Kerala Plus Two Botany Question Paper March 2023 with Answers

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

Kerala Plus Two Botany Previous Year Question Paper March 2023

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

Choose the correct answer:
Question 1.
The residual persistent nucellus is called _____. (Pericarp, Tapetum, Scutellum, Perisperm)
Answer:
Perisperm

Question 2.
Fill in the blank :
The process of breaking down of detritus into smaller particles is called _____.
Answer:
Fragmentation

Question 3.
Name the technique used to separate the fragments of DNA.
Answer:
Gel electrophoresis

Question 4.
Fill in the blanks:
Interaction between sea anemone and clown fish is an example for _____ interaction.
Answer:
Commensalism

Question 5.
Name the ‘cry’ gene that control corn borer insects.
Answer:
crylAb

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

Question 6.
Differentiate between grazing food chain and detritus food chain.
Answer:
Grazing Food Chain
It starts with producer belongs to first trophic level

Detritus Food Chain
It starts with dead organic matter belongs to first trophic level.

Question 7.
List out any two devices in plants, which help to discourage self-pollination and to encourage cross pollination.
Answer:

1. Pollen release and stigma receptivity are not synchronized.
2. Anther and stigma are placed at different position.

Question 8.
How can we make bacterial cell competent for trans- formation with recombinant DNA?
Answer:
Bacterial cells are treated with divalent cation such as Ca²⁺ to increase cell permeability. Then these cells are treated with recombinant DNA on ice. The cells and rDNA in ice are allowed to heat at 42°C Then return back to ice bath. Repeat this process.

Question 9.
Observe the given figure of ovule and label the parts (a), (b), (c) and (d).

Answer:
(a) Funicle
(b) Micropyle
(c) Embryo sac / Female gametophyte
(d) Chalaza

Question 10.
(a) Which is the thermostable enzyme used in PCR?
Answer:
Taq polymerase

(b) Name the bacterium from which the enzyme isolated.
Answer:
Thermus aquaticus.

Question 11.
Define productivity. What are the factors affecting primary productivity?
Answer:
The rate of biomass production is called productivity. Factors affecting primary productivity.

1. Environmental factors.
2. Availability of nutrients.

Question 12.
Explain the mechanism of insect resistance in Bt. cotton.
Answer:
Due to cry gene expression, insecticidal protein crystals are produced. In the Alkaline pH of insect
gut convert inactive protoxin into active toxin. Active Bt toxin binds to the midgut epithelium and causes cell lysis leading to death of insect.

Question 13.
Different types of population interaction has been observed in population. Write the type of interaction observed among the following species:

Species A	Species B	Type of Interaction
Orchid ophrys	Bees	(a)  _______
Ticks	Dogs	(b) _______
Barnacles	Whale	(e) _______
Fungus	Photosynthetic Algae	(d) _______

Answer:
(a) Mutualism
(b) Parasitism
(c) Commensalism
(d) Mutualism

Question 14.
The figure given below shows pyramid of energy. Pyramid of energy is always upright, can never be inverted. Give reason.

Answer:
When energy flow from one trophic level to the next level some energy is lost as heat at each step as 10%.

Question 15.
What are Genetically Modified Organisms(GMO)? Mention any one merit of GM plants.
Answer:
An organism whose genetic material is altered is called Genetically Modified Organism.
Made crops tolerant to abiotic stress.

Question 16.
The following graph shows two types of population growth curves.
(a) Name the growth curves (a)& (b)
Answer:
(a) (a)- Exponential growth
(b) Logistic growth

(b) What does ‘K’ stand for?

Answer:
K – Carrying capacity

III. Answer any 3 questions from 17 to 20. Each carries 3 scores.

Question 17.
Explain how Eli Lilly company produced genetically engineered insulin.
Answer:
Eli Lilly Company isolated DNA sequences corresponding to A and B chain of insulin. A and B Chain DNA were introduced in plasmids of E.coli to produce the polypeptide A and B chains: Polypeptide chain A and B were extracted. and combined by creating disulphide bonds to form genetically engineered insulin.

Question 18.
Wind pollinated flowers have many peculiarities. Write down any three such peculiarities.
Answer:
Flowers with well exposed stamens. Large feathery stigma to trap air-borne pollen grains. Flowers contain single ovule in one ovary and numerous flowers packed into an inflorescence e.g. corn cob.

Question 19.
Given below is a schematic representation which shows the factors influencing population density:

(i) Label (a) and (b)
Answer:
(a) – Mortality
(b) – Emigration

(ii) Which are the factors that contribute to an in crease in population density?
Answer:
Natality and Immigration

(iii) Define Natality.
Answer:
Natality – The number of births during a given period.

Question 20.
EcoRI is isolated from Escheritia coli RY 13. Explain the naming procedure of EcoRI.
Answer:
(E) – First letter represent genus of the bacteria.
(co) – First two letters represent the species of the organism.
(R) – Represent strain of bacteria.
Roman number (I) – Order in which enzyme is isolated.