2020 SAY (+2)
PART A: BOTANY
Answer any 3 questions from 1 – 5. Each carries 1 score. (3 x 1 = 3)
1. Choose the correct answer:
The pioneer species in xerarch succession is:
(a)
Phytoplankton
(b)
Lichen
(c)
Zooplankton
(d)
Bryophyte
2. Choose the correct answer:
An organism that has the ability to concentrate its urine is:
(a)
Desert Lizard
(b)
Seal
(c)
Flamingo
(d)
Kangaroo rat
3. Observe the relationship between the
first two terms and fill in the blank:
Endothecium: Protection;
Tapetum: ......................
4. Observe the figure given below and
identify the type of age pyramid for human population:
5. Fill in the blank:
Alpha I-antitrypsin is used to treat the disease ...................
Answer any 9 questions from 6 – 16.
Each carries 2 scores. (9 x 2 = 18)
6. One of the effects of water
pollution is algal bloom.
(a)
Define algal bloom.
(b)
Write two effects of algal bloom in
aquatic ecosystem.
7. Notice the organisms given below:
Leech,
Cockroach, Dog, Earthworm
(a)
Choose hermaphrodite organism from
the above.
(b)
Define hermaphrodite.
8. Write the uses of scrubber and
electrostatic precipitator.
9. Match the items of column A with B.
|
A |
B |
|
(a)
Ginger |
I.
Bulbil |
|
(b)
Water hyacinth |
II.
Leaf bud |
|
(c)
Agave |
III.
Tuber |
|
(d)
Bryophyllum |
IV.
Rhizome |
|
|
V.
Offset |
10.
Observe the figure given below:
Fill in the blanks a, b, c, d in the figure. (Hint: a, b, c –
stages, d – enzyme).
11.
Flowers are classified into
Chasmogamous and Cleistogamous flowers.
(a)
Cleistogamous flowers are
autogamous. Justify.
(b)
Define autogamy.
12.
EcoRI is a restriction endonuclease.
What do E, Co, R, I represent?
13.
The concentration of toxicants like
DDT increase in successive trophic levels.
(a)
Name this phenomenon.
(b)
How does this phenomenon affect the fish-eating
birds in an aquatic food chain?
14.
Expand GEAC and ADA.
15.
Observe the figure given below:
(a)
Identify the parts a, b, c.
(b)
Write the functions of c.
16.
Bt cotton contains cry genes from a
bacterium.
(a)
Name that bacterium
(b)
Give two examples for cry genes.
Answer any 3 questions from 17 – 20.
Each carries 3 scores. (3 x 3 = 9)
17.
There are five main steps in
breeding a new genetic variety of a crop.
(a)
Write that five steps.
(b)
Name a semi-dwarf variety of wheat
produced in India.
18.
Analyse the following table showing
population interaction:
|
Species A |
Species B |
Name of
interaction |
|
+ |
(i) |
Commensalism |
|
+ |
+ |
(ii) |
(a)
Identify (i) and (ii).
(b)
Define (ii).
(c)
Give an example of commensalism.
19.
A typical angiosperm embryo sac is
8-nucleate and 7-celled.
(a)
Name the cells that constitute egg
apparatus.
(b)
Explain monosporic type of embryo
sac development.
20.
Decomposition has five important
steps.
(a)
Write that five steps.
(b)
Give an example of a detritivore.