BIOLOGICAL CONSEQUENCES OF CHANGING ALLELE FREQUENCIES

What is the gene pool in a population with high genetic diversity like

• has a large number of alleles for each gene

What characteristics do populations with high genetic diversity tend to have

• large in size

• have gene flow with other populations' gene pools.

Why is genetic diversity important for populations

• It allows populations to be resilient to environmental changes

• Provides a higher chance that some individuals are adaptable and survive.

How does increased genetic diversity affect the chances of extinction

• brings more variation into a population and reduces the chance of extinction

What are the potential biological consequences of increased genetic diversity

• may lead to the addition of new alleles that can cause genetic disorders

Give an example of a genetic disorder introduced through increased genetic diversity

• The cystic fibrosis allele introduced into Australian populations, a recessive genetic disorder affecting the mucus lining of the lungs

What does decreased genetic diversity lead to

• limited variation in a population

• making organisms more vulnerable to changes in selective pressures

• thereby increasing the chance of extinction

What can greatly affect the genetic diversity of a population

• Different events and various mechanisms that affect allele frequencies

What do large populations retain

• high genetic diversity

What are the consequences of high genetic diversity in populations

• higher adaptive capacity

• potential for long-term survival

• high resilience

What happens to genetic diversity in small, isolated populations

• lose genetic diversity

What are the consequences of low genetic diversity in populations

• lower adaptive capacity

• weak potential for long-term survival

• low resilience

What happens if a female cheetah mates with multiple males

• Variability among the cubs is high\

• the chance that all cubs will be susceptible to a new pathogen is low

What happens if a female cheetah mates with one male

• Variability among the cubs is low

• the chance that all cubs will be susceptible to a new pathogen is high

What usually happens to genetic diversity during natural selection and why

• Decreased

• During natural selection, a particular phenotype has a selective advantage, so particular alleles become more common, while others are removed

What usually happens to genetic diversity due to gene flow and why?

• Increased

• Usually, the movement of alleles results in new alleles coming into a population

What usually happens to genetic diversity due to genetic drift and why

• Decreased

• Random chance events may lead to a loss of alleles in a population

What usually happens to genetic diversity during a bottleneck event and why

• Decreased

• An event leading to the death of many members of a population may lead to a loss of alleles in a population.

What usually happens to genetic diversity due to the founder effect and why

• Decreased

• A population is descended from individuals with limited diversity in their genetic material

What usually happens to genetic diversity due to mutations and why

• Increased

• Mutations are the source of new alleles, increasing diversity in a population

What is the consequence of small populations with limited or no gene flow on genetic diversity

• They generally have low genetic diversity

How does smaller population size affect inbreeding and genetic diversity

• It increases the rate of inbreeding, which further reduces genetic diversity

What is the impact of low genetic diversity on a population's adaptability

• It limits the population's ability to adapt to changing environmental conditions

Why are populations with low genetic diversity more vulnerable

• They are more susceptible to disease and becoming extinct

Through which mechanisms can low genetic diversity occur in the wild

• Through genetic drift mechanisms like the bottleneck effect and founder effect

How can low genetic diversity occur in domesticated settings

• Due to selective breeding

What does the graph indicate about population size and genetic variation over time

• The graph indicates that while population size can recover after a decline, genetic variation remains persistently low, highlighting a long-term loss in genetic diversity despite population growth.

What does the graph suggest

• Allele frequencies may be lost or fixed over time, resulting in decreased diversity.

• While this shows a gradual change, the loss or fixation of an allele through genetic drift can be quite sudden

What event caused the Australian humpback dolphin to experience a bottleneck effect

• An El Niño event between 1250 and 3750 years ago caused a warming of the dolphin's habitat, leading to a sudden decrease in its population size

What are the consequences of the bottleneck effect on the Australian humpback dolphin

• The species is listed as vulnerable due to low genetic diversity and limited gene flow between its populations

When did cheetahs experience a bottleneck, and what was the consequence

• Cheetahs experienced a bottleneck approximately 10,000 years ago, dramatically reducing their numbers and leading to inbreeding in the remaining small population

How does the genetic diversity of cheetahs compare to species with good genetic diversity

• Species with good genetic diversity have around 20% variation in their alleles, while the cheetah population has only 1% variation

What are the consequences of limited genetic variation in cheetahs

• caused a number of harmful mutations

• reproductive challenges for male cheetahs

• lethal genetic disorders

What is genetic diversity

• Genetic diversity is the amount of genetic variation in a population’s gene pool

Why is high genetic diversity beneficial for populations

• Populations with high genetic diversity have a greater chance of successfully adapting to changing environments

Why are populations with low genetic diversity at risk

• Populations with low genetic diversity are less likely to adapt to changing environments and are more likely to become vulnerable to extinction

What is antigenic drift?

• Antigenic drift is when a point mutation alters a virus’ nucleic material, resulting in small changes so that it continues to be recognized and reacted to by the body’s immune system

What is antigenic shift?

• Antigenic shift is when two or more strains of a virus combine to form a new strain with antigens from each of the original strains