The nuclear structure observed by Henkings in 50% of the insect sperm after spermatogenesis was
- X body
- Autosome
- Y chromosome
- Nucleolus
The Correct Option is A
Solution and Explanation
Further investigations by other scientists ledtotheconclusion that the ?X body? of Henking was in fact a chromosome and that is why it was given the name X-chromosome. It was also observed that in a large number of insects the mechanism of sex determination is of the XO type, i.e., all
eggs bear an additional X-chromosome besides the other chromosomes (autosomes). On the other hand, some of the sperms bear the X-chromosome whereas some do not. Eggs fertilised by sperm having an X-chromosome become females and, those fertilised by sperms that do not have an X-chromosome become males.
Top Questions on The DNA
- Which of the following statement(s) about eukaryotic DNA topoisomerase is/are correct?
- What is the fate of a piece of DNA carrying only gene of interest which is transfered in to an alien organism?
A. The piece of DNA would be able to multiply itself independently in the progeny cells of the organism.
B. It may get integrated into the genome of the recipient.
C. It may multiple and be inherited along with the host DNA.
D. The alien piece of DNA is not an integral part of chromasame.
E. It shows ability to replicate.
Choose the correct answer from the options given below: - The DNA present in chloroplast is:
- Hind II always cuts DNA molecules at a particular point called recognition sequence and it consists of:
- Arrange the following steps of ‘Polymerase chain Reaction’ in a correct sequence.
(A) Annealing of primers
(B) Amplified DNA
(C) Denaturation of DNA
(D) Extension of primers
Choose the correct answer from the option given below
Questions Asked in KEAM exam
- Suppose there are 5 alike dogs, 6 alike monkeys and 7 alike horses. The number of ways of selecting one or more animals from these is
- KEAM - 2023
- permutations and combinations
Let S={\(a,b,c\)} be the sample space with the associated probabilities satisfying \(P(a)=2P(b)\) and \(P(b)=2P(c).\)Then the value of \(P(a)\) is
- KEAM - 2023
- Probability
- If, \(x∈(0,π)\) satisfies the equation \(6^{1+sinx+sin^2x....}=36\) ,then the value of \(x\) is_____.
- KEAM - 2023
- Trigonometric Functions
Which are the non-benzenoid aromatic compounds in the following?
- KEAM - 2023
- Hydrocarbons
Car P is heading east with a speed V and car Q is heading north with a speed \(\sqrt{3}\). What is the velocity of car Q with respect to car P?
- KEAM - 2023
- Motion in a plane
Concepts Used:
Discovery of DNA
DNA - Discovery
Many individuals believe that American biologist - "James Watson" and English physicist - “Francis Crick” discovered DNA in the 1950s. Actually, this is not the case. Preferably, DNA was first recognized in the late 1860s by Swiss chemist - “Friedrich Miescher”.
Read More: Structure of DNA
What actually DNA is?
DNA is self-replicating material that exists in every living organism. In easiest terms, it is a carrier of all genetic information. It contains the instructions required for organisms to develop, grow, survive, and reproduce. It’s one of the longest molecules that contain our genetic “code,” or recipe. This recipe is the initial point for our development, but DNA’s interaction with outside impacts such as our lifestyle, environment, and nutrition ultimately forms human beings.
DNA is a composition of molecules known as nucleotides. Each nucleotide comprises a sugar and phosphate group, also nitrogen bases. These nitrogen bases are further tumbledown into four types, including:
- Adenine (A)
- Cytosine (C)
- Guanine (G)
- Thymine (T)
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