Kerala Plus Two Zoology Board Model Paper 2021 with Answers

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

Kerala Plus Two Zoology Board Model Paper 2021 with Answers

I. Answer the following questions from 1 to 31 upto a maximum score of 30.
Questions 1 to 7 carry 1 score each.

Question 1.
The cells present in the seminiferous tubules of testes that provide nutrients to the male germ cells are called ______.
Answer:
Sertoli cells

Question 2.
Voluntary termination of pregnancy before full term is called ______.
Answer:
Medical termination of pregnanacy (MTP)

Question 3.
Certain standard symbols are used in the pedigree analysis. Draw the symbols of
a) Normal male
b) Affected female
Answer:

Question 4.
Name the process ‘A’ and ‘B’

Answer:
A – DNA Replication
B – Translation

Question 5.
In Miller’s Experiment, the gases used were
a) CH₄, NH₂, H₂O, H₂
b) CH₄, NH₂, CO₂, H₂
c) CH₄, NH₂, O₂, C0
d) CH₄, NH₂, N₂, O₂
Answer:
a) CH₄, NH₂, H₂O, H₂

Question 6.
The large holes in Swiss cheese are due to the production of a large amount of CO₂, by a bacterium named ______.
a) Saccharomyces cerevisiae
b) Propionibacterium sharmanii
c) Trichodermapolysporum
d) Clostridium butylicum
Answer:
Propionibacterium sharmanii

Question 7.
Expand the following :
a) IARI
b) KVIC
Answer:
IARI- Indian Agricultural Research Institute KVIC- Khadi and Village Industries Commission

Questions 8 to 26 carry 2 scores each.

Question 8.
Complete the flow chart.

Answer:
(a)’Mammary alveoli
(b) Mammary tubule

Question 9.
Differentiate ZZ-ZW mechanism of sex determination from XX-XO mechanism.
Answer:

• ZZ – ZW type
  1. Female birds have one Z and one W chromosome, where as males have a pair of Z- chromosomes besides the autosomes.
  2. In birds the total number of chromosome is same in both males and females.
  3. Female heterogamety.
• In XO type and XY type
  1. Males produce two different types of gametes, Such types of sex determination mechanism is seen in drosophila and human male respectively.
  2. Male heterogamety.

Question 10.

a) Identify the process
b) Write the role of UTR in this process.
Answer:
(a) Translation or Protein synthesis
(b) The UTRs are present at both 5’-end and at 3’end are required for efficient translation process

Question 11.
Write any four common warning signs of drug and alcohol abuse in youth.
Answer:

1. Drop in academic performance
2. unexplained absence from school or college
3. lack of interest ¡n personal hygiene
4. deteriorating relationships with family and friends

Question 12.
a) Name the bacteria which converts milk to curd.
b) “It is essential to add a small of curd the fresh milk to get quality curd.”
Answer:
(a) Lactobacillus
(b) A small amount of curd added to the fresh milk act as an inoculum contain millions of LAB, which
at suitable temperatures multiply and convert milk to curd. It also improves the nutritional quality by increasing vitamin B₁₂

Question 13.
Observe the figure
a) Name the part labelled as ‘A’.
b) Write the functions of’A’.

Answer:
(a) Acrosome
(b) It help the sperm to enter into the cytoplasm of egg results fertilization.

Question 14.
List out FOUR ‘Evil Quartet’ which adversely affect the biodiversity.
Answer:

1. Habitat loss and fragmentation
2. Over – exploitation
3. Alien species invasions
4. Co extinctions

Question 15.
“Doctors recommended breastfeeding is inevitable in initial period of infant growth.” Do you agree with this statement? Justify your answer.
Answer:
The milk produced during the initial few days of lactation is called colostrum which contains several antibodies provide resistance for the new-born babies.

Question 16.

i.‘S’ Strain	Inject into Mice
ii. ‘R’ Strain	Mice die
iii. ‘S’ Strain (Heat Killed)	Mice live
iv. ‘S’ Strain (Heat Killed) + ‘R’ Strain (Live)	Mice live

a) Identify the experiment.
b) Why did the mice die when a mixture to heat killed ‘S’ strain and live ‘R’ strain was injected?
Answer:
(a) Griffith experiment
(b) In a mixture of heat-killed S and live R bacteria, the mice died and recovered living S bacteria from the dead mice. It is due to transforming principle transferred from the heat-killed S strain, to the R strain to synthesise a smooth polysaccharide coat and become virulent.

Question 17.
Father has ‘A’ group Mother has ‘O’ group blood. Find out the possible blood groups of their children.
Answer:
The Possible blood groups of children’s ‘A’ or O group

Question 18.

a) Identify the figure
b) What is its significance in birth control?
Answer:
(a) Tubectomy in female
(b) It is the permanent method of birth control

Question 19.
Differentiate narrowly utilitarian arguments and broadly utilitarian arguments. Give one example for each.
Answer:

Narrowly utilitarian	Broadly utilitarian
Humans get economic benefits from nature.	Biodiversity plays a major role in ecosystem services.
Eg. food, firewood, fibre, construction material, industrial products and products of medicinal importance.	Eg. Amazon forest is through photosynthesis produce 20 per cent of the total oxygen in the earth’s atmosphere.

Question 20.

a) Name the genetic disorder illustrated in this figure.
b) Redraw the amino acid sequence with normal haemoglobin.
Answer:
(a ) Sickle – cell anaemia

Question 21.
Complete the illustration showing the features of an ideal contraceptive.

Answer:
(a) User friendly
(b) Easily available
(C) Effective
(d) Reversible

Question 22.

a) Identify the figure
b) Name the part labelled as ‘P’ and write about its significance.
Answer:
(a) Blastocyst
(b) Inner cell mass – It gets differentiated into embryo.

Question 23.
Categories the following diseases under two headings
(Chlamydiasis, HIV infection, Hepatitis-B, Trichomoniasis)

Completely Curable	Non Curable

Answer:

Completely Curable	Non Curable
Chlamydiasis, Trichomoniasis	HIV infection, Hepatitis – B

Question 24.
a) Expand the term AIDS.
b) Name the causative organism.
c) Identify the diagnostic technique to detect AIDS.
d) Write any two preventive methods to avoid AIDS.
Answer:
(a) Acquired mm uno Deficiency Syndrome

(b) Human 1mm une deficiency Virus or HIV

(c) ELISA Test Enzyme Linked 1mm uno – Sorbent Assay

(d) 1. Use disposable syringe and needles.
2. Propr monitoring of blood before blood transfusion.
3. Avoid intercourse with unknown partner.

Question 25.
Fill in the blanks using the terms given below.
Answer:
(a) Opioids
(b) Papayer somniferum
(c) Hashish
(d) Cannabis sativa

Question 26.
Diagrammatic representation of the operation of Natural selection on different traits are given below.

a) Identify the figures which show stabilising and disruptive selection.
b) What is founder effect?
Answer:
(a) Figure A – Stabilising selection
Figure C – Disruptive selection

(b) The change in allele frequency in the small population from a large population leads to the evolution of new species The original drifted population becomes founders and the effect is called founder effect.

Questions 27 to 31 carries 3 scores each.

Question 27.

a) Identify the process
b) Name the parts labelled as ’A’ and ’B’.
c) Distinguish template strand and coding strand.
Answer:
(a) Transcriptional unit

(b) A – Promoter
B – Terminator

(c) Template strand – with 3-5 polarity, mRNA is produced from template strand. Coding strand Strand- with 5 ‘ 3 polarity , It does not code for anything strand.

Question 28.
a) Mention the different steps involved in test tube baby programme.
b) DifferentiateAl and IUI.
c) Write any two reasons for infertility.
Answer:
(a) In test tube baby programme, ova from the wife and sperms from the husband are collected and are induced to form zygote under simulated conditions in the laboratory.

The zygote with upto 8 blastomeres is transferred into the fallopian tube (ZIFT – zygote intra fallopian transfer) and embryos with more than 8 blastomeres, into the uterus (lUT – intra uterine transfer), to complete its further development.

(b)

AI (Artificial insemination)	lul Intra (Uterine insemination)
Semen collected from the donor isartificially into the vagina.	Semen collected from the donor is artificially into the uterus.

(c) 1. Physical or congenital problems
2. Immunological reason

Question 29.
a) Name the three layers of uterus.
b) Identify the layer which exhibits strong contractions during pregnancy.
c) Name the glandular layer that undergoes cyclical changes during menstrual cycle.
Answer:
(a) Perimetrium, Myometrium, Endometrium
(b) Myometrium
(c) Endometrium

Question 30.
a) Name the genetic disorder caused due to the presence of an additional copy of ‘X’ chromosome.
b) Write down Karyotype and mention at least two characters of that syndrome.
Answer:
(a) Klinefelter’s syndrome

(b) 44A + XXY.

• Masculine development
• Gynaecomastia

Question 31.

a) Identify the figure.
b) Distinguish Homologous and Analogous organs.
c) Comment on the evolutionary significance.
Answer:
(a) Homologous Organ

(b)

Homologous Organ	Analogous organ
Same structure with different function	Similar function but differ in structure
Represent divergent evolution	Represent convergent evolution

(c) Homologous organ represent divergent evolution. Analogous organ represent convergent evolution.