Genetics, Populations, Evolution And Ecosystems

Question 1

Genotype

Answer 1

Genetic constitution of an organism

Question 2

Phenotype

Answer 2

The expression of this genetic constituent and its interaction with the environment

Question 3

What are alleles and how do they arise?

Answer 3

• Variations of a particular gene on the locus
• Arise by mutation

Question 4

Multiple alleles

Answer 4

Occurs due to mutations in a gene that occur at different positions in the gene

Question 5

Codominant alleles

Answer 5

Both alleles are equally dominant and equally expressed in the phenotype

Question 6

Explain how autosomal linkage affects inheritance of alleles

Answer 6

• two genes located on same autosome
• so alleles on the same chromosome inherited together
• stay together during independent segregation of homologous chromosomes during meiosis
• but crossing over between homologus chromosomes can create new combination of alleles
• if the genes are closer together on an autosome, they are less likely to be split by crossing over

Question 7

Evolution

Answer 7

• change in allele frequency over time in a population
• occurring through process of natural selection

Question 8

Community

Answer 8

• all the population of different species living in the same place at the same time

Question 9

Ecosystem

Answer 9

• a community and the non living components of its environment

Question 10

Niche

Answer 10

• the specific role of a species within its habitat
• governed by its adaptation to both abiotic and biotic conditions

Question 11

Carrying capacity

Answer 11

• the maximum population size of a species that an ecosystem can support