genetics end of topic

Question 1

Gene pool

Answer 1

All the alleles available to a population

Question 2

Genetic variation

Answer 2

The differences in dna amongst individuals in a population

Question 3

Genetic frequency

Answer 3

The percentage (proportion) of each allele in a gene pool.

Question 4

DNA

Answer 4

DNA is a chemical that carries genetic instructions (as a code formed by the sequence of bases in DNA). DNA is stored as chromosomes inside the nucleus of a cell.

Question 5

2 sources of genetic variation

Answer 5

Mutations and sexual reproduction

Question 6

Negatives of inbreeding

Answer 6

Inbreeding depression: the loss of fitness and strength of a population which is mainly caused by inbreeding and the inheritance of the same recessive harmful alleles. When the relatives mate, the offspring may inherit two copies of the same recessive harmful allele and suffer the consequences of expressing the harmful allele.
2. Reduced genetic diversity: Only certain individuals with specific alleles are chosen to reproduce. Certain alleles are lost to the population, which removes variation. Natural selection works upon variation, so this may put the survival of the population at risk if a new disease or environmental change occurs. For example, in Kakapo, limited genetic variation means that the population is less adaptable to new diseases or environmental changes. A single disease outbreak could devastate the entire species.
3. Unintended Traits: Focusing on specific traits can inadvertently amplify undesirable ones. For instance, breeding for rapid growth in livestock may result in joint problems or reduced fertility.

Question 7

Inbreeding

Answer 7

The mating of 2 closely related individuals.

Question 8

Cloning

Answer 8

Cloning is the process of creating a genetically identical copy of a DNA, cell or an organism.

Question 9

Negatives of cloning

Answer 9

Genetic biodiversity A cloned population lacks genetic diversity compared with other populations as they are all identical. If the environmental conditions change, they are less likely to survive, especially the introduction of a new pathogen.
Evolution of populations Any population derived from a clone will have little or no genetic diversity. This greatly increases the risk of ‘re-extinction’. Cloning also does not address the problems that put the species in danger in the first place, such as habitat destruction and hunting.
Health or survival of individuals If the genome of the cloned individual contains alleles for genetic disorder, all the clones inherit this disorder. Cloned organisms often suffer from defects, shorter lifespans, and developmental issues.
Low Success Rates: Cloning is inefficient, with a high failure rate and high costs.

Question 10

Founders effect

Answer 10

Founder effect occurs when a small number of individuals from a larger population establish a new, isolated population.

Question 11

Bottle neck effect

Answer 11

Bottleneck effect occurs when there is a significant reduction in population size due to an environmental event or human activity

Question 12

DNA sequencing

Answer 12

DNA sequencing is the process of identifying the exact order of the bases in a DNA strand.