Kerala Plus Two Botany Board Model Paper 2023 with Answers

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

Kerala Plus Two Botany Board Model Paper 2023 with Answers

I. Answer any 3 questions from 1 to 5. Each carries 1 score.

Question 1.
Choose the correct answer. The innermost wall layer of microsporangium that give nutrition to pollen grain is called _____.
(a) Epidermis
(b) Endothecium
(c) Tapetum
(d) Middle layer
Answer:
Tetum

Question 2.
Name the first transgenic cow that produces human protein enriched milk.
Answer:
Rosie

Question 3.
Fill in the blank:
The natural interconnection of different food chains is called ______ .
Answer:
Food web

Question 4.
Choose the correct answer.
Which of these enzymes removes nucleotides from the ends of a DNA?
(a) Exonuclease
(b) Endonuclease
(c) DNA Ligase
(d) DNA Polymerase
Answer:
Exonuclease

Question 5.
Fill in the blank:
The population interaction in which one species is harmed whereas the other is unaffected is known as
Answer:
Amensalism

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

Question 6.
Write two roles of Predators in ecosystem.
Answer:
1. They plays an important role in biological control and reduce the size ofprey populations.
2. Predators maintain species diversity in nature.

Question 7.
(a) What is emasculation?
Answer:
(a) Removal of anthers from the flower bud before dehiscence.
(b) It frevert self pollination

Question 8.
Bt-toxin does not kill Bacillus, but it kill insects. Write the reason.
Answer:
The Bt toxin is producéd by the bacteria as inactive protoxin. Due to alkaline PH of insect gut, insecticidal protein crystals are Solubilised and convert inactive protoxin into active toxin. Active Bt toxin binds to the midgut epithelial cells and make pores, then swelling, it causes lysis and leads to the death of insect.

Question 9.
(a) Write the name of the ecological pyramid given in the figure.
(b) This pyramid is always upright. Why?

Answer:
(a) Pyramid of energy.
(b) when energy flows from one trop hic level to the next some energy is lost as heat at each step
hence energy deceases in uccessive trophic levels.

Question 10.
How can we visualize DNA fragments in G el electrophoresis?
Answer:
Separated DNA fragmentcan bevisualised as orange coloured band under UV light exposure after staining with Ethydium Bromide.

Question 11.
(a) Expand ELISA.
(b) What is the principle of this process?
Answer:
(a) Enzyme linked immuno-sorbent assay
(b)Antigen-antibody interaction

Question 12.
Observe the figure of Monocot seed and label the parts marked as A, B, C & D

Answer:
A—Endosperm
B — Scutellum
C — Plumule
D — Radicle

Question 13.
Write the differnce between Gross Primary Productivity (GPP) and Net Primary Productivity (NPP).
Answer:
Gross primary productivity : The rate of production of total organic matter during photosynthesis.
Net primary productivity : Gross primary productivity minus respiration losses. GPP — R = NPP

Question 14.
N_t+1 = N_t + [(B + 1) – (D + E)] is the equation to find the population density at a given time. What does B, I, D and E stands for?
Answer:
B — Natality I Birth rate
I — Immigration
D — Mortality I Death rate
E — Emigration

Question 15.
(a) Which’enzymes are known as ‘molecular scissors’?
(b) What is the use of thse enzymes in Genetic engineering?
Answer:
(a) Restriction enzymes
(b) They are used to cut at specific nucleotide sequence of DNA

Question 16.
Match the following:

A	B
Fragmentation	Water soluble inorganic nutrients go down into the soil
Leaching	Breakdown of detritus into smaller particles
Catabolism	Formation of inorganic nutrients from humus
Mineralisation	Bacterial and fungal enzymes degrade detritus into simpler inorganic substances

Answer:

A	B
Fragmentation	Breakdown of detritus into smaller particles
Leaching	Water soluble inorganic nutrients go down into the soil
Catabolism	Bacterial and fungal enzymes degrade detritus into simpler inorganic substances.
Mineralisation	Formation of inorganic nutrients from humus

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

Question 17.
(a) Observe the figure and write the name of two population growth curves marked as A & B.
(b) What does K and r stands for?

Answer:
(a) A— Exponential growth
B — Logistic growth.

(b) K — Carrng capacity
r — Intrinsic rate of natural increase

Question 18.
Write three adaptations of insect pollinated fldvers.
Answer:
Pollen grains are sticky. Flowers are large, brightly colou red. They have scent and rich in nectar. Small flowers present in cluster to make them conspicuous.

Question 19.
(a) Writethe name of the process given inthefigure.
(b) What is the purpose of this process in rDNA technology?
(c) What is the name of thermostabte DNA polymerase enzyme used in this technique?

Answer:
(a) Polymerase Chain Reaction
(b) Used for Amplification of DNA
(c) Taq Polymerase

Question 20.
Write three uses of Trangenic animals.
Answer:

1. Used to study the normal physiology and development.
2. Used to understand the role of a gene in the development of a disease.
3. Transgenic animals (mice) are used in testing the safety of vaccines and chemicals.