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Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 4 Molecular Basis of Inheritance.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 4 Molecular Basis of Inheritance

Question 1.
Observe the diagram below: (MAY-2010)

Which among the following is the complimentary sequence of the DNA fragment shown above?
a) 5′ -> ATTCG -> 3′
b) 3′ -> ATTCG -> 5′
c) 3′ -> TAAGC -> 5′
d) 3′ -> CGAAT -> 5′
Answer:
3′ -> TAAGC -> 5′

Question 2.
DNA sequence is provided below:   (MAY-2010)
TACGAGTTATATATACAT
a) Write down the triplet codon- it codes for.
b) If a nitrogen base is added in between 4th & 5th nitrogen bases, what will be its effect on transcription?
Answer:
a) AUG / CUC / AAU / AUA / UAU / GUA
OR
TAC / GAG / TTA / TAT / ATA / CAT
b) Frame shift mutation / point mutation/Mutation / Entire amino acid sequence changed / incorrect protein produced / change in protein structure / incorrect transcription and translation /abnormal protein.

Question 3.
In a paternity dispute, the VNTR DNA samples of parent and child were DNA finger printed. The diagrammatic representation of the DNA fingerprint is shown below.  (MAY-2010)

a) What is your opinion about the paternity of child? Substantiate your opinion.
b) List down any four major steps of molecular biological procedures adopted for this.
Answer:
a) Paternity is confirmed
VNTR bands / finger print bands / bands are similar.
b) Steps of DNA finger printing techniques are
i) Isolation of DNA
ii) Digestion of DNA by restriction endo nuclease
iii) Seperation of DNA fragment by Electrophoresis,
iv) Plotting of DNA fragment into Nitro cellulose
v) Ditection of hybridised DNA by Auto radiography

Question 4.
A transcriptional unit is given below. Observe it and answer the questions.  (MARCH-2012)

a) How can you identify the coding strand?
b) Write the sequence of RNA formed from this unit?
c) What would happen if both strands of the DNA act as templates for transcription?
Answer:
a) Coding strand has 5′ end at the promoter or 5’TCAGTACA3′
b) 5′ UCAGUACA 3′
c) The two RNA will be complimentary and may form double stranded RNA and it prevents the translation.

Question 5.
In E.coli lactose catabolism is controlled by Lac operon. Lac operon in the absence of inducer (lactose) is given below. (MARCH-2012)

a) What is ‘P’?
b) Name the enzymes produced by the structural genes ‘Z’, ‘Y’ and ‘a’?
c) Redraw the diagram in the presence of an inducer.
Answer:
a) Promoter
Z-Bgalactosidase
b) Y – Permease
a-Transacetylase
c)

Question 6.
Following are the first two steps in Griffith transformation experiment: (MAY-2012)
1) S strain 2 Inject into mice 2 mice live
2) R strain 2 Inject into mice 2 mice die
a) If there is any mistake correct it.
b) Write the remaining steps.
Answer:
a) 1. S strain -> inject into mice -> mice die
2. R strain inject into mice -> mice live
b) When Griffith was injected heat-killed S strain into mice, bacteria did not kill them. But he injected a mixture of heat-killed S and live R bacteria, the mice died .

Question 7.
DNA is better genetic material than RNA. Do you agree with this statement ? Substantiate. (MAY-2012)
Answer:
The 2-OH group present at the nucleotide in RNA is a reactive group and makes RNA labile and easily degradable. Hence DNA is less reactive and structurally more stable when compared to RNA. Therefore, among the two nucleic acids, the DNA is a better genetic material.

Question 8.
Given below is the diagrammatic representation of first stage of a process in bacteria. (MAY-2012)

a) Identify the process.
b) Name the enzyme catalyses this process.
c) What are the additional complexities in Eukaryotes for this process?
Answer:
a) Prokaryotic transcription
b) RNA polymerase
c) In eukaryotes hnRNA undergo additional processing called as splicing, capping and tailing.
In splicing the introns are removed and exons are joined together. In capping methyl guanosine triphosphate is added to the 5-end of hnRNA. In tailing, adenylate residues are added at 3-end in a template.The fully processed hnRNA, called as mRNA, that is transported out of the nucleus for translation.

Question 9.
The flow of genetic information is shown below. (MARCH-2013)

Name the processes a, b, c
Answer:
a) Replication
b) Transcription
c) Translation
d) Reverse transcription

Question 10.
RNA is not an ideal molecule as genetic material because ________. (MARCH-2013)
a) 2’OH group of ribose is reactive and make it labile
b) It is catalytic and hence reactive
c) Both (a) and (b)
d) None of the above
Answer:
c) Both a and b

Question 11.
Presence of lactose enhances the production of (3 galactosidase and other enzymes in bacteria, how will you explain this phenomenon? (MAY-2013)
Answer:
In lac operon,lactose is the inducer.Inducer binds with repressor protein but repressor cannot bind to op-erator gene,the free operator gene induces the RNA polymerase to bind with promoter and initiates tran-scription Three structural genes synthesise three mRNAs to produce enzymes.

Question 12.
A DNA sequence needed for coding a peptide is given below. (MAY-2013)
CAAGTAAATTGAGGACTC
(Hint: Codons and Aminoacids)
CAAGTAAATTGAGGACTC
UUA-Leu
CCU – Pro
CAU – His
ACU-Thr
GUU-Val
GAG-Glu
a) Write the complementary mRNA coding sequence for this.
b) Find out the amonoacid sequence of the peptide chain using the codons given in the hints.
c) If a mutation cause a change in the sixth codon CTC to CAC. It leads to a mendelian disorder. Identify the disease and write the specific characteristics of the diseasie.
Answer:
a) GUUCAUUUAACUCCUGAG
b) Val,His,Leu,Thr,Pro,Glu
c) Sickle cell anaemia, RBC become sickle shaped and unable to take oxygen .These are destroyed more rapidly leading to anaemia.

Question 13.
Draw a flow chart showing the steps of southern blot hybridization using radio labelled VNTR. (MAY-2013)
Answer:

Question 14.
“Prediction of the sequence of amino acids from the nucleotide sequence in mRNA is very easy, but the exact prediction of the nucleotide sequence in m RNA from the sequence of amino aids coded by mRNA is difficult”.(MARCH-2014)
a) Which properties of the genetic code is the reason for the above condition? Explain.
b) Which are the stop codons in DNA replication?
Answer:
a) Degeneracy – A single aminoacid is represented by many codons (degenerate codons)
b) Stop codons are UAA,UAG,UGA

Question 15.
Diagrammatic representation of Central dogma’ is given below: Observe the diagram carefully and redraw it making appropriate corrections. (MARCH-2014)

Answer:

Question 16.
Explain the phenomenon shown in the following figure and the reason for difference in the production of  II recombinants in Cross A and Cross B as explained by morgan. (MARCH-2014)

Difference in chromosome number of some human beings A, B. C and D are given below:
A) 22 pairs of Autosomes
B) 22 pairs of Autosomes+XO
C) 22 pairs of Autosomes + 1 Autosome
D) 22 pairs of Autosomes+XXY
OR
a) Identify the person who suffers from Klinefelter’s syndrome. Write its symptoms.
b) Differentiate between aneuploidy and polyploidy.
Answer:
The percentage of cross over depends upon the distance between the genes.
The genes are closer in cross A,so the less number of recombinants are produced. This is called link-age.
In cross B, genes are distantly located so more number of recombinants are produced.
OR
a) 22 pairs of autosomes+XXY, Sterile male, poorly developed testis and mental retardation
b) Aneuploidy-failure of separation of chromosomes during cell division results in-the gain or loss of chromosome.
Polyploidy – Failure of cytokinesis aftertelophase results in the increase in a whole set of chromosome

Question 17.
Correct the amino acid sequence of sickle cell haemoglobin. (MAY-2014)

Answer:

Question 18.
Diagram of components of DNA are given below: Identify and differentiate the two diagrams I and II. (MAY-2014)

Answer:
I- Nucleotide II- Nucleoside

Question 19.
a) Identify the diagram and explain. (MAY-2014)

b) In same cases DNA is produced from RNA. Name this process and give example.
Answer:
a) Central Dogma in molecular biology
b) Reverse transcription

Question 20.
a) Define mutation. (MAY-2014)
b) What are the different types of mutation?
Answer:
a) Mutation is a phenomenon which results in alteration of DNA sequences and consequently results in changes in the genotype and the phenotype of an organism
b) physical mutation and chemical mutation

Question 21.
a) Paternity or maternity can be determined by certain scientific methods. What is it? Define. (MAY-2014)
b) Briefly write the* methodology involved in the technique.
c) Comment on its other applications.
Answer:
a) DNA fingerprinting. DNA fingerprinting involves identifying differences in some specific regions in DNA sequence
b) i) isolation of DNA
ii) digestion of DNA by restriction endonucleases
iii) separation of DNA fragments by electrophoresis
iv) transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon
v) hybridisation using labelled VNTR probe
vi) detection of hybridised DNA fragments by autoradiography
c) It is also used in forensic science

Question 22.
Fill in the blanks: (MARCH-2015)
a) _________is a metabolic disorder that occurs due to the lack of an enzyme, that converts phenylalanine to tyrosine.
b) _______is a disease caused by the substitution of Glutamic acid by valine at 6th position.

Answer:
a) Phenylketonuria
b) Sickle-cell anaemia

Question 23.
The flow of genetic information is shown below. Name the process of (a) and (b). (MARCH-2015)

Answer:
a) Trancription
b) Translation

Question 24.
Explain transcription. A transcription unit in DNA is defined primarily by three regions. Write the names of any two regions. (MARCH-2015)
Answer:
Information contained in DNA is copied down to mRNA is called Transcription – Promoter and structural gene.

Question 25.
Observe the diagram and answer the questions: (MAY-2015)

a) What is the difference in the replication processes in A strand and B strand?
b) What is the role of DNA ligase in the replication process in B strand?
c) What is meant by Replication fork?
Answer:
a) In A, replication is continuous and form leading strand but in B replication is discontinuous and form lagging strand.
b) In B, short stretch of Okazaki fragments are connected with the help of DNA ligase and form continuous strand
c) The replication occur within a small opening of the DNA helix, referred to as replication fork. It appears as Y shaped forked structure.

Question 26.
Observe the following diagram and answer the questions: (MAY-2015)

a) Diagrammatically represent the changes take place when lactose is added to the medium.
b) What is the role of z, y and a genes in this metabolic pathway?
Answer:
a)

b) The z gene codes for beta-galactosidase which is responsible for the hydrolysis of the disaccharide, lactose into galactose and glucose. The y gene codes for permease, which increases permeability of the cell to beta-galactosides.The a gene encodes a transacetylase

Question 27.
Read carefully the sequence of codons in the mRNA unit and answer the questions. (MARCH-2016)

a) What change in needed in the first codon to start the translation process?
b) If translation starts by that change, till which codon it can continuous? Why?
Answer:
a) AUG is needed
b) UGA, Termination of translation occurs

Question 28.
Schematic representation of DNA fingerprints are shown below: (MARCH-2016)

[Hints : C is a sample taken from a crime scene, A and B from two suspected individuals]
a) Which one of the suspected individual may involved in the crime?
b) Write any other use of DNA fingerprinting.
Answer:
a) suspected person is B
b) disputed parentage determining population and genetic diversities.

Question 29.
Observe the figure of mRNA and answer the questions: (MAY-2016)

a) Find the start and stop codons.
b) How many amino acids will be present in the protein translated from this mRNA?
c) The additional sequences that are not translated in mRNA are called _______.
Answer:
a) Start codon – AUG
Stop codon – UAG
b) 4
UTR- Untranslated region

Question 30.
a) The hints of the lac operon is given below: (MAY-2016)
Hints:
Inducer, Repressor,
Structural genes, operator Regulatory gene
i) Which substance is acting as inducer in this operon?
ii) Explain the working of operon in presence of the inducer.
OR
b) With the help of the figure given, explain the processing of hnRNA to mRNA in eukaryotes.

Answer:
a) i) lactose inducer
ii) If lactose is present in a medium, it has to be breakdown into glucose and galactose,for this positive control of operon works and structural genes transcribe. The switch on condition of operator gene is due to the binding of RNA polymerase with promotersite. In +ve control, repressor from regulator gene is inactivated due to the presence of lactose.
OR
b) 1) Splicing-the introns are removed and exons are joined together.
2) capping -methyl guanosine triphosphate is added to the 5-end of hnRNA.
3) Tailing- adenylate residues (200-300) are added at 3-end in a template
After these three process, fully processed mRNA is released from nucleus into cytoplasm for protein synthesis.

Question 31.
Examine the following fragment of beta globin chain in human haemoglobin and identify the hereditary disease with reason. (MARCH-2017)

Answer:
Sickle cell anaemia
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 The mutant haemoglobin molecule under low oxygen tension causing the change in the shape of the RBC from biconcave disc to elongated sickle like structure.

Question 32.
Which of the following combinations do not apply to DNA? (MARCH-2017)
a) Deoxyribose, Guanine
b) Ribose, Adenine
c) Deoxyribose, Uracil
d) Guanine, Thymine
1) (a) and (b)
2) (b) and (c)
3) (c) and (d)
4) (a) and (d)
Answer:
2) b) and c)

Question 33.
Examine the diagram of mRNA given below. Mark the ‘5’ and ‘3’ ends of the mRNA by giving reasons. (MARCH-2017)

Answer:
Polyadynilation always at 3′ end of m RNA ,so the other must be 5′ end.

Question 34.
A small fragment of skin of a different person was extracted from the nails of a murdered person. This fragment of skin led the crime investigators to the murderer. Based on this incident answer the following questions: (MARCH-2017)
1) What technique was used by the investigators?
2) What is the procedure involved in this technique?
OR
In an E. coli culture lactose is used as food instead of glucose. If so, answer the following questions:
1) How do the bacteria respond to the above situation at genetic level?
2) If lactose is removed from the medium what will happen?
Answer:
1) DNA finger printing
2) The technique, is based on following procedure
i) isolation of DNA,
ii) digestion of DNA by restriction endonucleases,
iii) separation of DNA fragments by electrophoresis,
iv) transferring (blotting) of separated DNA fragments to synthetic membranes, such as nitrocellulose or nylon,
v) hybridisation using labelled VNTR probe, and vi) detection of hybridised DNA fragments by autoradiography
OR
In this closely associated genes function as unit called operon If lactose is present in a medium, it has to be breakdown into glucose and galactose ,for this positive control of operon works and structural genes transcribe with the help of switch on condition of operator gene. This is due to binding of RNA polymerase on promoter site of DNA.

Question 35.
Find the odd one and write the common feature of others. (MAY-2017)
Cytidine, Adenine, Thymine, Guanine.
Answer:
Cytidine, All others are nitrogen bases.

Question 36.
Observe the diagram:  (MAY-2017)

a) Redraw the diagram correctly if any mistake is there.
b) What does the diagram indicate?
c) What is the function of DNA ligase in this process?
Answer:
a)

b) Replication fork.
c) Discontinuously synthesised fragments of DNA are joined by DNA ligase.

Question 37.
Read the codon sequence in the mRNA unit which is undergoing translation.  (MAY-2017)

a) What will happen if the nitrogen base ‘U’ in the sixth position is replaced by ‘A’ by point mutation?
b) Name and define this type of mutation.
c) Draw the base sequence in the coding DNA strand from which the above mRNA is transcribed.
Answer:
a) Translation stop as UAA is a stop codon.
b) In this point mutation one nitrogen base is deleted.
c)

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 3 Principles of Inheritance and Variation.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 3 Principles of Inheritance and Variation

Question 1.
Polypeptide chains of two haemoglobin molecules are shown below. One of the chains shows an abnormality. Observe the diagram and answer the following questions. (MARCH-2010)

a) Which of the polypeptide chain in haemoglobin is abnormal leading to a disease?
b) What is the reason for this abnormality?
c) What will be the effect of this change in polypeptide chain?
Answer:
a) A
b) Substitution of glutamic acid by valine in the 6th position of polypeptide chain.
c) The RBC become sickle shaped causing a disease sickle cell anaemia / Affect the o₂ carrying capacity of RBC.

Question 2.
To find out the unknown genotype of a violet flowered pea plant a researcher done the following cross. Observe the diagram and answer the following questions: (Hint: Violet flower colourin pea plant is dominant over white). (MARCH-2010)

a) What would be the above cross called?
b) Can you determine the unknown genotype of violet flowered parent by drawing Punnet square?
Answer:
a) Test cross
b)

Genotype of unknown parent Ww/ Heterozygous.

Question 3.
Some genetic abnormalities, their genotypes and features are distributed in columns A, B and C respectively. Match them correctly. (MAY-2010)

Answer:

Question 4.
The flow charts A and B given below represents the inheritance of normal haemoglobin and sickle cell haemoglobin: (MAY-2010)

a) Observe flow chart A and complete the flow chart B.
b) Note down the genotype of a sickel cell anaemia patient and mention the symptom of the disease.
c) Mention the peculiarity of Hb^A Hb^s phenotype.

Answer:
a)

b) Sickle cell Anemia genotype is homozygous for Hb^s (Hb^sHb^s).
Symptoms
SevereAnemia
Oxygen shortage etc.
Haemoglobin becomes sickle shaped.
c) Hb^A Hb^s indicate heterozygous individuals, who are the carrier of sickle cell Anemia, but unaffected ones.

Question 5.
After analyzing’the karyotype of a short statured round headed person with mental retardation, a general physician noticed an addition of autosomal chromosome. (MARCH-2011)
Answer the following questions.
a) Addition or deletion of chromosome generally results in ______
b) What may be the possible syndrome or disorder of the above person should suspected to be?
c) Suggest two / more morphological peculiarities to confirm the chromosome disorder in that person.
Answer:
a) Aneuploidy / Chromosomal disorders/ Chromo-somal abberrations/Chromosomal mutations.
b) Down’s syndrome / Mongolism / Trisomy 21st / 45A + xx / xy.
c) Furrowed tongue, partially opened mouth, Broad palm, Skin fold at the corner of the eye.
Two correct points.

Question 6.
The frequency of occurrence of Royal disease or . haemophilia is high in the pedigree of royal families of Queen Victoria. Which of the following cannot be generally inferred from this? (MARCH-2011)
a) Queen Victoria was not homozygous forthe disease.
b) Many heterozygous females were there in the Royal families.
c) Non-Royal families were not affected with haemophilia.
d) There is less possibility to become a female diseased.
e) Generally a diseased female cannot survive after the first menstruation.
f) Pedigreee analysis is the study of inheritance patterns of traits in human females.
Answer:
‘C’ and ‘f ’ c₁ non royal families were not affected with haemophilia.
f₂ Pedegree analysis is the study of inheritance pattern of traits in human females.

Question 7.
A couple have two daughters. The blood group of husband and wife is ‘O’ (MARCH-2011)
a) What is the possible blood groups of the children should have?
b) Whether any change in blood group will occur if they have two sons instead of daughters.
Substantiate your answer.
Answer:
a) O group
b) No.
There is no sex specificity in blood group alleles / Co-dominance / Homozygous recessive. Not related to sex chromosomes or autosomes /

Question 8.
Complete the table using suitable terms. (MARCH-2012)
Turner’s syndrome (a) ______ Sterile female
(b) __________44A + XXY (c) _________
(d) __________ Trisomy 21 Mental retardation
Answer:
a) 44A + X0
b) Klinefelters Syndrome
c) Sterile male
d) Down’s Syndrom

Question 9.
In pea plant the gene for yellow seed colour is dominant over green and round seed shape is dominant over wrinkled. Write the four types of gametes formed in a heterozygous pea plant with yellow and round seeds. (Yy Rr).
Answer:
YR Yr yR yr

Question 10.
The first child of a couple is affected with phenylketonuria. During the second pregnancy they visited a genetic counsellor and he prepared a pedigree chart of their family. (MARCH-2012)
a) What is pedigree analysis?
b) Draw the symbols for
i) Affected female.
ii) Sex unspecified.
iii) Consanguineous mating.
Answer:
a) It is the study of inheritance of a trait for several generation of a family.
b)

Question 11.
Diagrammatic representation of chromosome map of Drosophila is given below: (MARCH-2012)

Y – Yellow
W – White
M – Miniature
a) Which genes are more linked?
b) Who mapped the chromosome firstly?
c) Tightly linked genes show low recombination. Why?
Answer:
a) y and w
b) Alfred Sturtevant
c) Crossing over rarely takes between genes

Question 12.
Work of a student is given below:  (MAY-2012)

a) From the above give an example for genotype and phenotype.
b) Complete the work’using punnett square and find out the phenotypic ratio in the F2 generation.
Answer:
a) First filial generation Genotype-RrYy,Phenotype- round yellow

Question 13.
Identify the traits from the pedigree chart. Give one example each.  (MAY-2012)

Answer:
a) Autosomal dominant trait
Eg. Muscular dystrophy
b) Autosomal recessive trait
Eg. Sickle cell anaemia

Question 14.
A poultry farm manager was cursing his hens for producting lion share of cocks in its progeny. Hearing this, Kumar – farm attender starts to blame his wife for delivering consecutive girl children. Analyze the situtations scientifically and state whether you agree with kumar.  (MARCH-2013)
Answer:
No, During spermatogenesis two types of gametes are produced of which 50 per cent carry the X- chromosome and the rest 50 per cent has Y- chromosome besides the autosomes. Females produce only one type of ovum with an X- chromosome.
In case the ovum fertilises with a sperm carrying X- chromosome the zygote develops into a female (XX) and with Y-chromosome results into a male offspring. Thus the genetic makeup of the sperm that determines the sex of the child.

Question 15.
In the given pedigree the shaded figures denote individuals expressing a specific trait. (MARCH-2013)

Which of the following is the most probable mode of inheritance of this trait.
Answer:
Principles of inheritance & Variation
A – Simple Mendelian Recessive
B – Co dominant relationship of a single pair of alleles.
C- X – linked recessive transmission
D – X- linked dominant transmission
E – Polygenic inheritance.
X-Linked recessive transmission

Question 16.
“Gopalan argues that if father is of A’ blood group, mother is of ‘B’ blood group. Their children can only be A’ group, B group or AB’ group.” (MARCH-2014)
a) Do you agree with Gopalan’s Argument ?
b) Give reason for your answer.
Answer:
a) No ,All groups are possible including O group
b) 

Question 17.
Identify the syndrome from the genotype given below: (MAY-2014)
1) 44 Autosomes + XXY
2) 44 Autosomes + XO
Answer:
1) Klinefelters syndrome
2) Turners syndrome

Question 18.
The family of Queen Victoria shows a number of haemophilic descendants as she was the carrier of the disease. Name the pattern of inheritance of this royal disease. (MAY-2014)
Answer:
Sex linked inheritance .
The heterozygous female (carrier) for haemophilia may transmit the disease to sons.
(Criss cross inheritance)

Question 19.

a) Identify the syndrome from the diagram, and write the genotype. (MARCH-2015)
b) It occurs in both sexes (male and female)? Write the reason.
Answer:
a) Downs syndrome , 45 A+XX or 45A+XY
b) The cause of this genetic disorder is the presence of an additional copy of the chromosome number 21 (trisomy of 21).

Question 20.
It is evident that, it is the genetic make up of the sperm that determine the sex of the child in human beings. Substantiate. (MARCH-2015)
Answer:
During spermatogenesis among males, two types of gametes are produced. 50% of the total sperm produced carry the X-chromosome and the rest 50 per cent has Y-chromosome besides the autosomes. In case the ovum fertilises with a sperm carrying X- chromosome the zygote develops into a female (XX) and the fertilisation of ovum with Y-chromosome carrying sperm results into a male offspring. Hence the genetic makeup of the sperm that determines the sex of the child.

Question 21.
Diagrammatic representation of the pedigree analysis of the inheritance of sickle cell anaemia is shown below: (MAY-2015)

a) Name the type of inheritance shown in the figure.
b) Write the genotype of A and B.
(Hint: Disease is controlled by a pair of alleles Hb^A & Hb^s)
Represent pedigree analysis of an X-linked recessive inheritance diagrammatically.
Answer:
a) Mendalian inheritance
b) A-Hb^A Hb^s B- Hb^A Hb^s

Question 22.
Observe the inheritance shown in A (MAY-2015)

a) Name the type of inheritance shown in A and B.
b) What is the difference between the two types of inheritance.?
Answer:
a) A- Dominance B-Co dominance
b) In dominance , dominant gene mask the expression of recessive gene and tall character in F₁ progenies but in co dominance both dominant gene express together and shows AB blood group.

Question 23.
Results of a famous experiment is given in the figure. Answer the questions. (MARCH-2016)

a) Identify the experiment.
b) Which property of the DNA is proved by this experiment?
Answer:
a) Semiconservative DNA replication experiment
b) During DNA replication one parent strand is conserved

Question 24.
Which of the following is not a Mendelian disorder? (MARCH-2016)
i) Colourblindess
ii) Down’s syndrome
iii) Haemophilia
iv) Thalassemia
Answer:
ii) Down’s syndrome

Question 25.
Study the following cross and answer the questions. (MARCH-2016)

[Hint: ABO blood group in man is controlled by three alleles I^A, I^B, and i]

a) Write the geno types of Father, Mother and Son.
b) The type of dominance of human blood group inheritance is ________.
Answer:
Father-I_A i or i i Mother-I_B or i i Son-i i

Question 26.
Observe the figures and answer the questions. (MARCH-2016)

a) Identify the syndromes A and B.
b) What is the chromosome numbers in A and B?
Answer:
a) A-KlinefelterSyndrome;
B- Turner’s Syndrome
b) A-47 B-45

Question 27.
a) Complete the flow chart of chromosomal disorder by filling the blank boxes (A and B). (MAY-2016)

b) What is an euploidy?
Answer:
a) A-monosomy of sex chromosome B – Klinefelters syndrome
b) Failure of separation of homologous chromosomes during anaphase I of meosis lead to gain or loss of chromosome, it is called aneupoidy.

Question 28.
Observe the figure below and answer the questions following: (MAY-2016)

a) Identify the figure
b) What shows the shaded symbols used?
Answer:
a) Pedigree analysis or Autosomal dominant trait
b) Individuals with genetic disorder (male and female)

Question 29.
The following table shows the F₂ generation of a dihybrid cross, identify the ‘Phenotype’ with homozygous recessive genotype.(MARCH-2017)
Find out A : B : C : D.

Answer:
B , Genotype A: B:C:D: = 3:1:9:3 OR 9:3:3:1

Question 30.
Which of the following do not have similar sex chromosomes? (Homogametic) (MARCH-2017)
a) Human female
b) Drosophila female
c) Bird female
d) Bird male
Answer:
c) Bird female

Question 31.
Observe the following diagram and answer the questions: (Hint: Steps in making a cross in pea plant) (MAY-2017)

a) Name the process marked as A and write its significance.
b) Diagrammatically represent a monohybrid cross between Tall and dwarf pea plants.
Answer:
a) Removal of anthers from female plants
Significance –It prevents self pollination and fertilization

Question 32.
Observe the diagrammatic representation of the following pedigree analysis and answer the questions (MAY-2017)
a) Describe the type of inheritance shown in the diagram.
b) Distinguish between Mendelian disorder and chromosomal disorder with example.

Answer:
a) Sex linked inheritance
b) Mendelian disorder is determined by mutation in the single gene.
These disorders are transmitted to off springs in the same line as the principles of inheritance.

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 2 Reproductive Health.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 2 Reproductive Health

Question 1.
Diagram shown below is a surgical method used for female sterilization. (MARCH-2010)
a) What is the method shown in diagram?
b) Mention any two Intra uterine devices to prevent conception.
c) What is the surgical method of male sterilization called?

Answer:
a) Tubectomy
b) Any two methods (Cu-T, Cu-7, loop, Multibad-375, Hormone producing progestogent, LNG-20 etc)
c) Vasectomy

Question 2.
Select the Assisted Reproductive Technique that uses an early embryo with upto 8 blastomeres.   (MAY-2010)
a) ZIFT
b) IUT
c) GIFT
d) IUI
Answer:
a) ZIFT

Question 3.
One among the contraceptive method is peculiar. Find the odd one. What is common among others?  (MARCH-2011)
a) Periodic abstinence
b) Coitus interruptus
c) Lactational amenorrhea
d) lUD’s
Answer:
d) lUD’s
Others are natural contraceptives/Natural methods/ Others have more chance of conception / IUD is the barrier method.

Question 4.
The treatment facility advertised on the brochure of a private clinic is shown below.  (MARCH-2011)
a) Can you suggest what type of a clinic it is ?
b) Make a brief note on any three of the treatment procedure.

Answer:
a) Infertility clinic / Fertility treatment clinic / Assisted Reproductive clinic or Hospital.
b) IVF-Invitro Fertilization
ZIFT – Zygote Intra Fallopian Transfer
GIFT – Gamete Intra Fallopian Transfer
IUI – Intra Uterine Insemination.

Question 5.
“STDs present a major health concern in both industralized and developing countries.”  (MARCH-2012)
a) What do you mean by STDs?
b) Name two STDs.
c) Suggest two preventive measures.
Answer:
a) Sexually transmitted diseases
b) Gonorrhoea and Syphilis
c) Avoid sex with unknown partners and use condom during coitus.

Question 6.
Find out the odd one from the following, write the reason.  (MAY-2012)
a) CuT
b) Cu7
c) LNG-20
d) Multiload – 375
Answer:
LNG-20

Question 7.
One couple came to know that they have a girl child during fourth month of pregnancy and they decide to do MTP.  (MAY-2012)
a) What is MTP ?
b) At which stage of pregnancy MTP relatively safe?
c) How will you respond to the decision of female foeticide by the couple?
Answer:
a) Medical termination of pregnancy
b) MTPs are safe during the first trimester, i.e., upto 12 weeks of pregnancy.
c) MTPs must be essential where continuation of the pregnancy could be harmful or even fatal either to the mother or to the foetus.

Question 8.
One of your friend argued that anti-retroviral drugs are effective medicine to treat AIDS.  (MAY-2012)
a) What is your opinion about it?
b) How HIV affect out immunity?
Answer:
a) It prevents the growth and multiplication of viruses
b) HIV enters into helper T-lymphocytes (TH), replicates and produce progeny viruses. The progeny viruses released in the blood attack other helper T-lymphocytes, as result the patient becomes immuno-deficient

Question 9.
Most often HIV infection occur due to conscious behaviour patterns. Do you agree with this statement? Substantiate your answer.  (MARCH-2013)
Answer:
No,
1) blood transfusion
2) During birth of child
Yes,
1) sexual contact
2) Intraveinous injection

Question 10.
Suggest the ART which may be successful in the following conditions. (MARCH-2013)
a) A female cannot produce ovum, but can provide suitable environment for fertilization and further development.
b) Male partner is unable to inseminate the female or has very low sperm count.
c) Fusion of gametes and zygote formation does not occur within the body of the female.
Answer:
a) Transfer of an ovum collected from a donor into the fallopian tube (GIFT – gamete intra fallopian transfer) of another female who cannot produce one, but provide suitable environment for fertilisation and further development
b) Intra cytoplasmic sperm injection (ICSI) Here a sperm is directly injected into the ovum. It is the procedure to form an embryo in the laboratory
c) In vitro fertilisation (IVF—fertilisation outside the body in almost similar conditions as that in the body) followed by embryo transfer (ET).

Question 11.
Prepare a pamphlet for Adolescent children to make them aware of alcohol and drug abuse. (MAY-2013)
Answer:
Education and counseling, moral education, Avoid undue peer pressure .visual publicity through TV, seeking professional and medical help etc.

Question 12.
One of your neighbour is suffering from itching, fluid discharge, slight pain and swelling in genital region. (MARCH-2014)
a) What do you think the disease he is suffering from?
b) What measures are to be taken to prevent such diseases?
Answer:
a) Sexually transmitted disease (STD) Eg-gonor- rhoea, syphilis etc.
b) 1) Avoid unknown sexual partner
2) Use condoms during coitus

Question 13.
Expand the following abbreviations which are commonly used in reproductive health: (MARCH-2014)
a) ART
b) ZIFT
Answer:
a) ART – Assisted reproductive techonology
b) ZIFT – Zygote intra fallopian transfer

Question 14.
______ and _____ are two surgical contraceptive methods in males and females respectively. (MAY-2014)
Answer:
Vasectomy,Tubectomy

Question 15.
Sex of the baby is determined by the father, not by the mother. Substantiate. (MAY-2014)
Answer:
ovum fertilises with a sperm carrying X- chromosome the zygote develops into a female (XX) and the fertilisation of ovum with Y-chromosome carrying sperm results into a male offspring. Hence the genetic make up of the sperm that determines the sex of the child.

Question 16.
Amniocentesis for sex determination is banned in our country? Is this ban necessary? Comment. One use of amniocentesis. (MAY-2014)
Answer:
Yes, Ban on amniocentesis for sex-determination to legally check increasing female foeticides. It is a foetal sex determination test based on the chromosomal pattern in the amniotic fluid surrounding the developing embryo.

Question 17.
Identify the diagram and write how it acts? (MARCH-2015)

Answer:
Copper T (CuT), lUDs increase phagocytosis of sperms within the uterus and the Cu ions released suppress sperm motility and the fertilising capacity of sperms.

Question 18.
Foetal sex can be determined by a test based on the chromosomal pattern from the amniotic fluid.  (MARCH-2015)
a) What is this test?
b) Revealing of sex determination through this test is banned. Is this ban necessary? Comment.
c) Invitro fertilization followed by embryo transfer is known as _____.
Answer:
a) Aminocentesis
b) Yes, Ban on amniocentesis for sex- determination to legally check increasing female foeticides.
c) Test tube baby programme

Question 19.
If proper care and attention is not given by adults, adolescents may become addicted to drugs/ alcohol.” What is your opinion about this statement? Substantiate your answer.  (MAY-2015)
Answer:
Adolescence is a bridge linking childhood and adulthood. It is the very vulnerable phase of mental and psychological development of an individual. Repeated use of drugs, the tolerance level of the receptors present in our body increases. Consequently the receptors respond only to higher doses of drugs or alcohol leading to greater intake and addiction.

Question 20.
Some techniques commonly used for infertility treatment are given below. Read them carefully and answer the questions.  (MAY-2015)
ZIFI , GJFF, ICSI, IUI, IVF
a) Which of the above technique is used forthe collection of sperm from the husband or a healthy donor and artificially introduced into the vagina or uterus of the female?
b) Distinguish between ZIFT and GIFT.
c) Write the common term used to denote ‘ tech-niques given above
Answer:
a) IUI
b) ZIFT- Ova from the wife/donor (female) and sperms from the husband/donor (male) are collected and are induced to form zygote under simulated conditions in the laboratory. The zygote or early embryos (with upto 8 blastomeres) are transferred into the fallopian tube
b) GIFT-Transferof an ovum collected from a donor into the fallopian tube of another female who cannot produce it ,but can provide suitable environment for fertilisation
c) Assisted reproductive technologies (ART)

Question 21.
Categorise the given birth control methods into three groups with proper heads.  (MARCH-2016)
Cervical caps, Vasectomy, Cu T, Tubectomy, Diaphragms, Condom, Lippes Loop
Answer:
lUDs- Cu T, LiPPes loop
Barrier method- Diaphrams, Condoms Cervical caps, surgical method – Vasectomy, Tubectomy,

Question 22.
Diagnostic report of two couples having infertility problems are given below:  (MAY-2016)
1) The woman cannot produce ovum.
2) The man has very low sperm count in semen. Suggest a suitable Assisted Reproductive Technologies (ART) for each problem in expanded form
Answer:
1) GIFT -Gamete intra fallopian transfer
2) lUI-Intra uterine insemination/AI-Artificial insemination.

Question 23.
Which of the following pairs of STDs is completely curable?  (MARCH-2017)
1) HIV, Hepatitis-B
2) Hepatitis-B, Gonorrhoea
3) Syphilis, Gonorrhoea
4) Chlamydomonas, genital-herpes
Answer:
3) syphilis, gonorrohea

Question 24.
a) What is ART?  (MARCH-2017)
b) Categorize the following ARTs based on their applications in male sterility and female sterility:
GIFT, Al
Answer:
a) In the case of infertility, the couples could be assisted to have children through certain special techniques commonly known as assisted reproductive technologies (ART),
b) GIFT-Female,
Al – Male

Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 1 Human Reproduction.

Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 1 Human Reproduction

Question 1.
Given below is the diagrammataic representation of human blastocyst. Observe the diagram and answer the following questions: (MARCH-2010)

a) Identify A and B
b) Write the functions of A and B.
Answer:
a) A – Inner cell mass, B – Trophoblast
b) A – Differentiate into embryo germ layers/gastrula B – Attachment to endometrium / form different embryonic membranes/ placenta formation/ nutritional supply.

Question 2.
When the urine sample of a lady is tested, presence of Human Chorionic Gonadotropin (HCG) is detected. (MARCH-2010)
a) What does the presence of HCG indicate?
b) Which is the source of HCG?
Answer:
a) Pregnancy
b) Placenta

Question 3.
The graph shown below shows the levels of LH and FSH at various stages of menstrual cycle. (MAY-2010)

a) Name the source of LH and FSH.
b) The level of LH is maximum during the middle day of the cycle. Mention its effect.
c) Note the function of LH in males.
Answer:
a) Pituitary gland
b) Helps for ovulation
c) Stimulates the synthesis of horrnones (androgens)

Question 4.

The above graph shows the level of ovarian hormones in a normally menstruacing woman during the follicular phase. (MARCH-2011)
a) Name ‘a’ and ‘b’
b) Mention the role of pituitary hormones in maintaining this condition.
c) Reconstruct the graph for Luteal phase.
Answer:
a) i) Estrogens
ii) Progesterone
b) FSH / Follicle stimulating Hormone, LH / Luteinizing Hormone
OR
Gonadotropins
One function each of FSH and LH.
c)

Question 5.
Some stages of the embryonic development are given below. Observe these diagrams and answer the questions. (MAY-2011)

a) What is A & B?
b) Name thetwo types of cells found in the blastocyst.
c) Which layer of blastocyst is attached to the endometrium? And name that process.
Answer:
a) A – Blastomere B – Morula
b) Trophoblast and inner cell mass
c) Trophoblast, Implantation

Question 6.
Observe the diagram provided (Do not copy the picture) (MARCH-2012)

a) Label A and B
b) On which day of menstrual cycle Graafian follicle rupture.
c) Name the process induces the rupture of Graafian follicle.
d) Write the name and function of the structure forming inside the ovary after the rupture of Graafian follicle.
Answer:
a) A – Primary follicle B – Tertiary follicle
b) 14th day
c) The rupture of Graafian follicle and the release of ovum is called ovulation.
d) The corpus luteum secretes large amounts of progesterone which helps in the maintenance of the endometrium.

Question 7.
The following statements compares the process of oogenesis and spermatogenesis. Which one is not true?  (MAY-2012)
a) Production of ovum ceases at certain age, but sperm production continues even in old men.
b) Oogenesis begins in the embryonic stages, but spermatogenesis starts at the onset of puberty.
c) Meiotic arrest occurs both in Oogenesis and spermatogenesis.
d) Polar bodies are formed in oogenesis.
Answer:
a) Replication
b) Transcription
c) Translation
d) Reverse transcription

Question 8.
The diagram represents a process of gametogenesis. Closely observe it and answer the following  (MARCH-2013)

Is it spermatogenesis or Oogenesis?
What does the smaller shaded circle represent? Write down two significance of production of the same.
Answer:
a) oogenesis
b) polar bodies
c) Retention of cytoplasm in ovum Maintaining one functional haploid ovum

Question 9.
Though one ovum is produced from a primary oocyte it can result into a male or female child after fertilization. But in the case of spermatocyte though 4 sperms are produced only two of them can result to a female child after fertilization”. Justify.  (MARCH-2013)
Answer:
Two types of sperms are produced one with x chromosomes and other withy chromosome. Sperm with x chromosome after fertilization results in the formation of female baby

Question 10.
Sterilization and IUDS are effective birth control measures, but lactational amenorrhea may not be so effective.  (MAY-2013)
a) How the sterilization procedure of males differ from that of females in preventing pregnancy?
b) Which part of the female reproductive organ is utilized for the IUD procedure? How this procedure prevents pregnancy?
c) Why the lactational amenorrhea is not so effective?
Answer:
a) In males the sterilization method is called vasectomy but in females it is called Tubectomy
b) uterus, lUDs suppresses sperm motility and fertilizing capacity of sperm or they make uterus unsuitable for implantation.
c) During intense lactation, menstrual cycle does not occur. Therefore the chance of conception is almost nil. But the method is effective only upto six months following delivery

Question 11.
Observe the diagram, and answer the questions: (MARCH-2013)
a) Identify A and B.
b) What is the function of C ?
c) In which of the marked part reduction division takes place? What is the significance of it?

Answer:
a) A – Spermatozoa, B-Primary spermatocyte
b) Sertoli cells provide nutrition to the germ cells.
c) Primary spermatocyte, chromosome number reduced to half

Question 12.
Diagram of a mammalian sperm’is given. Label the parts marked. (MAY-2014)

Answer:
A – Acrosome
B – Nucleus containing chromosomal material

Question 13.
Schematic representation of gametogenesis is given below. Identify A. Write one difference between A& B. (MARCH-2015)

Answer:
A) Spermatogenesis – It results 4 spermatozoa
B) Oogenesis – It results one ovum and polar body

Question 14.
1) In which part of the human reproductive system the following events occur? (MARCH-2015)
a) Fertilisation
b) Implantation
2) Diagram of a human biastocyst is given below. Identify A & B.

Answer:
a) ampullary-isthmicjunction
b) Endometrium of the uterus
A – inner cell mass
B – trophoblast

Question 15.
Choose the odd one from the following and write the common feature of others; (MAY-2015)
a) Estrogen
b) Androgen
c) Relaxin
d) Progesterone
Answer:
Androgen.
Others are ovarian hormones.

Question 16.
Complete the flow chart showing spermatogenesis by filling A and B and answer the questions: (MAY-2015)

a) What is the chromosome number of primary spermatocyte
b) What is the significance of reduction division in spermatocyte?
Answer:
A- Spermatogonia
B- Spermatids
a) Primary spermatocyte-Diploid number, in man it is 23 pair, spermatids-haploid number, in man it is 23
b) Reduction division helps to reduce chromosome number as half in gametes (haploid).
It helps keep chromosome number species as constant for many generations.

Question 17.
Match the columns A and B: (MARCH-2016)

Answer:

Question 18.
The process of fusion of a sperm with ovum is called _______. (MAY-2016)
Answer:
Fertilisation

Question 19.
Match columns A and B.  (MAY-2016)

Answer:

Question 20.
LH and FSH are gonadotrophins. Distinguish their roles in males and females.  (MARCH-2017)
Answer:
LH acts at the Leydig cells and stimulates synthesis and secretion of androgens.
Androgens stimulate the process of spermato-genesis.
FSH acts on the Sertoli cells and stimulates secretion of some factors which help in the process of spermiogenesis.
Female Rapid secretion of LH leading to rupture of Graafian follicle and release ovum (ovulation). FSHhelpsinthe growth and development of ovarian follicle.

Question 21.
Human female possess 44 + XX chromosome number. The chromosome number of secondary oocyte is  (MAY-2017)
a) 44 + X
b) 22 + X
c) 44 +XX
d) 22 +XX
Answer:
b) 22 + X

Question 22.
Observe the diagram and answer the questions:  (MAY-2017)

a) Identify A and B
b) Write the function of B.
Answer:
a) A – peri vitelline space
B- zona pellucida
b) Prevent the entry of further sperms after fertilization