CBSE Class 12 Biology Human Reproductive Health Question Bank

 

Question: Name the technique to know the genetic disorders in the foetus .
Answer : Amniocentesis

Question: What is MTP?
Answer : Medical termination of pregnancy

Question: List one drawback of surgical methods of birth control.
Answer : Poor reversibility

Question: Which period of pregnancy is safer for MTP?
Answer : First trimester

Question: What are the measures one has to take to prevent from contracting STDs?
Answer :  Avoid multiple partners , early detection

Question: Explain the technique amniocentesis .How is this technique misused?
Answer : Foetal sex determination based on chromosomal pattern in the  amniotic fluid surrounding the developing embryo , female foeticide

Question: Describe the three different practices under natural methods of birth control.
Answer : Periodic abstinence , withdrawal , lactational amenorrhea

Question: What are barrier methods of birth control? Explain.
Answer : Prevent physical meeting of sperm and egg condoms in males , diaphragms, cervical caps vaults in females , spermicidal creams , jellies foams

Question: Expand IUDs. Explain the various methods of IUDs.
Answer : Intra uterine devies , non- medicated , Cu releasing , hormone releasing 

Question: What is sterilization? Explain the various methods.
Answer : Surgical method , vasectomy in males- vas deferens cut / tied , tubectomy in females fallopian tube cut/ tied

Question: How do oral contraceptives function? What is the advantage of Saheli?
Answer : Progestogen or progestogen – estrogen combination 21 days ,inhibit 1+1+1 ovulation implantation , alter the quality of cervical mucus to prevent/ retard the entry of sperms saheli – non steroidal once a week pill

Question: What is an ideal contraceptive for women and explain its contraceptive role?
Answer : IUDs . increase phagocytosis , suppress sperm motility fertilizing capacity 1 x 3 of sperm uterus unsuitable for implantation cervix hostile to sperms

Question: How do the natural, barriers, IUD's, Oral pills and Surgical methods help in Contraception?
Explain.
Answer : Natural -avoiding chances of ovum sperm meeting ,barrier –prevent 1 x 5 ovum sperm meeting , IUD – phagocytosisi,pills – inhibit ovulation , surgical prevent gamete transfer

Question: What is STD? List out the various STD's .How is it transmitted? What are its symptoms? What are the complications the STD could lead to?
Answer : Sexually transmitted diseases VD RTI Gonorrhoea syphilis genital herpes etc , sharing injection needles trans fusion of blood etc itching fulid discharge slight pain swellings ,PID abortions still births ectopic pregnancy infertility

Question: Explain the various methods of Assisted Reproductive Technologies.
Answer : IVF , ET, Test tube baby programme , ZIFT/, IUT/ ,GIFT/, ICSI/,IUI 

Question: Expand RCH,CDRI,MMR,IMR,AIDS,VD,RTI,IUT,IUI,AI,IVF,STD,MTP,IUD,ZIFT,GIFT,ART,ICSI ,PID.
Answer : Reproductive and child health care programme ,Central drug research institute ,Matrenal mortality rate , infant mortality rate ,Acquired immune deficiency syndrome , veneral disease,Reproductive tract infection ,Intra uterine transfer , intra uterine insemination ,Artificial insemination , in vitro fertilization , Sexually transmitted diseases , medical termination of pregnancy,Intra uterine devices ,Zygote intra fallopian transfer, gamete intra fallopian transfer, assisted reproductive technology , Intra cytoplasmic sperm injection Pelvic inflammatory diseases

Question: Mrs. X was blamed for being childless though the problem was due to low sperm counts in the ejaculates of her husband. Suggest a technique which could help the couple to have a child.
Answer : IVF and its detail process and importance.

Question: Why is ZIFT a boon to childless couples?
Explain the procedure. 
Answer : ZIFT (Zygote Intra Fallopian Transfer) is a boon to childless couples as it helps them to become parents. In this technique, ova from wife/donor female and sperms from husband/donor male are induced to form zygote in laboratory. Zygote is allowed to divide upto 8 blastomeres stage and it is at this stage, a zygote or early embryo is transferred into the Fallopian tube. Implantation takes place in the uterus where further development takes place.

Question: State any four methods to overcome infertility in human couples. 
Answer : Following are the four methods to overcome infertility problems in human couples :
(i) Test tube baby programme : In this method, the fusion of ovum and sperm is done outside the body of a woman (in vitro fertilisation), to form zygote which is allowed to divide to form embryo. The embryo is then implanted in the uterus where it develops into a foetus and then into the child.
(ii) Intra Cytoplasmic Sperm Injection (ICSI) : In this technique, embryo is formed in the laboratory by directly injecting the sperm into the ovum followed by embryo transfer.
(iii) Artificial Insemination Technique (AIT) : Semen (containing sperms) from husband or donor is artificially introduced into vagina or uterus (IUI). (iv) Gamete Intra Fallopian Transfer (GIFT) : Sperm and unfertilised ova are transferred into the Fallopian tube of the female to complete fertilisation and further development.

Question: A large number of married couples over the world are childless. It is shocking to know that in India the female partner is often blamed for the couple being childless.
(a) Why in your opinion the female partner is often blamed for such situations in India? Mention any two values that you as a biology student can promote to check this social evil. (b) State any two reasons responsible for the cause of infertility.
(c) Suggest a technique that can help the couple to have a child where the problem is with male partner. 
Answer : (a) There is a common myth prevailing in our society that inability of a couple to have child is due to the infertility of female partner only, it is because female carries the child in her womb. Being a biology student we should create awareness among people that both male and female partners equally contribute for having a child. This is because baby is formed from zygote that is formed by fusion of both male and female gametes. Hence, infertility in either male or female can be responsible for inability to have child. Infertility in both males and females can be easily cured as there are so many specialised infertility clinics which provide treatments to childless couples. In case treatment is not possible, the couples can be assisted to have children through certain special techniques called the assisted reproductive technologies.
(b) Infertility can be due to following reasons:
(i) Infertility in males can be due to low sperm count, blockage of vasa deferentia and vasa efferentia affecting sperm transport, hormonal deficiency, impotency (inability to erect and penetrate penis into vagina of female) and presence of anti-sperm antibodies in semen.
(ii) Infertility in females can be due to ovulation disorders, abnormality in uterus, blockage or damage to Fallopian tubes, chronic endometritis, fibroid in uterus, etc.
(c) If the problem is with a male partner then artificial insemination technique can be adopted. In this technique the sperms collected either from the husband or a healthy donor are artificially introduced either into the vagina or into the uterus (IUI-Intra- Uterine Insemination) of the female.

Question: Your school has been selected by the Department of Education to organise and host an interschool seminar on “Reproductive Health-Problems and Practices”. However, many parents are reluctant to permit their wards to attend it. Their argument is that the topic is “too embarrassing”. Put forth four arguments with appropriate reasons and explanation to justify the topic to be very essential and timely.
Answer : Parents should encourage their children to attend such seminar as they will get right information regarding myths and misconceptions about sex-related aspects. Following are the four points to justify this topic to be essential:
(i) Awareness of problems due to uncontrolled population growth, social evils like sex abuse and sex-related crimes, etc. need to be created so that children should think and take up necessary steps to prevent them and thereby build up a reproductively healthy society.
(ii) Large group of school students comprises of adolescents who have attained puberty, therefore, these seminars are necessar y to provide medical help and care for reproduction related problems like menstrual problems, infertility, pregnanc y, deliver y, contraception, abortions, etc.
(iii) Knowledge about sexually-transmitted diseases (STDs) is essential as children should be aware that unprotected sex with multiple partners results in the transmission of sex-related problems.
(iv) Increasing population is a major problem of India which is directly related with reproductive health. Children should be aware of family planning programmes such as reproductive and child health care (RCH) programmes.

Question: The length of DNA usually depends on
a) position of nucleotides
b) number of nucleotides
c) Both (a) and (b)
d) None of the above

Answer: b

Question: When a phosphate group is linked to ...A... group of nucleoside through ...B... bond, a corresponding ...C... is formed.
Choose the correct option for A, B and C.
a) A–5¢ OH, B–phosphodiester bond, C–nucleotide
b) A–3¢ OH, B–phosphodiester bond, C–nucleotide
c) A–2¢ OH, B–phosphodiester bond, C–nucleotide
d) A–5¢ OH, B–phosphodiester bond, C–nucleoside

Answer: a

Question: Nitrogenous bases are linked to sugar by
a) hydrogen bond
b) phosphodiester bond
c) N-glycosidic bond
d) O-glycosidic bond

Answer: c

Question: A polymer or a polynucleotide chain has at one end a free ........A....... at 5' end of sugar, similarly at the other end of
the polymer the sugar has a free .....B..... of 3' group.
a) A – Phosphate moiety, B – OH
b) A – OH, B – Phosphate moiety
c) A – COOH, B – Phosphate moiety
d) A – Phosphate moiety, B–COOH

Answer: a

Question: Isotopes used by Hershey and Chase were
a) ³²P and ³⁵S
b) ³⁵P and ³²S
c) ³⁴P and ³¹S
d) ³⁰P and ³²S

Answer: a

Question: Find the incorrect match.
a) A bacteriophage (∅×174) –5386 nucleotides
b) Bacteriophage lamda – 48502 base pairs
c) E. coli – 46×10⁶×bp
d) Haploid content of human DNA – 3.3×10⁶bp

Answer: d

Question: In prokaryotes (such as E. coli) ...A... nucleus is not present, the DNA is not scattered throughout the cell. DNA is ...B... charged and holded by the ...C... charged proteins. This structure in prokaryotes is called ...D... . Choose the correct option for A, B, C and D.
a) A–undefined, B–negatively, C–positively, D–nucleoid
b) A–undefined, B–negatively, C–positively, D–nucleus
c) A–defined, B–negatively, C–positively, D–nucleoid
d) A–defined, B–positively, C–negatively, D–nucleoid

Answer: c

Question: Choose the incorrect option.
a) Friedrich Miescher in 1869 identified DNA as an acidic substance and named it nuclein
b) Erwin Chargaff said, the ratio between A and T and G and C of dsDNA are constant and equals one
c) The two strands of dsDNA are complementary to each other
d) None of the above

Answer: d

Question: What was unique in Griffith’s experiments?
a) DNA was found to be the genetic material
b) RNA was found to be the genetic material
c) Something from dead organisms could change the living cells
d) Viruses can live in bacteria

Answer: c

Question: Which of the following is not the correct salient feature of double-helix structure of DNA?
a) Two polynucleotide chains have backbone of sugar and phosphate and bases project inside
b) Two chains have antiparallel polarity, i.e. one is 5' → 3' and other is 3'→5'
c) Adenine forms three hydrogen bonds with thymine and guanine forms two hydrogen bonds with cytosine
d) The plane of one base pair stacks over the other in double helix in addition to H-bond to confer extra statbility to helical structure

Answer: c

Question: Hershey and Chase concluded that viral infecting agent in their experiment was
a) Protein
b) DNA
c) RNA
d) Both (b) and (c)

Answer: b

Question: Why both the strands of DNA are not copied during transcription?
a) Because RNA molecule with different sequences will be formed
b) Because RNA molecule with same sequences will be formed
c) Because RNA molecule with identical sequences will be formed
d) Because DNA molecule with different sequences will be formed

Answer: a

Question: RNA is the genetic material in
a) All bacteria
b) Tobacco Mosaic Viruses (TMV)
c) QB bacteriophage
d) Both (b) and (c)

Answer: d

Question: Lightly stained part of chromatin which remains loosely packed and is transcriptionally active named as
a) euchromatin
b) heterochromatin
c) chromatosome
d) chromonemata

Answer: a

Question: Who experimentally proved the semiconservative mode of DNA replication?
a) Mathew Meselson
b) Franklin Stahl
c) Both (a) and (b)
d) Watson and Crick 

Answer: c

Question: Similar experiments like Meselson and Stahl was performed by Taylor in 1958. The experimental organism of Taylor
was
a) Vicia faba
b) Fungi
c) E. coli
d) Protista

Answer: a

Question: DNA-dependent DNA polymerases catalyses polymerisation in which direction?
a) 3' → 5'
b) 5' → 2'
c) 5' → 3'
d) 2' → 5'

Answer: c

Question: In Meselson and Stahl’s experiment (1958), DNA extracted from the culture one generation after the transfer from 15N to 14N medium had a hybrid (or intermediate) density. Why?
a) Because the generation time of E. coli (culture) was about 20 minutes
b) Because it would take 20 minutes for RNA replication
c) Because it would take 20 minutes for replication of DNA to RNA (transcription)
d) Because it would take 20 minutes for translation RNA to protein

Answer: a

Question: Deoxyribonucleoside triphosphate serve dual purposes. The purposes are
a) act as substrate and decrease reaction rate
b) provide energy for polymerisation and act as substrate
c) decrease reaction rate and provide energy for polymerisation
d) Synthesise RNA primer and decrease reaction rate

Answer: b

Question: In bacteria, which enzyme catalyses the transcription of all types of RNA (mRNA, tRNA and rRNA)?
a) DNA-dependent RNA polymerase
b) DNA-dependent DNA polymerase
c) RNA-dependent RNA polymerase
d) RNA-dependent DNA polymerase

Answer: a

Question: Choose the correct option.
a) Pyrimidines include adenine and guanine
b) Pyrimidines include cytosine, uracil and thymine
c) Purines include adenine and thymine
d) Purines include guanine and cytosine

Answer: b

Question: For long DNA molecules, the two strands of DNA cannot be separated in its entire length due to the requirement of
a) enzymes
b) high energy
c) RNA
d) phosphate and nucleotide

Answer: b

Question: Name the nucleotide added to 5¢ end of hnRNA in capping.
a) Ethyl cytosine triphosphate
b) Ethyl guanosine triphosphate
c) Methyl guanosine triphosphate
d) Methyl cytosine triphosphate

Answer: c

Question: Codons are non-ambiguous, which means that one codon codes for
a) more than one amino acid
b) two amino acids
c) Only one amino acid
d) non-sense amino acid

Answer: c

Question: Why glucose and galactose cannot act as an inducer for lacoperon?
a) Because they cannot bind with the repressor
b) Because they can bind with the repressor
c) Because they can bind with the operator
d) Because they can bind with the regulator

Answer: a

Question: Degeneracy refers to
a) one amino acid has more than one code triplet
b) one amino acid has only one code triplet
c) codons which specify the same amino acids differ only in the third base of the triplet
d) Both (a) and (c)

Answer: d

Question: The process of polymerisation of amino acids to form a polypeptide is
a) transcription
b) replication
c) translation
d) polymerisation

Answer: c

Question: Choose the correct option.
a) Splicing represent the dominance of RNA world
b) The presence of introns is reminiscent of antiquity
c) Split gene arrangements represent an ancient feature of the genome
d) All of the above

Answer: d

Question: UTRs present on mRNA refer to
a) Untranscribed regions at both 5' end and 3' end
b) Untranslated regions at 5' end
c) Untranslated regions at both 5' end and 3' end
d) Untranslated regions at 3' end

Answer: c

Question: Choose the incorrect option for tRNA molecule.
a) It has an anticodon loop that has bases complementary to the code
b) It has an amino acid acceptor end to which it binds to amino acids
c) tRNA are not specific for each amino acid
d) tRNA looks like a clover leaf

Answer: c

Question: Termination of protein synthesis or translation requires
a) Both stop signal and starting codon
b) Both starting codon and release factor
c) Both release factor and stop codon
d) GUG and AUG codon

Answer: c

Question: In prokaryotes, control of the rate of ...A... is the pre-dominant site for the control of gene expression. In a transcription unit, the activity of ...B... at a given promoter is in turn regulated by interaction with ...C... proteins, which
affects its ability to recognise the start sites. Complete the statement filling the correct options in given blanks.
a) A–RNA replication, B–DNA polymerase, C–accessory
b) A–transcriptional initiation, B–RNA polymerase, C–accessory
c) A–translational initiation, B–RNA polymerase, C–accessory
d) A–DNA replication, B–RNA polymerase, C–accessory

Answer: b

Question: Which among the following process occur(s) during charging or aminoacylation of tRNA?
a) Activation of amino acids in the presence of ATP
b) Linking of amino acids to their cognate tRNA
c) Both (a) and (b)
d) None of the above

Answer: c

Question: Positively regulatory proteins are called
a) activator
b) repressors
c) necessary proteins
d) accessory proteins

Answer: a

Question: Lactose is a substrate for
a) galactosidase
b) a-galactosidase
c) b-galactosidase
d) g-galactosidase

Answer: c

Question: Lactose is transported into cells through
a) b-galactosidase
b) permease
c) transacetylase
d) transferase

Answer: b

Question: Which of the following option is true for Human Genome Project (HGP)?
a) It was launched in the year 1990 and was called mega project
b) Total estimated cost of the project would be 9 billion US dollars
c) It aims to identify all 20000-25000 genes in human DNA
d) All of the above

Answer: d

Question: Lactose is a substrate for
a) galactosidase
b) a-galactosidase
c) b-galactosidase
d) g-galactosidase

Answer: c

Question: Identify the incorrect pair.
a) Expressed sequence tags — Genes that are express as RNA
b) Sequence annotation — Sequencing genome with coding sequences
c) Automated DNA sequences — Work on the principle developed by Frederick Sanger
d) None of the above

Answer: b

Question: DNA fingerprinting involves identifying the differences in some specific regions in DNA sequence called
a) non-repetitive DNA
b) coding DNA
c) non-coding DNA
d) repetitive DNA

Answer: d

Question: Alec Jeffreys used a satellite DNA as probe that shows very high degree of polymorphism. It was called as
a) Short Number of Tandem Repeats (SNTRs)
b) Large Number of Tandem Repeats (LNTRs)
c) Variable Number of Tandem Repeats (VNTRs)
d) All of the above

Answer: c

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