Booklet 13- Genetic change in populations

Question 1

Define mutations

Answer 1

Mutation is a permanent change in the DNA sequence of genes that leads to the formation of new alleles.

Question 2

When are mutations more detrimental to a population?

Answer 2

Germ-line mutations will pass on to the next generations. Somatic cell mutations will not be passed on.

Question 3

What are point mutations?

Answer 3

Point mutations are changes in the sequence of bases for a single gene.

Question 4

Define redundant

Answer 4

Redundancy/ degeneracy refers to different codons which result in the same amino acid.

Question 5

Define conservative missense mutations

Answer 5

Means the substitution of an amino acid with another amino acid with SIMILAR CHEMICAL PROPERTIES

Question 6

Define NON- conservative missense mutations

Answer 6

Means the substitution of an amino acid with another amino acid with DIFFERENCE CHEMICAL PROPERTIES

Question 7

Define BLOCK mutations

Answer 7

Block mutations are changes to large sections of the chromosome
1. deletion
2.inversion
3. translocation
4. duplication

Question 8

Define polyploidy

Answer 8

inheritance of one or more entire SETS of chromosomes
(triploid, tetraploid)

Question 9

Define aneuploidy

Answer 9

one extra or one less chromosome than the normal diploid or haploid cell

Question 10

How can aneuploidy occur?

Answer 10

1. Meiosis- homologous chromosomes does not occur
2. Meiosis 2- sister chromatids fail to separate

Question 11

State one advantage of genetic diversity

Answer 11

Population with high genetic diversity has a gene pool with a large number of alleles for each gene. This allows population to be RESILIENT to changes in the environment. If there is an environmental change, some individuals will be able to ADAPT to the conditions and SURVIVE.

Question 12

Which agents increase genetic diversity?

Answer 12

1. Mutations
2. Gene flow (emigration and immigration)

Question 13

Which agents decrease genetic diversity?

Answer 13

1. Natural selection
2. Genetic drift
3. Founder effect
4. Bottleneck effect

Question 14

Define selective breeding

Answer 14

Selective breeding is an example of artificial selection where humans choose only those with desirable traits to reproduce.

Question 15

Steps of selective breeding

Answer 15

1. There is variation within population’s gene pool
2. Humans select individuals with desired traits
3. These individuals breed and pass on their alleles to the next generations
4. The alleles that lead to the desires phenotype will be inherited in next generations
   INCREASES THIS PARTICULAR ALLELE FREQUENCY

Question 16

State one advantage of selective breeding

Answer 16

1. Provides improvements to the plants or animals for human use

Plants- increase plant yields which humans can consume

Animals- more meat, increase milk yield

Question 17

State one disadvantage of selective breeding

Answer 17

1. Decrease in genetic variation in plant or animal species and a GENETIC BOTTLENECK

alleles can be lost from the gene pool when only one desired allele/ phenotype is selected for.

Question 18

When can rapid genetic change occur?

Answer 18

Rapid genetic change will occur in species with a short generation time such as bacteria. Much faster replication and reproduction, hence, more mutations along the way.

Question 19

What causes increase in antibiotic resistance in bacteria?

Answer 19

Doctors overprescribing antibiotics, causing more opportunities for bacteria to mutate and change to become resistant.

Patients not finishing a course of antibiotics, some infectious bacteria may survive and be more likely to reproduce and evolve.

Question 20

List the consequences of bacterial resistance.

Answer 20

It becomes more challenging to treat common bacterial infections.
Some serious infections cannot be treated with antibiotics.

Question 21

Define viruses

Answer 21

Viruses are non-cellular pathogen that need a host cell in order to replicate.

Question 22

Define antigenic shift

Answer 22

Occurs when two or more strains of virus combine to form a new strain of the virus with antigens from each of the original strains

Question 23

Define antigenic drift

Answer 23

Point mutations occur in the viral DNA/RNA which changes the ANTIGEN