Kerala Plus Two Botany Board Model Paper 2021 with Answers

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

Kerala Plus Two Botany Board Model Paper 2021 with Answers

Answer the following questions from 1 to 31 upto a maximum score of 30.
1. Questions 1 to 7 carry 1 score each.

Question 1.
Which among the following is a vegetative propagule?
(a) Rhizome
(b) Gemmules
(c) Zoospores
(d) Conidia
Answer:
Rhizome

Fill in the blank :
Question 2.
The protective wall layer of fruit is known as ____.
Answer:
Pericarp

Question 3.
Fruit which develop from any part of the flower other than ovary is called ____.
Answer:
False fruit

Question 4.
Name any two products obtained through Beekeeping.
Answer:
Honey and bee wax

Question 5.
Fill in the blank:
The restriction enzyme EcoRI isolated from the bac-terium _____.
Answer:
Escherichia coli RY 13

Question 6.
In recombinant DNAtechnology, DNAfragments are joined by the help of the enzyme.
(a) DNA ligase
(b) DNA polymerase
(c) Restriction enzyme
(d) Taq polymerase
Answer:
DNA ligase

Question 7.
Select the non-parasitic organism from the list given below:
(a) Lice
(b) Cuscuta
(c) Epiphytic orchid.
(d) Ticks
Answer:
Epiphytic orchid

II. Questions 8 to 26 carry 2 scores each.

Question 8.
In some organisms, female gamete undergoes de-velopment to form new organisms without fertiliza-tion. Name the phenomenon. Give an example.
Answer:
Parthenogenesis
eg. Honeybee and rotifers

Question 9.
Chromosome number in meiocytes and gametes of some organisms are given in the table. Fill in the blanks.

Name of organism	Chromosome number in meiocytes	Chromosome number in qametes
a. Rice	–	12
b. Onion	–	8
c. Apple	34	–
d. Maize	20	–

Answer:

Name of organism	Chromosome number in meiocytes	Chromosome number in qametes
a. Rice	24	12
b. Onion	16	8
c. Apple	34	17
d. Maize	20	10

Question 10.
There are two types of cyclic events that happens in the reproductive phase of female organismsamong placental mammals. Which are the cyclic events and give one example for each.
Answer:
Menstrual cycle-Primates eg. monkeys, apes Oesrous cycle – Non primates eg. cow, sheep

Question 11.
The outer layer of pollengrains is made up of’ sporopollenin. What is the importance of sporopollenin?
Answer:
It is one of the most resistant organic material which can withstand high temperature strong acid and al-kali. So the pollen grains are well preserved as fos-sils.

Question 12.
Differentiate between Autogamy and Xenogamy.
Answer:
Atutogamy: It is the transfer of pollen grains from the anther to the stigma of the same flower.
Xenogamy: Transfer of pollen grains from anther to the stigma of a different plant. This type of pollina-tion occurs between genetically different species.

Question 13.
If the female parent produces bisexual flowers, emas-culation is necessary in artificial hybridization.
(a) What is emasculation?
(b) Write down the importance of emasculation.
Answer:
(a) Anthers are removed before the dehiscence of bisexual flowers.

(b) It is helpful to avoid self pollination and fertilisation.

Question 14.
Fusion of polar nuclei with male gamete in double fertilisation result in formation of endosperm.
(a) Write down the function of endosperm.
(b) Write briefly about the endosperm development in coconut.
Answer:
(a) It gives nutrition to the developing embryo.

(b) PEN undergo successive nuclear divisions to give rise to free nuclei. This stage of endosperm v development is called free nuclear endosperm. Later cell wall formation occurs and the endosperm becomes cellular.

Question 15.
‘Hisardale’ is a new breed of sheep developed in Punjab.
(a) Identify the method by which the breed is devel-oped.
(b) Name the parental breeds of’Hisardale’.
Answer:
(a) Crossbreeding
(b) Bikaneriewes and Marino rams

Question 16.
In r-DNA technology, amplification of gene is done by a process called PCR.
(a) Expand PCR
(b) What are the three main steps involved in PCR?
Answer:
(a) Polymerase chain reaction
(b) Denaturation, Annealing and extension.

Question 17.
Observe the picture given below:
(a) Identify the instrument in the figure.
(b) Write any one use of this instrument.

Answer:
(a) Bioreactor

(b) It is the large culture vesel for large Scale production of Recombinant protein, enzyme etc.

Question 18.
List any two uses of GMO (Genétically Modified Or ganism) in agriculture.
Answer:
(i) Made crops more tolerant to abiotic stresses (cold, drought, salt, heat).
(ii) Reduced reliance on chemical pesticides (pest-resistant crops).

Question 19.
Expand GEAC. Mention its function.
Answer:
GEAC-Genetic Engineering Approval Committee. They take decisions regarding the validity of GM research and the safety of introducing GM organisms for public services.

Question 20.
Comment on Brood Parasitism with an example.
Answer:
In Brood parasitism parasitic bird lays its eggs in the nest of its host and the host incubate them. The eggs of the parasitic bird resemble the host’s egg in size and colour. So the host bird keep up it in their nest. Example of brood parasitism are cuckoo (koel) and the crow.

Question 21.
The figure shows simplified model of phosphorus cycle. Analyse the figure and fill up the blanks.

Answer:
a) Rock Minerals
(b) Producers

Question 22.
The figure given below indicates a pyramid of energy. Why pyramid of energy is always upright in
position?

Answer:
Pyramid of energy is always upright because when energy flows from a particular tropic level to the next tropic level. Some energy is always lost as heat at each step.

Question 23.
What is ecological succession? Differentiate Hydrarch succession and Xerarch succession?
Answer:
Ecological succession-It is the successive replace- – ment of plant communities in an area over a p eriod of time. Hydrarch – It involves the ecological succession in the newly formed pond or lake. Pioneer communi ty’- Phytoplanktons. Xerarch – It involves the ecological succession on bare rock surfaces. Pioneer community – Lichen.

Question 24.
‘Jhum’ cultivatjon/Slah and bum agriculture is an agricultural practice in north esatern states of India. How this practice enhances deforestation?
Answer:
In slash and burn agriculture, the farmers cut down the trees of the forest and burn the plant remains. The ash is used as a fertiliser and theland is then used for farming or cattle grazing. After cultivation, the area is left for several years so as to allow its recovery. The farmers then move on to other areas and repeat this process.

Question 25.
Write any four measures for controlling Global Warming.
Answer:

1. Cutting down use of fossil fuel.
2. Improving efficiency of energy usage.
3. Preventing deforestation and planting trees.
4. Slowing down the growth

Question 26.
In 1980 Government of India introduced a management programme, JFM.
(a) Expand JFM
(b) What is its significance?
Answer:
(a) Joint Forest Managment(JFM)

(b) This is helpful to local communities for getting
benefit of various forest products for the return of services and thus the forest can be conserved in a sustainable manner.

III. Questions 27 to 31 carey 3 scores each.

Question 27.
Pollination is the transfer of pollengrams from anther to stigma of pistil. Write any three adaptations seen in wind pollinated plants.
Answer:

1. Pollen grains are light and no-sticky.
2. Flowers have a single ovule in each ovary.
3. They possess well-exposed stamens and feathery stigma.

Question 28.
Different steps of plant breeding is given below;
(1) Testing, release and commercialization of new cultivais.
(2) Cross hybridization among the selected parents.
(3) Evaluation and selection of parents.
(4) Collection of variability
(5) Selection and testing of superior recombinants.
Create a flow chart of plant breeding from the above steps in sequential manner.

Answer:
(a) Evaluation and selection of parents.
(b) Cross hybridization among the selected parents.
(c) Selection and testing of superior recombinants.

Question 29.
Given diagram shows a technique used in r-DNA technology.

(a) Identify the process
(b) What is the purpose of this technique in r-DNA technokgy?
(c) Name the stain used in this technique for visualizing DNA under UV-light.
Answer:
(a) Gel electrophoresis
(b) In this cut fragments of DNA are separated.
(c) Ethidium bromide

Question 30.
Bt-cotton is a transgenic plant
(a) What does ‘Bt’ stands for?
(b) Explain the mechanism of insect resistance in Bt-cotton
Answer:
(a) Bacillus thuringiensis
(b) Bt toxin protein exist as inactive protoxins but it is converted into an active of form in the presence of the alkaline pH of insect gut. The activated toxin binds to the surface of midgut epithelial cells and create pores that cause cell swelling and lysis atid results in the death of insect.

Question 31.
Opuntia is a plant well adapted to desert conditions. Write down the various adaptation found in desert
plants.
Answer:
Desert plants have a thick cuticle on their leaf surfaces and stomata arranged in deep pits to minimise water loss through transpiration. They also have CAM pathway in which they open stomata during night and closed during time.