Plus Two Zoology Previous Year Question Paper Say 2018

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

General Instructions to Candidates :

  • In addition to the writing time of 1 hour, there is a 10-minute ‘cool off time’ for Botany and Zoology. Additionally, there is a five minute preparation period at the end of the Botany examination and before the start of the Zoology examination.
  • During the ‘cool off time’ and ‘preparation time’, you are not permitted to write your answers or talk with others about anything.
  • During ‘cool off time’, familiarize yourself with the questions and prepare your answers.
  • Read questions carefully before answering.
  • Only internal choice is allowed and all questions are compulsory.
  • Selecting a question means answering all the sub-questions from that question.
  • The answer sheet itself should include calculations, graphs, and figures.
  • Malayalam version of the questions is also provided.
  • Give equations wherever necessary.
  • Except for non programmable calculators, electronic devices are not allowed in the Examination Hall.

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

Question 1.
Number of spermatids produced from 25 primary spermatocyte are ………….
a) 25
b) 50
c) 100
d) 250
Answer:
c) 100

Question 2.
Study the relationship between the first two words and fill the blank space with a suitable word.
Sterilization in male: Vasectomy
Sterilization in female: ……….
Answer:
Tubectomy

Question 3.
Identify the bacterial disease from the following:
a) Typhoid
b) Amoebiasis
c) Malaria
d) Filariasis
Answer:
a) Typhoid

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

Question 4.
The incidence of STDs are reported more among the age group between 15 – 24 years.
a) What are STDs?
b) Suggest methods to prevent STDs.
Answer:
a) Sexually transmitted disease
b) i) Avoid sex with unknown partners/multiple partners.
ii) Always use condoms during coitus.

Question 5.
Observe the following cross between heterozygous dominant progeny and homozygous recessive parent. Answer the following questions.
Plus Two Zoology Previous Year Question Paper Say 2018, 1
a) Identify the cross.
b) Mention the significance of this cross.
Answer:
a) Test cross
b) In a testcross genotype of F1 can be determined when it is crossed with recessive parent.

Question 6.
Following diagram shows amino acid sequences of a part of β chain of Haemoglobin of two individuals. Observe the amino acid sequence and answer the following questions:
Plus Two Zoology Previous Year Question Paper Say 2018, 2
a) Which among the above indicates sickle cell anaemic condition?
b) Justify your answer.
c) Describe what is single base substitution.
Answer:
a) Second amino acid chain.
b) The defect is caused by the substitution of Glutamic acid by Valine at the sixth position of the beta globin chain of the haemoglobin molecule.
c) It is due to the single base substitution at the sixth codon of the beta globin gene from GAG to GUG.

Question 7.
“Human genome project is a mega project”. Give two reasons to explain this.
Answer:

  1. Determine the sequences of the 3 billion chemical base pairs.
  2. Store this information in database.
  3. Determine the sequences of the 3 billion chemical base pairs.

Question 8.
Observe the diagram and answer the following questions:
Plus Two Zoology Previous Year Question Paper Say 2018, 3
a) Identify the diagram.
b) Name the enzymes A, B and C.
Answer:
a) Lacoperon
b) A – beta galactosidase
B – Permease
C – Tranacetylase

Question 9.
In sewage treatment plants microbes play a significant role. Distinguish between primary and secondary treatment in sewage plants.
Answer:
Primary treatment: It is the removal of large and small particles from the sewage through filtration and sedimentation.

Secondary treatment: The primary effluent is passed into large aeration tanks that is agitated and air is pumped into it. It results the vigorous growth of useful aerobic microbes into floes.

Question 10.
Human beings can conserve and protect our eco-system and biodiversity. Prepare a handout to show different methods of Biodiversity conservation.
Answer:
In situ conservation:
Some areas are considered as ‘biodiversity hotspots’ that shows high species richness and high degree of endemism. So organisms are conserved in their natural habitat.

Ex situ Conservation:
It is the conservation of threatened animals and plants outside their natural habitat.

Question 11.
“Genetic code is universal in nature”.
a) Substantiate this statement.
b) Mention any two other salient features of genetic code.
Answer:
a) From bacteria to human being triplet codon code for the same amino acid.

b) i) The codon is triplet.
ii) One codon codes for only one amino acid, it is unambiguous.
iii) Some amino acids are coded by more than one codon, It is degenerate.
iv) The codon is read in mRNA in a contiguous fashion. There are no punctuations.

Question 12.
p2 + 2pq + q2 = 1 is the gene frequency of a popula¬tion showing an evolutionary priciple.
a) Name the principle
b) Enlist any three factors affecting this principle.
Answer:
a) Hardy weinberg principle.
b) Gene migration, Genetic drif, Mutation and Natural selection.

Question 13.
The blood group of a child is ‘O’. His father is with ‘A’ blood group and mother with ‘B’ blood group. Write down the genotype of the child and genotypes of parents.
Answer:
The genotype of child is O group
Father IA i
Mother IB i

Question 14.
Plus Two Zoology Previous Year Question Paper Say 2018, 4
Above homologous organs provide evidence for a particular type of evolution.
a) Identify the type of evolution.
b) What do you mean by homologous organs?
Answer:
a) Divergent evolution
b) Homologous organ – same structure but different function.

(Q. 15 to 18). Answer any three. Each carries 3 scores. (3 × 3 = 9)

Question 15.
Match the columns B & C with column A.

A B C
Ovulation Endometrium LH
Implantation Uterus Progesterone
Gestation Graafian follicle HCG

Answer:

A B C
Ovulation Graafian follicle LH
Implantation Endometrium progesterone
Gestation Uterus HCG

Question 16.
Prepare a flowchart of evolution of man in descending order by choosing the names given below:
Homo sapiens, Homo erectus, Homo habilis, Australopithecines, Ramapithicus, Neanderthal
Answer:
Ramapithecus → Australopithecus → homo habilus → homo erectus → neanderthal man → Homo sapiens.

Question 17.
Classify the following barriers of innate immunity under three suitable headings:
Skin, Saliva, WBC, Monocyte, Mucus, Acid of stomach
Answer:
Physical barrier – skin and mucus
Physiological barrier – acid in stomach and saliva
Cellular barrier – WBC, Monocyte

Question 18.
Expand the following:
1) SNP
2) BAC
3) YAC
Answer:
1) SNP Single nucleotide polymorphism
2) BAC Bacterial artificial chromosome
3) YAC Yeast artificial chromosome

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