3.8 Mutations and stem cells

Question 1

What is a mutation ?

Answer 1

A change in the DNA base sequence of a gene

Question 2

What can a gene mutation result in ?

Answer 2

A different amino acid sequence in the primary structure that causes hydrogen and ionic bonds to form in different locations, which results in a different 3D shape

Question 3

What is an addition mutation ?

Answer 3

One extra base is added to the sequence

Question 4

What is the result of an addition mutation ?

Answer 4

Frameshift- alters the codons which can code for different amino acids

Question 5

What is a deletion mutation ?

Answer 5

One base is deleted from the sequence

Question 6

What is the result of a deletion mutation ?

Answer 6

Causes frameshift to the left

Question 7

What is a substitution mutation ?

Answer 7

One of the bases is changed for a different base

Question 8

What is an inversion mutation ?

Answer 8

When a section of bases detach from the DNA sequence, but when they rejoin they are inverted so this section of code is back to front

Question 9

What is duplication ?

Answer 9

One particular base is duplicated at least once in the sequence

Question 10

What effect does a duplication mutation have ?

Answer 10

Cases frameshift to the right and a different sequence of amino acids are coded for

Question 11

What is translocation ?

Answer 11

A section of bases on one chromosome detaches and attaches onto a different chromosome

Question 12

What are the impacts of translocation ?

Answer 12

Can cause significant impact to gene expression and therefore the resulting phenotype

Question 13

What are stem cells ?

Answer 13

They are undifferentiated cells that can continually divide and become specialised

Question 14

What is the name of the process by which stem cells become specialised ?

Answer 14

Differentiation

Question 15

What is a totipotent stem cell ?

Answer 15

Can differentiate into any type of body cell

Question 16

Where are totipotent cells found ?

Answer 16

In early mammalian embryos

Question 17

What are pluripotent stem cells ?

Answer 17

Can differentiate into almost any cell

Question 18

Where are pluripotent stem cells found ?

Answer 18

Found in embryos

Question 19

What are pluripotent stem cells used for ?

Answer 19

Treating human disorders

Question 20

What is a multipoint cell ?

Answer 20

Can develop into most cell types

Question 21

What is a unipotent cell ?

Answer 21

Can only differentiate into one type of cell

Question 22

Where are multipoint and unipotent cells found ?

Answer 22

Found in mature mammals

Question 23

How are induced pluripotent stem cells produced ?

Answer 23

From adult somatic cells using protein transciption factors

Question 24

Why are IPS used ?

Answer 24

To overcome some of the ethical issues associated with using embryonic stem cells