Molecular Basis Of Inheritence

Question 1

What does genetic code determines?

Answer 1

Sequence of amino acids in proteins

Question 2

The length of DNA is usually defined as?

Answer 2

Number of nucleotides (or a pair of nucleotides) present in it.

Question 3

Place in asceding order of no of nucleotides or base pairs. Bacteriophage phi*174 ,bacteriphage lamba,e coli, haploid content of human.

Answer 3

Bacteriphage phi174(5386) < bacteriphage lambda(48502) < e coli(4.610^6) < human haploid(3.3*10^9)

Question 4

Linkage between sugar and base

Answer 4

N -glycosidic linkage

Question 5

Linkage between two nucleotides

Answer 5

Phosphodiester linkage

Question 6

What does 5’ end of chain has

Answer 6

Phosphate moiety

Question 7

What does 3’ end of chain has

Answer 7

OH group at 3’ carbon of sugar

Question 8

Pyrimidines are how many ring compund?give example

Answer 8

Single ring

Thymine,cytosine,uracil

Question 9

In purines how many rings are seen?give example

Answer 9

Two

Adenine guanine

Question 10

Thymine is also called

Answer 10

5 methyl uracil

Question 11

Make structure if adenine and uracil

Answer 11

.

Question 12

Diff between deoxyribose and ribose

Answer 12

In ribose there is OH group at 2’ carbon

Question 13

What is pitch in DNA.

Answer 13

Distance (line) parallel to the helix that corresponds to one turn.
34 angstrom
3.4nm

Question 14

How many base pairs are there in one pitch/one turn

Answer 14

10

Question 15

Lenth of one base pair

Answer 15

0.34nm

Question 16

What is B Dna

Answer 16

Dna with structural characteristics of 3.4nm pitch

Question 17

The two chains are coiled in which fashion?

Answer 17

Right handed

Question 18

What was the hallmark proposition of double helical model of DNA? Watson and Crick stole that idea from whom?

Answer 18

Base pairing between the two strands of nucleotide chains.
This was based on the proposition made by Erwin Chargaff that the ration of adenine and thymine and guanine and cytosine is one.

Question 19

Who was the first to detect DNA as the acidic substance present in nucleus?when?

Answer 19

Friedrich Meischer in 1869

Question 20

When and who proposed double helix model of DNA structure?

Answer 20

James Watson and Francis Crick

In 1953

Question 21

Double helical modelwas based on x ray diffraction data produced by?

Answer 21

Maurice Wilkins and Rosalind Franklin

Question 22

Who proposed central dogma?

Answer 22

Francis Crick

Question 23

What is the typical dimension of nucleus?

Answer 23

10^-6

Question 24

What is the length of Dna in human

Answer 24

2.2m

Question 25

Is DNA scattered in whole cell of prokaryotes as they don’t have nucleus?if not how it is organised?

Answer 25

Itdna is negatively charged and held together by positively charged proteins in region termed as nucleoid.this dna is organised in large loops held by proteins.

Question 26

Why histones can bind Dna?

Answer 26

Because they are positively charged and basic as dna is negatively charged and acidic.
So they attract each other

Question 27

Histones are rich in which type of amino acids?what type of chrage their residues carry?

Answer 27

Lysine and arginine.

Positive

Question 28

Dna plus histone octamer?how does ot look lik

Answer 28

Nucleosome.beads on string

Question 29

How many base pair of dna is wrapped around in one nucleosome?

Answer 29

200

Question 30

How many beads can be seen in one cell?

Answer 30

3.3*10^7

Question 31

The beads on string structure is packaged to form?

Answer 31

Chromatin fibres

Question 32

Chromatin fibres are further coiled to form?

Answer 32

Chromosome

Question 33

Where are non histone proteins used?

Answer 33

For packaging of chromatic fibres at higher level.

Question 34

What is euchromatin?

Answer 34

The region of chromatin in typical nucleus that is loosely packed and lightly stained.

Question 35

What is hetrochromatin?

Answer 35

Region of chromatin that densely packed and stains dark.

It is inactive .