Plus Two Botany Previous Year Question Paper March 2019

Kerala Plus Two Botany Previous Year Question Paper March 2019 with Answers

Time: 1 Hour
Cool off time : 10 Minutes
Maximum : 30 Score

General Instructions to candidates:

• There is a ‘cool off time’ of 15 minutes in addition to the writing time of 2 hrs.
• You are not allowed to write your answers nor to discuss anything with others during the ‘cool off time’.
• Use the ‘cool off time’ to get familiar with the questions and to plan your answers.
• Read questions carefully before you answering.
• All questions are compulsory and only internal choice is allowed.
• When you select a question, all the sub-questions must be answered from the same question itself.                  ,
• Calculations, figures and graphs should be shown in the answer sheet itself.
• Malayalam version of the questions is also provided.
• Give equations wherever necessary.
• Electronic devices except non programmable calculators are not allowed in the Examination Hall.

Answer All questions from 1 to 3. Each carries 1 score. (3 × 1 = 3)

Question 1.
What is the function of Restriction Endonuclease in recombinant DNA technology?
a) Linktogetherfragmentof DNA
b) Make millions of copies of DNA
c) Cut DNA into many fragments
d) Separate fragments of DNA
Answer:
Cut the DNA into many fragments

Question 2.
The government of India has introduced the concept of ……….., so as to work closely with the local communities for protecting and managing forests.
Answer:
Joint forest management (JFM)

Question 3.
Which among the following is not a greenhouse gas?
a) N₂O
b) Methane
c) Carbon dioxide
d) Ozone
Answer:
d) Ozone

Answer any 9 questions from 4 to 14. Each carries 2 scores. (9 × 2 = 18)

Question 4.
Many countries encourage the cultivation of Genetically Modified Crops (G.M. Plants). Write any two advantages of GM plants.
Answer:
Made crops more tolerant to abiotic stresses (cold, drought, salt, heat)
2 Reduce reliance on chemical pesticides (pest resistant crop)

Question 5.
Match the columns (A) and (B)

Answer:

Question 6.
Write the asexual reproductive structure given in the diagrams (a), (b), (c) and (d).

Answer:
a) zoospore
b) conidia
c) bud
d) gemmule

Question 7.
PCR and ELISA are two molecular diagnostic techniques.
a) How is PCR useful in molecular diagnosis?
b) What is the principle of ELISA?
Answer:
Early detection of disease is possible by these methods
a) PCR
i) used in the amplification of pathogenic nucleic acid.
ii) Find out cancer and other genetic diseases

b) ELISA – Antigen – antibody interaction

Question 8.
a) Identify the type of ecological pyramid given below.
b) Pyramid of energy is always upright. WHy?

Answer:
a) pyramid of biomass
b) energy decreases from one trophic level to the next or energy transfer from one trophic level to the next is 10%.

Question 9.
Deforestation is a serious issue in the present scenario. Write any two major consequences of deforestation.
Answer:

1. Leads to global warming due to excess carbon dioxide
2. Loss of biodiversity

Question 10.
Observe the flow chart given below:
a) Name the processes represented as A and B.
b) If ‘N_t’ is the population density at time t, then write down the population density equation at time t + 1.

Answer:
a) Mortality, Emigration
b) Nt + 1 = Nt + [(B + I) – (D + E)]

Question 11.
The early stages of embryo development are similar in both dicots and monocots. However, mature embryos have differences. Write two major differences between dicot embryo and monocot embryo.
Answer:

Question 12.
Given below is a flow chart showing the accumulation of DDT in different trophic levels:
a) Name the phenomenon.
b) How does it affect bird population?

Answer:
a) Biomagnification.
b) High concentrations of DDT disturb calcium metabolism in birds, which causes the thinning of eggshell and their premature breaking, causing decrease in bird populations.

Question 13.
Detritivores play a major role in decomposition.
a) What are detritivores?
b) Write an example for a detritivore.
Answer:
a) Organism which breaks up detritus into smaller particles
b) Earthworm and termite

Question 14.
Double fertilization is a characteristic feature of angiosperms.
a) Which are the events in double fertilization?
b) Name the triploid nucleus formed as a result of double fertilization.
Answer:
a) syngamy and triple fusion
b) PEN (Primary endosperm nucleus)

Answer any 3 questions from 15 to 18. Each carries 3 scores. (3 × 3 = 9)

Question 15.
Recombinant DNA technology is a complex process which involves several steps. Write down the major steps in recombinant DNA technology.
Answer:

• Isolation of the Genetic Material (DNA)
• Cutting of DNA at Specific Locations
• Amplification of Gene of Interest by using PCR
• Insertion of Recombinant DNA into the Host Cell/Organism
• Obtaining the Foreign Gene Product
• Downstream Processing

Question 16.
The discovery of Restriction Endonuclease is considered as “milestone” in the history of genetic engineering.
a) Which is the first discovered restriction endonuclease?
b) What are the criteria for naming of restriction endonuclease?
Answer:
a) Hind II

b) first capital letter – genus name
second two letters – species name
next letter – the strain of bacterium from which the restriction enzyme is isolated
last roman letter – order of isolation of enzyme

Question 17.
Observe the diagram of young anther given below.
a) Identify the parts labelled as A, B, C and D
b) Which layer nourishes the developing pollen grains?

Answer:
a) A – Epidermis
B- Endothecium
C – Middle layer
D – tapetum

b) tapetum

Question 18.
Outbreeding in animals may be outcrossing, cross- creeding and interspecific hybridisation.
a) Give an example for a progeny obtained by interspecific hybridisation.
b) How does outcrossing differs from crossbreeding?
Answer:
a) Mule

b) Out-crossing:
It is mating of animals within the same breed, but having no common ancestors on either side of their pedigree up to 4-6 generations. The offspring produced called as out-cross.

Cross-breeding:
It is the method of mating superior males of one breed with superior females of another breed.

Plus Two Botany Previous Year Question Papers and Answers