genetic and environmental influences on developmental change

Type A blood is dominant to Type O blood. Is it possible for a man and a woman, each with Type A blood, to have a child that is Type O?

• Yes, if the man is heterozygous.

• Yes, if the woman is heterozygous.

• Yes, if both parents are heterozygous.

• No, it is impossible.

According to Mendel, the traits observed in offspring result from a blending of parental traits. Therefore, a tall pea plant crossed with a short pea plant will produce a pea plant of intermediate height.

• TRUE

• FALSE

The DNA in the skin cells of your hand is significantly different in sequence from the DNA in your liver cells.

• TRUE

• FALSE

How do gene mutations contribute to evolution?

• Beneficial mutations are passed on to several members of a generation, quickly taking hold in a population.

• Unfavorable mutations have a more significant effect on genes than do favorable mutations, so they are spread through the population.

• Natural selection favors beneficial mutations, so they survive and are passed on to future generations.

• Beneficial and unfavorable mutations take hold in the population equally over numerous generations.

Epigenetics is most concerned with:

• Changes in a person’s genotype resulting from environmental influences.

• The expression of a particular gene as influenced by external inputs.

• The expression of a particular gene as influenced by external inputs.

• The heritability of genotypes that have been altered over multiple generations.

Which statement best describes a valid gene—environment interaction on behavior?

• Identical twins adopted by different families often display behaviors typical of their adoptive families.

• In rats, littermates reared by mothers of different strains display the same exploratory behavior as their biological siblings.

• Two people with the same phenotype may not share the same genotype.

• Shrews raised in a lab without their mother fail to nurture their young.

Which confounding variable is teased out when psychologists study the traits of identical twins?

• Shared zygotes of monozygotic twins.

• The influence of dysfunctional alleles.

• Similar environments shared by relatives.

Heritability estimates tell us:

• The rate at which people in a given population develop a particular disorder.

• The degree to which variations in a population can be attributed to genetics.

• The percentage of people who can pass on a specific gene to a child.

• The chance that any one person will carry a particular gene.

Dizygotic twins:

• Rarely resemble each other.

• Grow from separate zygotes.

• Appear to be identical.

• Have identical DNA.

What is the key difference between twin studies and adoption studies (with twins)?

• Twin studies involve identical twins, while adoption studies involve fraternal twins.

• In twin studies, the effects of the environment are not taken into consideration.

• Adoption studies involve non-twin biological siblings raised by different families.

• In adoption studies, twins are separated at birth, adopted, and raised apart.