:

Answer:
Hess’s Law The law states that total enthalpy change for a physical or chemical process is same whether the reaction is taking place in a single step or several steps.

Reverse the equation (1) + equation (2) + equation (3) × 2, we get the required equation,
ie. 726 + -393 + -286 × 2 = -239 kg/mol