Plus Two Botany Previous Year Question Paper March 2018

Kerala Plus Two Botany Previous Year Question Paper March 2018 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.

I. (Questions 1 to 2): Answer Alt questions. Each question carries 1 score. (2 × 1 = 2)

Question 1.
Select the disease resistant variety of Bhindi produced by rotation breeding.
a) Himgiri
b) Parbhani Kranti
c) Pusa Gaurav
d) Pusa Komal
Answer:
b) Parbhani Kranti

Question 2.
Under unfavourable conditions many zooplankton species in lakes and ponds are known to enter a stage of suspended development. Name that stage.
Answer:
Diapause

II. (Questions 3 to 15) : Answer any eleven questions from the following. Each question carries 2 Scores. (Scores : 11 × 2 = 22)

Question 3.
Ozone acts as a shield for absorbing ultraviolet radiation from the sun.
a) Name the region of atmosphere where ozone is seen.
b) Write the unit used to measure ozone layer
Answer:
a) Troposphere or Stratosphere
b) Dobson

Question 4.
Match the following organisms to their life span:

Answer:

Question 5.
The DNA fragments can be separated using get electrophoresis.
a) Name the gel used in this technique.
b) Write the name of technique used to remove the DNA from the gel.
Answer:
a) Agarose
b) Elution

Question 6.
Observe the following figure:

a) Identify the figure
b) What does (i) tet^R (ii) rop (iii) ori denote?
Answer:
a) Cloning vector – pBr322
b) i) tet^R – tetracycline resistant gene
ii) rop – Gene codes for proteins involved in the replication of plasmid
iii) ori – Orgin of replication

Question 7.
Synergids have special cellular thickening at micropylar tip. Write the name and function of this structure.
Answer:

• Filiform apparatus
• It guides pollen tube into synergid

Question 8.
Controlled breeding experiments can be carried out using artificial insemination. What are the advantages of this process?
Answer:
The semen is collected from the male partner and injected into the reproductive tract of selected female. The collected semen can be stored in freezing state and used at later date.

Question 9.
Bio-fortification is a practical approach to improve the public health. Name any four such crops released by IARI.
Answer:
Vitamin A enriched carrot and spinach
Protien enriched beans – lablab

Question 10.
The products of ecosystem processes are named as ecosystem services. List out any four such services.
Answer:

1. Ecosystems purify air and water
2. Mitigate droughts and floods
3. Cycle nutrients
4. Provide wildlife habitat

Question 11.
In 1990’s Delhi ranked fourth among the most polluted cities of the world. What are the parallel steps taken to reduce vehicular pollution?
Answer:

1. Avoid the use of old vehicles
2. use of unleaded petrol
3. use of low-sulphur petrol and diesel
4. use of catalytic converters in vehicles

Question 12.
Increase in the level of green house gases leads to global warming. How can it be controlled?
Answer:
Global warming is controlled by

1. cutting down use of fossil fuel
2. improving efficiency of energy usage
3. reducing deforestation
4. planting trees

Question 13.
Genetically modified plants have been used in many ways. Give any four advantages of such plants.
Answer:

1. crops are tolerant to abiotic stresses
2. reduced reliance on chemical pesticides
3. helped to reduce post harvest losses.
4. increased efficiency of mineral usage by plants

Question 14.
In 1943 American Company Eli lilly produced human insulin artificially. Write down the method followed in this technique.
Answer:
American company Eli Lilly prepared Genetically engineered insulin. Steps are given below

1. Isolation of desired genes.
2. Insertion of desired Genes into plasmids of E. coli.
3. Introduction of plasmids into E coli cells.
4. Culture of E coli cells.
5. After this, a polypeptide chains A and B are separated and connected together by disulphide linkages.

Question 15.
Pyramid of energy is never been inverted, why?
Answer:
When energy flows from one trophic level to the next higher trophic level, energy is lost as heat. This is based on 10 % law.

III. (Questions 16 to 18) : Write any two from the following questions. Each question carries 3 Scores. (Scores : 2 × 3 = 6)

Question 16.
Meloidogyne incognitia is a nematode parasite infects the root of tobacco plants. It’s infection can be prevented by biotechnological methods.
a) Name the strategy.
b) Explain the principle behind this strategy.
Answer:
a) RNA interference

b) Nematode Meloidegyne incognitia infects the roots of tobacco plants and reduces the yield. Nematode-specific genes are introduced into the host plant by Agrobacterium vectors, it produce both sense and anti-sense RNA in the host cells that initiated RNAi and prevent the translation of the specific mRNA of the nematode.

Question 17.
The following graph shows two types of population growth curves:

a) Name the growth curves.
b) What does ‘K’ stand for?
Answer:
a) Exponential growth (J shaped growth curve)
Logistic growth (S shaped growth curve)

b) Carrying capacity

Question 18.
In Angiosperms female gametophyte is known as embryo sac. Explain it’s development.
Answer:
A single megaspore mother cell differentiates in the micropylar region of the nucellus. It undergoes meiotic division to form four megaspores.

Out of four, three degenerates and one megaspore is functional. The functional megaspore undergoes three repeated mitotic division to form 8 nucleate and 7 celled embryosac (female gametophyte).

Plus Two Botany Previous Year Question Papers and Answers