Question 3 :
Choose the correct answers from the alternatives given.<br>Place the following in the correct order concerning the passage of sperm from the testes to the outside of the body<br>1. ductus (vas) deferens, 2. rete testes, 3. seminiferous tubules, 4. Epididymis, 5. Urethra,6. straight tubules<br>

Question 5 :
Leydig&#160;cells in adult mammals produce which one of the following hormones?

Question 6 :
In the rhythm method of birth control, the couple abstain from intercourse

Question 7 :
Assertion: Copper-T is an effective contraceptive device in human females. Reason: Copper-T prevents passage of sperms from vagina upwards into fallopian tubes.

Question 9 :
Which of the following is regarded as an absolute contraindication of oral contraceptive pill?

Question 11 :
Read the assertion (A) and reason (R) carefully to mark the correct option out of the options given below:<b><br>A</b>. There are some plants which have in their life-cycles neither the process of fertilization nor they have meiosis.<br><b>R</b>. In these plants, the vegetative or somatic plant body helps in the propagation of the plant.

Question 13 :
When you study a slide showing different stages of budding in yeast, youobserve the following stages :<br>I. The bud may get separated from the parent body and develop intoa new individual.<br>II. The body of the bud develops and gives rise to another baby bud.<br>III. A bud comes out in any direction from the body of the parent cell.<br>IV. Thus they may form a colony.<br>The proper sequence of the above stages is

Question 17 :
Select the correct statements for the process of budding in yeast:<br/>I. A bud arises from a particular region on a parent body.<br/>II. A parent cell divides into two daughter cells, here the parental identity is lost.<br/>III. Before detaching from the parent body a bud may form another bud.<br/>IV. A bud when detaches from the parent body grows into a new individual.

Question 18 :
Which of the following mostly shows the sexual dimorphism?<span id="_wysihtml5-undo" class="_wysihtml5-temp">

Question 20 :
What observation can be made by viewing the slides under the microscope on binary fission in Amoeba and budding in yeast?

Question 21 :
Assertion: Histones are basic proteins of major importance in packaging of eukaryotic DNA. DNA and histones comprise chromatin forming the bulk of eukaryotic chromosome. Reason: Histones are of five major types: H1, H2A, H2B, H3 and H4.

Question 22 :
&#34;It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for genetic material&#34; - This is written by<br/>

Question 23 :
Out of A-T, G-C pairing, bases of DNA may exist in alternate valency state owing to arrangement called as

Question 26 :
In&#160;the Watson and Crick model of DNA, the steps of the ladder are composed of

Question 27 :
No. of of phosphoester bonds found in one turn of DNA is ____________.

Question 28 :
Read the following statements and select the Correct option.<br>(i) Loosely packed and lightly stained region of chromatin are called as heterochrormatin.<br>(ii) Densely packed and dark stained region of chromatin are called as euchromatin.<br>(iii) A typical nucleosome contains 200 bp of DNA helix.<br>

Question 30 :
If the total amount of adenine and thymine in a double-stranded DNA is 45%, the amount of guanine in this DNA will be<br/>

Question 31 :
Choose the correct answer from the alternatives given :<br>Referto the given steps Of DNA replication.<br>(i)Exposure of DNA strands<br>(ii)Synthesis of RNA primer<br>(iii)Activation of deoxyribonucleotides<br>(iv)Chain formation<br>(v)Base pairing<br>(vi) Proof reading and DNA repair<br>(vii)DNA polymerase attaches at Or site<br>Selectthe correct sequence of DNA replication.<br>

Question 32 :
A $340\overset {\circ}{A}$ long segment of DNA molecule has $20$ thymine nitrogenous bases, what will be the number of guanine nitrogen bases in the same segment?

Question 33 :
Taylor conducted the experiments to semiconservative mode of chromosome replication on

Question 35 :
Nobel Prize to A. Kornberg and S. Ochoa was given for

Question 39 :
Palaeontologists unearthed a human skull during excavation.&#160; A small fragment of the scalp tissue was still attached to it. Only little DNA could be extracted from it. If the genes of the ancient man need to be analysed, the best way of getting sufficient amount of DNA from this extract is <br/>

Question 43 :
Why does synthesis of DNA proceed only in the $5'$ to $3'$ direction?

Question 44 :
Choose the correct answer from the alternatives given :<br>Watson and Crick (1953) proposed DNA double helix model and won the Nobel Prize; their model of DNA was based on<br><b></b>(i) X-ray diffraction studies of DNA done by Wilkins and Franklin<br>(ii) Chargaffs base equivalence rule<br>(iii) Griffiths transformation experiment<br>(iv) Meselson and Stahls experiment.<br>

Question 45 :
If percentage of cytosine is 18%, what will be the percentage of adenine?<br/>

Question 46 :
DNA in the nucleus of rabbit egg is 1.8 picograms, its liver cell will have mass of DNA ______ picograms.

Question 48 :
Choose the correct answers from the alternatives given.<br>What is the function of DNA ligase in recombinant technology?

Question 49 :
Choose the correct answer from the alternatives given :<br>Whichof the following phenomena was experimentally proved by Meselson and Stahl?