The gene pool

Question 1

Gene pool

Answer 1

A gene pool is the sum of alleles possessed by an entire population at one given time.

Question 2

What causes/results in increased genetic diversity

Answer 2

The larger and more diverse gene pool will contain a greater variety of gene and alleles which results in increased genetic diveristy

Question 3

Mutation

Answer 3

A Permanente change inthe DNA sequence

Question 4

How can mutations be advantgeous

Answer 4

muatations can be advanteous by providing a selective advantage over other phenotypes

types of advatenouse mtuations are HIV resistnace and lactose tolereance

Question 5

a mutation that is deleterious

Answer 5

a mutation that can cause disease

eg. mutation that causes sick cell anemia

Question 6

a mutation that is neutral

Answer 6

A neutral mutation can have an effect on the amino acid sequence, but does not effect the functioning of a protein and are usually termed silent mutations

eg. silent mutation

Question 7

Why is silent mutation, an example of a neutral mutation

Answer 7

A silent mutation is an example of a neutral mutation because it does not change the amino acid sequence of the protein that is produced.

Question 8

Why is sickle cell anemia an example of a deleterious mutation

Answer 8

A single nucleotide change in the β-globin gene leads to abnormal hemoglobin, causing red blood cells to sickle. This impairs blood flow and results in health issues like pain and anemia.

Question 9

why is the mutation for lactose intolerance and hiv resistance, an advantageous mutation

Answer 9

The lactose tolerance mutation allows adults to digest lactose by maintaining lactase enzyme production, while the CCR5-Δ32 mutation provides resistance to HIV by preventing the virus from entering immune cells.

Question 10

causes of mutations

Answer 10

mutations can be caused by mutagens such as UV rays, X rays, chemicals or spontaneously

mutations can be inherited through mutations to th germline

Question 11

what causes genetic variation between species

Answer 11

mutation

Question 12

All genetic variation between species is a result

Answer 12

of a mutation

Question 13

The evolutionary significance of mutations is

Answer 13

the ability to create new alleles, increasing genetic diversity in a population

Question 14

Mutations can change the frequency of existing alleles by

Answer 14

by competing for space and resources for them

Question 15

The effect of mutations on allele frequencies

Answer 15

Mutations introduce new alleles to a gene pool
Passing this down to offspring will increase the allele frequency and overtime may replace another allele if it is beneficial.

Question 16

Point mutations

Answer 16

Changes to one nucleotide in a gene due to substitution, point mutations can be classified as silent, missense and nonsense

Question 17

Silent mutations

Answer 17

One nucleotide is substituted for another. The gene still codes for the same amino acid sequence and no effect on the protein

Question 18

Missense mutation

Answer 18

One nucleotide is substituted for another resulting in a difference sequence of amino acids. A different protein is produced

Question 19

Nonsense

Answer 19

One nucleotide is substituted and now codes for STOP. Protein is not functional

Question 20

compare the effect of substitution to a nucleotide of point mutations

Answer 20

Silent mutation-Substitution to a nucleotide that has no effect on the amino acid sequence. This is due to degeneracy of the genetic code.

Missense mutation-Substitution to a nucleotide that results in a difference amino acid. This results in an altered primary protein structure

Nonsense mutation-Substitution to a nucleotide that results prematurely ending translation due to a codon becoming the STOP codon. Protein is shorter than the regular protein. and protein is not functional

Question 21

types of mutations

Answer 21

point mutation
silent mutation
block mutation

Question 22

frame shift mutation

Answer 22

Involves the addition or deletion of one or two nucleotides. This results in a ‘shift’ in how the DNA strand is read

Amino acid sequence changes which also results in a change in protein.

Question 23

frameshift mutations examples

Answer 23

Cystic fibrosis, Crohn’s disease and certain types of cancers are due to frameshift mutations

Crohn’s disease can be associated with frameshift mutations in the NOD2 gene, where insertions or deletions of nucleotides shift the reading frame of the gene, resulting in a nonfunctional protein that disrupts immune system regulation.

Cystic fibrosis is often caused by frameshift mutations in the CFTR gene, such as the ΔF508 deletion, which leads to a misfolded cystic fibrosis transmembrane conductance regulator protein and impairs chloride ion transport across cell membranes.

Question 24

Frameshift mutation(insertion) vs frame shift mutation(deletion)

Answer 24

frameshift muttion insertion hasAddition of one or two nucleotides which alter the reading frame of the following nucleotides. Whereas, frameshift mutation deletion has Deletion of one or two nucleotides which alter the reading frame of the following nucleotides.

Question 25

Block mutation

Answer 25

a mutation involving the altering of the structure of a chromosome by inserting, deleting or swapping a cluster of nucleotides during meiosis, hence block mutations can impact mutiple genes

Question 26

What are examples of chromosomal abnormalties

Answer 26

Aneuploidy- occurs when an individidaul has an extra chromsome or one missing thier their karyotype

Polyploidy occurs when an individaul has more than 2 sets of chromsomes–when this occurs in humans, zygote is unable to survive, but when this occrus in plants the phenotype of the plant will be altered

Question 27

allele what is it

Answer 27

pair of genes that occupy a specific location on a particular chromosome and control the same trait

Question 28

mutagen

Answer 28

Anything that can cause a mutation

Question 29

what are mutations caused by

Answer 29

Mutations can be caused by a mutagen like radiation or it can occur randomly,

Question 30

how does a random mutation occur

Answer 30

changes in the nucleotide sequence of DNA that occur without pattern and introduce new variation into a population.

Question 31

Do all mutations pass on

Answer 31

no some mutations do not pass on because some people cnanot have children

Question 32

when will a mutation be heritable and when will a mutation be non heritable

Answer 32

a mutation can occur in both somatic cells nad germline cells but mutations can only occur in germline cells because germline cells are reporudctive cells hence mutatiosn can be passed onto offspring in only germline cells.

Question 33

Degeneracy

Answer 33

Refers to the concept that Multiple codons code for the same amino acid.

Question 34

unambiguous

Answer 34

one codon codes for only single amino acids and are specific

Question 35

universal

Answer 35

refers to the concept that almost every organism uses the same codons to code for the same amino acid.

Question 36

what happens when there is a change in the amino acid sequence

Answer 36

it can lead to a defective protein

Question 37

What happens when a mutation occurs that DOESNT change the amino acid sequence

Answer 37

this will have a neutral effect, known as a silent mutation

Question 38

Sickle cell anemia is problematic as the person affected by it will have less oxygen. However, when they are infected by malaria, this mutation can be helpful. Applying your knowledge of immunity, why do you think this mutation is helpful in those who are infected.

Answer 38

the sickle cell shape allows immunecells to identiyfthat the cell is infected quicker to laucnh an immune response

Question 39

How does having heterozygous sickle cell anemia affect a person’s susceptibility to malaria compared to someone with normal red blood cells?

Answer 39

In heterozygous sickle cell anemia, both normal and sickle-shaped red blood cells are present. Sickle cells are more easily recognized and destroyed by immune cells when infected with malaria, offering some protection. In people with only normal red blood cells, the infected cells are harder for immune cells to detect and eliminate.

Question 40

What happens to people with homozygous sickle cell anemia when they get malaria?

Answer 40

n homozygous, they only have sickle cells which means a lot of these cells are affected and thus most of them are killed by the immune system. however, they do not have normal red blood cells to supply oxygen and all the sickle cells are alos being killed so less oxygen -> more likely going to die regardless of whether they are infected or not

Question 41

explain chromosomal insertion, inversion and translocation in BLOCK MUTATIONS

Answer 41

Chromosomal insertion: A segment of one chromosome is inserted into another chromosome or into a different location on the same chromosome (block mutation).
Inversion: A segment of a chromosome is reversed end to end (block mutation).
Translocation: A segment of one chromosome is transferred to another chromosome (block mutation).