Mutations

Question 1

Haemoglobin of sickle cell is ——

Answer 1

HbS ( occur beacuse glutamate is replaced by valine)

Question 2

Mutations in ——— is the most effected among the stages of central dogma

Answer 2

DNA

They say mutations are errors in DNA coding

Question 3

Causes of mutations

Answer 3

Inherited or spontaneous from environmental factors or errors in central dogma

Question 4

The effects of mutations are usually found at——— level

Answer 4

Protein

DNA——> mRNA——> proteins

Mutations anywhere will result in error in proteins synthesis

Question 5

What is a mutagens?

Answer 5

That can cause genetic mutations from physical or chemical substances and events

Question 6

Mutagens can be —— or ——

Answer 6

Endogenous- that is already inside the body

Exogenous- that comes from environmental surroundings

Question 7

The action of ROS can be prevented by ———

Answer 7

Antioxidants

When the ROS levels in ur body is too high, the doctors prescribe antioxidants to help prevent the ROS damage the DNA

Question 8

Etidium bromide can be ——— mutagen

Answer 8

Etidium bromine- intercalator

Exogenous mutagen

The fluorescent used in electrophoresis for vision under UV light.

But they can disrupt the form of double stranded DNA can cause mutations

Question 9

The action of base analogue

Answer 9

Pretend to be one base ( lets say Adenine)but function differently from what a normal base would function

Question 10

Carcinogens are also mutagens

Answer 10

True

Question 11

Are all mutations bad?

Answer 11

No. Natural evolution ——> mutations are crucial

Question 12

Nonsense mutation

Answer 12

The translation ends early then supposed to because of the point mutation experienced in the mRNA strand

Eg, GCT——>CGA
But instead there is a mutation and ACT——> UGA (Stop codon)

Question 13

Frameshift mutation

Answer 13

One nucleotide base added to the strand, and all the protein codings produce different amino acids

Question 14

New alleles can be produced by——

Answer 14

Mutations

Question 15

What is the chromosome number of zygote between the fusion of normal egg cell n and aneuploid Sperm n+1

Answer 15

2n+1

Question 16

In severe cases, the klinefeltor syndrome may be ——- or ———

Answer 16

XXY or XXXY

X inactivation can also apply to kinefeltor syndrome men just like in normal female

Question 17

Down syndrome karyotype, is it aneuploid or polyyploid?

Answer 17

Aneuploid, chromosome no= 47 not 3*23

Question 18

What is reciprocal and non-reciprocal translocation

Answer 18

Reciprocal; two chromosomes swapping segments.
Non-reciprocal- a chunk of chromosome moves to another

Question 19

Bacteria reproduces asexually. How does their variation to disease causing pathogens and resistant to antibiotics arise?

Answer 19

By three methods
1. Transformation- a bacteria takes up DNA from environment, such as plasmid. If the foreign DNA is pathogenic——> the recipient bacteria becomes pathogenic as well and pass it to their descendants

2. Transduction- by bacteriophage carrying a pathogenic DNA of a bacteria to another cell, some bacteriophages chop the DNA and make the transfer more likely

3 conjugation - one bacteria transfer DNA to another bacterium to which it is physically connected

Question 20

How do mutations in viruses arise?

Answer 20

1. Two types of viruses infect a host cell at the same time——> recombinant virus and gives rise to a new type of virus
2. Viral mutation - very high in RNA viruses —> RNA pol doesnt proofreads and many errors lead to mutation s