Kerala Plus Two Botany Board Model Paper 2020 with Answers

Teachers recommend solving Kerala Syllabus Plus Two Botany Previous Year Question Papers and Answers Pdf Board Model Paper 2020 to improve time management during exams.

Kerala Plus Two Botany Board Model Paper 2020 with Answers

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

Question 1.
Choose the correct answer and fill in the blank.
_______ is the female gametophyte of angiosperms.
a) Embryo sac
b) Nuceluus
c) Integument
d) Pollen grain
Answer:
Embryosac

Question 2.
Choose the correct answer. Natural aging of a lake by nutrient enrichment of its water is called
a) Biomagnification
b) Algal bloom
c) Succession
d) Eutrophication
Answer:
Eutrophication

Question 3.
Fill in the blank :
The wheat variety having high protein content used as donor in bio-fortification is ______
Answer:
Atlas 66

Question 4.
Name the type interaction between an orchid plant and Mango tree.
Answer:
Commensalism

Question 5.
Find the odd one.
Hilsa, Sardine, Rohu, Mackerel
Answer:
Rohu

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

Question 6.
The innermost wall layer of Microsporangium is Tapetum.
a) What is it is function?
b) Features of Tapetal cells.
Answer:
a) It nourishes the pollen grain
b) It has dense cytoplasm, It posses prominent nucleus

Question 7.
Match the following:

A	B
Chlamydomonas	Gemmule
Conidia	Zoospore
Sponage	Bulbil
Hydra	Pencillium
	Buds

Answer:

A	B
Chlamydomonas	Zoospore
Conidia	Penicillium
Sponage	Gemmule
Hydra	Buds

Question 8.
Explain the terms:
a) Micro propagation
b) Totipotency
Answer:
a) It is the production of large number of plants within short time in tissue culture,
b) The ability of a cell to form whole plant.

Question 9.
Explain the separation of DNA fragments using gel electrophoresis.
Answer:
In Gel electrophoresis, negatively charged DNA fragments are separated by forcing them to move towards the anode under an electric field through a agarose matrix. The DNA fragments separate according to their sizd in agarose gel.

Question 10.
Write notes on:
a) Micro injection
b) Biolistics
Answer:
a) Micro-injection Recombinant DNA is directly injected into the nucleus of an animal cel.,

b) Biolistics – Cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA. It is suitable for plants.

Question 11.
Amplification of gene of interest is done using PCR.
a) Expand PCR
b) Mention the three steps of this process.
Answer:
a) Polymerase chain reaction

b) 1. Denaturation
2. Annealing
3. Extension

Question 12.
Observe the diagram and answer A and B.

Answer:
a) Pro-insulin
b) Mature insulin

Question 13.
a) Define transgenic animals.
b) Write any two uses of transgenic animals.
Answer:
a) Animals that possess manipulated gene (genetically modified) and express foreign gene are called as transgenic animals.
b) Transgenic animals are used in the field of

1. Biological products
2. Study of disease and
3. Normal physiology and development

Question 14.
Humification and Mineralisation occur during decomposition in the soil. Write the difference between these two processes.
Answer:
Humification
It is process by which simplified detritus is changed into dark coloured amorphous substance called humus. It is the reservoir of nutrients.

Minerilisation
It invoves the release of inorganic subtances (Water, CO₂, etc.) and other nutrients (NH₂⁺, Ca⁺⁺, Mg⁺⁺, K₊, etc.) in the soil.

Question 15.
a) Construct a grazing food chain using the following organisms: Bird, Grass, Grasshopper
b) Write the trophic level of grasshopper.
Answer:
a) Grass → GrasshopperBird
b) Second trophic level or primary consumer

Question 16.
Why is CNG better than diesel or petrol?
Answer:

1. CNG is better than diesel.
2. It burns most efficiently.
3. CNG is cheaper than petrol or diesel.
4. It cannot be adulterated like petrol or diesel.

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

Question 17.
Briefly describe the adaptations of desert plants.
Answer:

1. Thick cuticle on their leaf surfaces .
2. Stomata arranged in deep pits to minimise water loss.
3. They show CAM pathway (they open stomata during night and closed during daytime).
4. Leaves are reduced to spines and the flattened stems do photosynthesis.

Question 18.
Density of a population fluctuates due to changes in four basic processes.
a) Complete the diagram by adding the points ABC and D.
b) Explain A and D.

Answer:
a)

1. Natality
2. Mortality
3. Immigration
4. Emigration

b) A-lmmigration-Movement of individuals into the population.
D-Emigration- Movement of individuals out of the population.

Question 19.
Air pollution is a serious environmental issue. Give three harmful effects of air pollution.
Mention the out-breeding devices in plants to prevent self pollination, (any 3 points).
Answer:

1. Reduce the growth and yield of crops.
2. It cause premature death of plants.
3. Affect respiratory system of animals and humans!

Question 20.
Mention the out-breeding devices in plants to prevent self pollination. (any 3 points)
Answer:

1. Pollen release and stigma receptivity are not at the same time.
2. Anther and stigma are placed at different positions.
3. Self-incompatibility.
4. Production of unisexual flowers