Kerala Plus Two Botany Question Paper March 2021 with Answers

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

Kerala Plus Two Botany Previous Year Question Paper March 2021

Answer the following questions from 1 to 31 upto a maximum score of 30.
I. Each questions from 1 to 7 carries 1 score.

Question 1.
Choose the correct answer
The plant which flowers only once in their life time:
(a) Mango
(c) Coconut
(b) Bamboo
(d) Jackfruit
Answer:
Bamboo

Fill in the blank:
Question 2.
During sexual reproduction, the process of syngamy results in the formation of a diploid cell called _____
Answer:
Zygote

Question 3.
Name the process of breeding crops for improved food quality.
Answer:
Biofortification

Question 4.
Choose the correctly mathced pair from the following:
(a) Gel electrophoresis – Used to produce biological products in large quantity.
(b) Bioreactors – Separation of DNA fragments.
(C) PCR – Amplification of gene
Answer:
PCR-Amplification of gene

Question 5.
Observe the relationship between the first two terms and fill in the blank.
Mycorrhizae : Mutualism
Lice on humans : _______
Answer:
Parasitism

Question 6.
Fill in the blank.
The portion of embryonal axis above the level of cotyledons in dicot embryo is known as ______ .
Answer:
Epicotyl

Question 7.
Which of the following is a curative method of ADA deficiency?
(a) ELISA
(b) Autoradiography
(c) PCR
(d) Bonemarrow transplantation
Answer:
Bone marrow transplantation

II. Each question from 8 to 26 carries 2 scores each. (19 × 2 = 38)

Question 8.
Differentiate monecious and dioecious plants with an example for both.
Answer:

Monecious plants	Dioecious plants
Male and female	Male and female
flowers present on the same plant.	flowers present on different plants.
Example – Coconut	Example – Papaya

Question 9.
EcoRI is an example of Restriction enzyme. List out the criteria for naming a Restriction enzyme.
Answer:
First capital letter represents the genus name of the bacteria(Ecoli). Second two letters represent the species name of the bacteria ‘R’ represents the strain of the bacteria. ‘I’ the roman number represents the order of isolation of enzyme from the bacteria.

Question 10.
Expand MOET. Write its significance.
Answer:
MOET – Multiple Ovulation Embryo Transfer Technology.
Significance
To improve successful production of hybrids.
Overcoming the problems of normal mating.

Question 11.
Different stages of development in a dicot embryo are given below. Arrange them in the correct sequential order. Heart shaped embryo, globular embryo, mature embryo, pro-embryo
Answer:
Pro-embryo → Globular embryo → Heart shaped embryo → Mature embryo

Question 12.
Observe the diagrams (a) and (b) given below. Identify the type of gametes. Explain the feature of gametes seen in diagram ‘b’.
Answer:

(a) Isogàmetes or Homogametes
(b) Heterogametes
Features of heterogametes
Morphologically distinct gametes i.e., male gamete is the antherozoid or sperm and Female gamete is egg or ovum.

Question 13.
The females of placental mammals exhibit cyclical changes in the activities of ovaries and accessory ducts during the reproductive phase. Specify two types of cyclical changes present in these organisms with appropriate examples.
Answer:

• Oestrus cycle
  1.  It is shown by Non-primate mammals eg. Cows, Tiger etc.
• Menstrual cycle
  1. It is shown by Primates eg. Man Monkey etc.

Question 14.
Write any two critical research areas of bio technology.
Answer:
(i) Providing the best catalyst in the form of improved organism usually a microbe or pure enzyme.
(ii) Creating optimal conditions through engineering for a catalyst to act.

Question 15.
What is biomagnification? Name any one chemical that causes biomagnification.
Answer:
Biomagnification It refers to increase in concentration of the toxicant at successive trophic level. Eg. DDT, Mercury etc.

Question 16.
List any four reasons for deforestation.
വനനശീകരണത്തിനുള്ള നാലു കാരണങ്ങൾ എഴുതുക.
Answer:

1. Conversion of forest to agricultural land so as to feed the growing human population.
2. Trees are axed for timber.
3. Trees are axed for firewood.
4. Slash and burn agriculture or Jhum cultivation.

Question 17.
Fill in the blanks with appropriate symbols (+, -, 0) or name of interaction.

Species A	Species B	Name of population interaction
(a)  _____	(b)  ____	Mutualism
+	(c) ____	Parasitism
+	0	(d)  _____

Answer:
(a) +
(b) +
(c) –
(d) Commensalism

Question 18.
What is the structural difference between proinsulin and mature functional insulin?
Answer:
Proinsulin

• Consists of three polypeptide chains: chain A and chain B and chain C.
• Non functional Mature Insulin
• Consists of two polypeptide chains: chain A and chain B linked together by disulphide bridges.

Question 19.
The diagram given below is E. coli cloning vector pBR322.

Identify the selectable markers present in it. Explain the significance of ‘ori’.
Answer:
amp^R and tet^R ori – Origin of replication or DNA sequence from where replication starts.

Question 20.
State the important steps in decomposition.
Answer:
Fragmentation, leaching, catabolism, Humification and mineralization.

Question 21.
Write four peculiarities of insect pollianted flowers.
Answer:

• Flowers are Large Colourful
• Fragrant With nectar
• Pollen grains sticky
• Small flowers are clustered into an inflorescence

Question 22.
Banana is a parthenocarpic fruit. What are partheno carpic fruits? How can be parthenocarpy induced?
Answer:
Parthenocarpic fruit is fruit formed without fertilization, they are Seedless fruits. Parthenocarpy can be induced by application of growth hormones.

Question 23.
Self incompatibility is an outbreeding mecahnism seen in plants. Explain self incompatibility.
Answer:
Self incompatibility means the inhibition of pollen germination on stigmatic surface of the same flower. It is the Genetic mechanism to prevent self pollination.

Question 24.
Based on the nature of the habitat, succession of plants may be hydrarch or xerarch.
(a) Which is the pioneer community in xerarch succession?
(b) Explain hydrarch succession.
Answer:
(a) Lichen
(b) Hydrarch succession is the transformation of hydric area into a mesic (medium water condition) area.

Question 25.
Organisms belonging to different trophic levels are listed below. Arrange the organisms under appropri- ate headings in the table provided. Man, phytoplankton, Fish, Zooplankton

First Trophic level	Second Trophic level	Third Trophic level	Fourth Trophic level

Answer:

1st trophic level	2nd trophic level	3rd trophic level	4th trophic level
Phytoplankton	Zooplankton	Fish	Man

Question 26.
Catalytic converters are fitted in automobiles for reducing emission of poisonous gases.
(a) Name the catalysts used in catalytic converters
(b) What happens to the automobile exhaust when it passes through catalytic converters?
Answer:
(a) Platinum, Palladium and Rhodium.
(b) When exhaust passes through the catalytic converter
1. Unburnt hydrocarbons are converted into carbon dioxide and water.
2. Carbon monoxide is converted into Carbon dioxide.
3. Nitric oxide is converted into Nitrogen gas.

III. Each questions 27 to 31 carries 3 scores. (5 × 3 = 15)

Question 27.
The four basic processes that affect the population density are given below. Natality, Mortality, Emigration, Immigration. Which of the two processes contribute to a decrease in population density and explain them.
Answer:
Mortality and Emigration

1. Mortality – It is the number of deaths in the population during a given period.
2. Emigration – It is is the number of individuals of the population who left the habitat.

Question 28.
Bt cotton is a transgenic plant with insecticidal protein named Bt toxin.
(a) Name the specific gene which produce Bt toxin.
(b) Name the organism from which this gene is isolated.
(c) Explain the mechanism behind the insect resistance in Bt cotton.
Answer:
(a) Cry gene

(b) Bacillus thuringiensis

(c) Cry gene produce insecticidal protein crystals that exists as inactive protoxins, Once an insect ingest the protoxin it is converted into an active toxin due to the alkaline pH of the gut, The activated toxin binds to the surface of midgut epithelial cells and create pores that cause cell swelling and lysis and eventually cause death of the insect.

Question 29.
A typical microsporangium is surrounded by four wall layers. Name the wall layers and state the function. of the innermost wall layer.
Answer:
Epidermis, Endothecium, middle layers & Tapetum Tapetum-Nourishes the developing pollen grains.

Question 30.
Different steps in rDNA technology are given below. Arrange them in correct sequential order.
(a) Ligation of DNA frament into a vector
(b) Culturing of host cells in a medium at large scale
(c) Isolation of DNA
(d) Transferring the rDNA into the host
(e) Fragmentation of DNA
(f) Isolation of desired DNA fragment
Answer:
(c) Isolation of DNA
(e) Fragmentation of DNA
(f) Isolation of desired DNA fragments
(a) Ligation of DNA fragment into a vector
(d) Transferring the rDNA into the host.
(b) Culturing of host cells in a medium at large scale

Question 31.
Dairying is the management of animals for milk and its products for human consumption. List out various management measures that should be undertaken for a successful management of dairy farm.
Answer:

1. Selection of good breeds having high yielding potential and resistance to diseases.
2. Provide adequate water.
3. Maintained disease free condition.
4. Feeding should be in a scientific manner (in the quality and quantity of fodder).
5. Regular visit of a veterinary doctor.