Kerala Plus Two Botany Question Paper March 2020 with Answers

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

Kerala Plus Two Botany Previous Year Question Paper March 2020

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

Question 1.
Which one of the following has the largest population in a food chain?
a) Products
b) Primary consumers
c) Secondary consumers
d) Tertiary consumers
Answer:
Producers or Primary consumers

Question 2.
Which among the fallowing is a selectable marker in pBR-322?
a) “Ori”
b) Hind III
c) amp^R
d) rop
Answer:
amp^R

Question 3.
____ is a better yielding semi dwarf variety of rice developed in India.
a) Sonalika
b) Kalyan Sona
c) IR-8
d) Jaya/iBco)
3. Jaya

Question 4.
What is a Clone?
Answer:
Morphologically and genetically similar offsprings are produced through asexual reproduction called as Clone

Question 5.
Fill up the blank suitably.
Mortality : No. of deaths in the population during a given period.
_________ : No. of births in the population during a given period.
Answer:
Natality or birth rate

II. Answer any9 questions from 6-16. Each carries 2 scores. (9 × 2 = 18)

Question 6.
What are the main consequences of Global warming?
Answer:
1. Melting of polar ice caps and Himalayan snow caps.
2. Rise in sea level and submerge many coastal areas.

Question 7.
What is the difference between hydrarch succession and xerarch succession.
Answer:
Xerarch succession : Succession that occurs in desert or xeric condition. The poineer community formed is Lichen.
Hydrarch : It is the ecological succession occur in the newly formed pond or lake . The poineer community formed is phytoplankton

Question 8.
Suggest any two methods for the disposal of solid wastes.
8. Two methods for the disposal of solid wastes
1. Sanitary landfills
2. Incineration

Question 9.
Match the columns A and B.

a) Rhizome	i) Agave
b) Bulbil	ii) Water hyacinth
c) Offset	iii) Ginger
d) Leaf buds	iv) BrvoDhvllum

Answer:

a) Rhizome	Ginger
b) Bulbil	Agave
c) Offset	Water hyacinth
d) Leaf buds	Bulbil

Question 10.
Identify the types of population growth noted in the graph as ‘A’ and ‘B’.

Answer:
a) J-shaped curve or Exponential growth
b) Sigmoid curve or Logistic growth

Question 11.
How does the inactive protoxin o£ Bacillus thurinaiensis gets converted into active toxin when an insect ingest it?
Answer:
Bt toxin protein exist as inactive protoxins but it is converted into an active form in the presence of the alkaline pH of insect gut.

Question 12.
Given below is a data showing number of individuals and dry weight of different trophic levels inva grassland ecosystem. Construct,
a) Pyramid of number
b) Pyramid of biomass
Answer:

Trophic Level	Number of individuals	Dry weight(Kg nr<sup>-2</sup>)
Primary Producer	5,842,000	809
Primary Consumer	7,08,000	37
Secondary Consumer	3,54,000	11
Tertiary Consumer	3	1.5

Answer:

Question 13.
How can you differentiate true fruits from false fruits?
Answer:
True fruits : Fruits develops only from the ovary eg. Mango
Fuse fruits : In this thalamus develops into fruit. eg. apple, strawberry, cashew, etc

Question 14.
What is biofortification? Write any two objectives of biofortification.
Answer:
biofortification
It is the breeding of crops with higher levels of vitamins minerals,proteins and healthierfats Objectives of improving nutritional quality
(i) Protein content and quality;
(ii) Oil content and quality

Question 15.
How can we make a host cell competent to receive a foreign gene or DNA?
Answer:
This is done by treating them with calcium ions and incubating the cells and recombinant DNA on ice, followed by placing them at 42°C Then putting them back on ice. This helps the bacteria to take up the recombinant DNA.

Question 16.
Early diagnosis is essential for the effective treatment of a disease. Write any two molecular diagnostic methods.
Answer:
Early diagnosis of disease is possible by:

1. Polymerase Chain Reaction (PCR) and
2.  Enzyme Linked Immuno-sorbent Assay (ELISA)

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

Question 17.
Define the following terms:
a) Autogamy
b) Geitonogamy
c) Xenogamy
Answer:
(a) Auto gamy: It is the transfer of pollen grains from the anther to the stigma of the same flower.

(b) Geitonocjamy: Transfer of palIen grains from the anther to the stigma of anotherfiower of the same plant.

(C) Xen oaamy : Transfer of pollen grains from anther to the stigma of a different plant. This type of pollination occurs betwecn genetically different species.

Question 18.
Ozone depletion in stratosphere is a serious ; environmental issue.
a) What is good ozone?
b) How do CFCs degrade ozone molecule is stratosphere?
Answer:
a) Good’ ozone- This ozone is found in the upper part of the atmosphere (stratosphere), and it acts as a shield and absorbing ultraviolet radiation from the sun.

b) The CFC produced in the upper part of the atmosphere is degraded by the action of UV. If splits and release active dorme. This active dorme destroys ozone and makes holes.

Question 19.
The following are the. diagrams of two important processes used in rDNA technology.
a) Identify A and B
b) Write the uses of A and B in rDNA technology.

Answer:
a) A – Polymerase chain reaction
B – Gel electrophoresis

b) A-Polymerase Chain Reaction is helpful to produce multiple copies (1 billion conies) òf the
gene of interest.

B- Gel electrophoresis
The cut fragments of DNA are separated by this technique.

Question 20.
Given below are examplesfor some ecological! population interactions. Place them under sUitable columns provided below.
a) Abingdon tortoise and goat.
b) Cuscuta and host tree.
c) Fig tree and wasp.
d) Algae and fungi in Lichens
e) Belanus and Chathabalus bermacles
f) Lice on humans.

Competition	Parasitism	Mutualism

Answer:

Competition	Parasitism	Mutualism
Abingdon tortoise and goat.	Cuscuta and host tree.	Fig tree and wasp.
Belanus and  Chathamalus bernacles.	Lice on humans.	Algae and fungi in Lichens.