Question

35.

The chromosomes in eukaryotic cells are composed by structures called nucleosomes (?beads on a string?) which contribute to the chromosomal highly condensed nature. Find the incorrect statement.

	A.	Histone proteins in nucleosomes are octameric cores 2*(H2A + H2B + H3+ H4) and a single H1.
	B.	Eukaryotic chromosomes are composed of circular DNA molecules with proteins rich in acid amino acyl residues (e.g. aspartic acid and glutamic acid).
	C.	Histones can be chemically modified by phosphorylation, methylation and acetylation.
	D.	Analysis of primary structure of histone proteins reveals a high proportion of basic amino acyl residues (e.g. arginine and lysine).

36.

1. You have a segment of DNA that contains the following sequence:

   5'-GGACTAGACAATAGGGACCTAGAGATTCCGAAA-3'
   3'-CCTGATCTGTTATCCCTGGATCTCTAAGGCTTT-5'

   If you know that the RNA transcribed from this segment contains the following sequence:

   5'-GGACUAGACAAUAGGGACCUAGAGAUUCCGAAA-3'

   Which of the following choices best describes how transcription occurs?

   	A.	The bottom strand is the template strand; RNA polymerase moves along this strand from 3' to 5'.
   	B.	The bottom strand is the template strand; RNA polymerase moves along this strand from 5' to 3'.
   	C.	The top strand is the template strand; RNA polymerase moves along this strand from 5' to 3'.
   	D.	The top strand is the template strand; RNA polymerase moves along this strand from 3' to 5'.

38.

1. The codon for methionine is AUG. Which is the anticodon in tRNA^Met?

   	A.	5'-ATG-3'
   	B.	5'-AUG-3'
   	C.	5'-CAU-3'
   	D.	5'-CAT-3'

39.

1. Telomeres serve as caps at the ends of linear chromosomes. Which of the following is not true regarding the replication of telomeric sequences?

   	A.	The leading strand doubles back on itself to form a primer for the lagging strand.
   	B.	The lagging strand telomeres are not completely replicated by DNA polymerase.
   	C.	Telomeres are made of repeating sequences.
   	D.	Additional repeated sequences are added to the template strand.

41.

Which of the following statements is false?

	A.	In eukaryotes, all membrane-enclosed organelles are surrounded by one lipid bilayer.
	B.	Membrane lipids diffuse within the plane of the membrane.
	C.	Membrane lipids do not frequently flip-flop between one monolayer (?membrane leaf?) and the other.
	D.	Phospholipids will spontaneously form liposomes in polar solvents such as water.

42.

1. The following is correct regarding integral proteins:

   	A.	They are embedded in the membrane and if they extend through the lipid bilayer they are called transmembrane proteins.
   	B.	They are also called intrinsic.
   	C.	They can be extracted from the membrane if the cells are treated with detergents.
   	D.	All of these

Answer 1

Question 35) option B is wrong statement

.	Eukaryotic chromosomes are composed of circular DNA molecules with proteins rich in acid amino acyl residues (e.g. aspartic acid and glutamic acid). Eukaryotes chromosome are not circular, instead made up of linear chromosomes .

Question 36) option A is correct

The bottom strand is template strand; The RNA Polymeras along the strand from the 3' to 5' direction

Template strans is always in 3' to 5' direction. RNA polymerase move from 3 to 5' direction lead to synthesis of mRNA from 5' to 3' direction.

Question 38) option C

5' CAU-3'

5' AUG 3' CODON

3' UAC 5' ANTICODON on tRNA

Question 39). OPTION A is not correct

A, The leading strand doubles back on itself to form a primer for the lagging strand.

On lagging strand priners required in multiple numbers and synthesized by DNA prinase , leading stand dies not have to take anything here .

Question 41) option A is false statement

In eukaryotes, all membrane-enclosed organelles are surrounded by one lipid bilayer.

All membrane bound organelle are not enclosed by one lipid bilayer example mitochondria are enclosed by double layer, nucleus also

Question 42) option d is  correct  

All option are correct