Kerala Plus Two Zoology Question Paper March 2021 with Answers

Teachers recommend solving Kerala Syllabus Plus Two Zoology Previous Year Question Papers and Answers Pdf March 2021 to improve time management during exams.

Kerala Plus Two Zoology Question Paper March 2021 with Answers

Answer the following questions from 1 to 31 upto a maximum score of 30. (7 × 1 = 7)
I. Each question from 1 to 7 carries 1 score.

Question 1.
Name the oral contraceptive for female developed by CDRI.
Answer:
Saheli

Question 2.
Name the genetic’disorder in which a blood clotting protein is affected leading to non-stop bleeding even through a simple wound.
Answer:
Haemophilia

Question 3.
Under microscope, chromatin is seen as ‘beads-on-string’ like structure. Here, ‘beads’ represent the structures called.
Answer:
Nucleosome

Question 4.
During luteal phase of menstrual cycle, Graafian follicle transforms into
Answer:
Corpus luteum

Question 5.
Organic pollutants in sewage water is measured as
(a) GMO
(b) MPT
(c) BOD
(d) HGP
Answer:
BOD

Question 6.
Select an example for homologous organs.
(a) Eyes of octopus and mammals
(b) Forelimbs of Whales and Bats
(c) Flippers of Penguins and Dolphins
(d) Wings of Birds and Butterflies
Answer:
Forelimbs of Whales and bats

Question 7.
Enzyme used in detergents for removing oily stains from laundry is _____.
(a) Lipase
(b) Protease
(c) Amylase
(d) Pectinase
Answer:
Lipase

II. Each question from 8 to 26 carry 2 scores. (19 × 2 = 38)

Question 8.
‘In a cell, euchromatin and Heterochromatin can be observed under microscope’. Distinguish between euchromatin and Heterochromatin.
Answer:

Euchromatin	Heterochromatin
i) It is loosely packed.	It is densely packed.
ii) It is Trascriptionally active.	It is Transcriptionally Inactive.

Question 9.
Presence of an additional copy of chromosome 21 was observed in a person during diagnosis.
(a) Identify the genetic disorder
(b) Write the characteristic features of this disorder.
Answer:
(a) Down’s Syndrome

(b) 1. Short stature and small round head,
2. Furrowed tongue and partially open mouth

Question 10.
Fill in the blanks to complete the table:

Micro-organism	Use of Micro-organism
i. (a) _____	Curding of Milk
ii. Bacillus thuringiensis	(b) ______
iii. Aspergillus niger	(c) ______
iv. (d) ______	Production of butyric acid

Answer:
(a) Lactic acid bacteria
(b) Control butterfly catterpillars
(c) Citric acid
(d) Clostridium butylicum

Question 11.
If a father is with ‘O’ blood group and mother is with ‘B’ blood group, write the possible blood groups of their children.
Answer:
‘B’ group and ‘O’ roup

Question 12.
Observe the figure

(a) Identify the molecular strucuture given in the figure.
(b) Name the regions labelled as A, B and C.
Answer:
(a) Antibody or Immunoglo’bulins
(b) A – Antigen binding site
B – Light chain
C – Heavy chain

Question 13.
In eukaryotes, gene expression can be regulated at several levels. Write diffèrent levels at which gene expression can be regulated.
Answer:
(i) Transcriptional level
(ii) Translational level

Question 14.
Expand the following terms related with Assisted Reproductive Technologies:
Answer:
(a) Intra Cytoplasmic Sperm Injection
(b) Gamete Intra Fallopian Transfer

Question 15.
Fill in the blanks to complete the schematic repre sentation.

Answer:
(a) Lippes loop
(b) Multiloäd 375
(c) LNG-20
(d) Progestasert

Question 16.
Write any four objectives of Reproductive and Child Health Care (RCH) programmes.
Answer:

1. Creating awareness among people about various reproduction related aspects.
2. Providing facilities and support for building up a reproductively healthy society.
3. Provide right information to the young so as to discourage children from believing in myths and
   having misconceptions about sex-related aspects.
4. Proper information about reproductive organs, adolescence and related changes, safe and hygienic sexual practices, sexually transmitted diseases.

Question 17.
‘Now-a-days, the world is facing a problem of increased rate of species extinction due to huma
activities’. Write major causes of biodiversity losses.
Answer:

1. Habitat loss and fragmentation
2. Over-exploitation
3. Alien špecies invasion
4. Co-extinctions

Question 18.
Drug/Alcohol abuse results in immediate and far reaching effects. Write some effects you have studied.
Answer:

1. Use of alcohol causes stomach ulcer and pancreatitis.
2. Causes lack of interest in personal hygiene, isolation, depression, aggressiveness etc.
3. Causes deteriorating relationship with family and friends change in eating and sleeping habit.
4. The excess usage of alcohol causes liver cirrhosis and damage to nervous system.

Question 19.
Evolution of Darwin finches in an example for ‘Adaptive radiation’.
(a) What is meant by ‘Adaptive radiation’?
(b) Give two other example for organisms those exhibitAdaptive radiation.
Answer:
(a) The process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of habitat is called adaptive radiations.

(b) Marsupia[ mammal in Australia & Placental mammals.

Question 20.
Write any four differences between Spermatogenesis and Oogenesis.
Answer:

Spermatogenesis	Oogenesis
1. Four sperms from one primary from spermatocyte.	1. It is the process of formation of ovum oregg.
2. It is the process of formation of sperms.	2. It take place in ovary.
3. It take place in male.	3. It take place in female.
4. It take place in testis.	4. Starts in embryonic stage.

Question 21.
Micrograph of Red blood cells of two persons (A) and (B) are shown below. Person B is affected with
a specific genetic disorder.
(i) Identify the genetic disorder.
(ii) Write reason for this disorder.

Answer:
(i) Sickle-cell anemia
(ii) The defect is due to substitution of glutamic acid (Glu) by valine (Val) at sixth position of beta globulin chain of haemoglobin.

Question 22.
In women, some hormones are secreted only durng pregnancy. Name any such hormones.
Answer:

1. Human chorionic gonadotropin (hCG)
2. Human placental lactogen (hPL)

Question 23.
Match following:

A	B
i. L.H. Surge	Fertilisation
ii. Leydig cells	Nutrition to
iii. Ampullary-isthmic junction	Spermatids
iv. Sertoli cells	Ovulation

Answer:

A	B
i. L.H. Surge	Ovulation
ii. Leydig cells	Androgens
iii. Ampullary-isthmic junction	Fertilisation
iv. Sertoli cells	Nutrition to Spermatids

Question 24.
“Species diversity is greater in tropical regions than in temperate regions.” Give reasons.
Answer:
Tropical environment are more constant and predictable. Solar energy is more in tropical area than temperate area.

Question 25.
Vaccines are given to children at various stages of their development.
(a) What is meant by ‘vaccine’?
(b) Write the principle of vaccination.
Answer:
(a) Vaccines are preparation of antigenic proteins of pathogen or inactivated or weakened pathogen
(b) Property of memory of the immune system

Question 26.
Match following:
Answer:

1. 1^st month – Heart sound is noticed using stethescope.
2. 2^nd month – Limbs and digits are developed in foetus
3. 5^th month – First movement of foetus is observed
4. 6^th month – Eye lids are separated and eye lashes are formed

III. Each question from 27 to 31 carries 3 scores. (5 × 3 = 15)

Question 27.
(a) Identify the equation related with genetic equilib rium given below:
p² + 2pq + q² = 1
(b) Write the factors affecting genetic equilibrium resulting in evolution.
Answer:
(a) Hardy Weinberg Equilibrium
(b) Gene flow ,Genetic drift, Mutation and Natural selection

Question 28.
LH and FSH play significant role in spermatogenesis.
(a) Write the funchons of LH and FSH in spermato genesis.
(b) Write a single term used to denote LH and FSH together.
Answer:
(a) LH – Act on the Leydig cell and stimulate t he production of and rogens
FSH – Acton Sertoli cells and stimulates some factors which help in spermatogenesis.

(b) Gonadotropins

Question 29.
Figure of ‘lac operon’ in the absence of lactose (inducer) is given below. Draw the diagram of ‘lacoperon’ in the presence of lactose and label it.

Answer:

Question 30.
SexuallyTransmitted Diseases (STDs) are seen to be high among people with age group 15 -24 yrs.
(a) Write the names of any 4 STDs
Answer:
(a)

1. AIDS
2. Genital Herpes
3. Genital Warts
4. Trichomoniasis

(b)

1. Avoid sex with unknown partner
2. Always use condoms during coitus
3. In case of doubt consult a doctor for diagnosis and treatment

Question 31.
‘Incomplete Dominance’ is an example for deviation from Mendelian Inheritance. Illustrate with example.
Answer:
It is the inheritance in which the heterozygous offspring show intermediate character between two parents. Cross given below shows the genotypic and phenbtypic ratio in F₁ and F₂ generation.