Genes and the Environment

Question 1

Nature

Answer 1

in reference to the nature versus nurture debate, refers to the components of an individual’s phenotypes that are determined by his or her genes (e.g., approximately 50% of intelligence is thought to be due to nature)

Question 2

Nurture

Answer 2

refers to the component of one’s phenotypes that are determined by one’s environment

Question 3

Innate

Answer 3

a characteristic one is born with

Question 4

Environment

Answer 4

all non-genetic factors that affect a person’s characteristics (e.g., how he or she was raised, light levels, friends, temperature, good and bad experiences, diet and nutrients available, and so on)

Question 5

Expression

Answer 5

refers to the transcription and translation of the gene to produce the requested protein. Whether or not an allele will be expressed is affected by whether or not the allele is dominant; whether the product is needed by the cell; the stage of the life cycle; and, to some degree, the environmental conditions. In undifferentiated cells, all genes are expressed; in differentiated cells only some genes are expressed.

Question 6

Autosomal recessive

Answer 6

a condition caused by a gene found on an autosome (non-sex chromosome), which only occurs in those with the homozygous recessive genotype

Question 7

Malaria

Answer 7

a disease of warm, wet areas caused by the plasmodiumprotist found in the Anopheles mosquito. When the mosquito bites a person, the plasmodium enters the blood stream and lays its eggs in red blood cells. Sickled red blood cells typical of those people with sickle cell anemia (SCA) are harder for the plasmodium to attack, so those with SCA are less likely to die of malaria. The homozygous recessive condition (ss) confers a disadvantage (SCA) and an advantage (protection from malaria).