Chapter 2 Lifespan Questions

The heritability of specific traits and behaviors refers to the extent to which variation among people on a given characteristic is due to _____.

Genetic Differences

What is the process that may be done before conception to help prospective parents determine the risk that their children will inherit genetic defects and chromosomal abnormalities?

Genetic counseling

The range of reaction refers to _____.

the variety of potential expressions of a genetic trait, depending on environmental opportunities and constraints

Females are more likely to display X-linked genetic disorders because they have two X chromosomes.

False

Identical twins who share 100% of their genes are 100% alike.

False

Males have two X sex chromosomes, while females have one X and one Y sex chromosome.

False

Most severe genetic disorders are inherited through dominant inheritance.

False

Women who give birth over the age of 35 are at the same risk for pregnancy and birth complications, including miscarriage and stillbirth, as are younger women.

False

Which of the following terms describes the complex set of hereditary characteristics inherited from our biological parents that constitutes our genetic makeup?

Genotype

A fertilized ovum is also known as a zygote.

True

Different teratogens can cause the same birth defect, and a variety of birth defects can result from the same teratogen.

True

What is a teratogen?

an agent that causes damage to prenatal development

Some genes are passed through dominant-recessive inheritance, in which some genes are always expressed, regardless of the other gene with which they are paired. Other genes follow the pattern of incomplete dominance and will only be expressed if paired with _____.

another recessive gene

Fetal deaths, premature births, and low birthweight are up to twice as frequent in mothers who are _____ than in those who do not _____.

cigarette smokers; smoke cigarettes

Prenatal exposure to abuse of which of the following has been identified as the leading cause of developmental disabilities?

Alcohol

After birth, newborns are routinely screened to assess their immediate health with the _____.

Apgar Scale

What feature appears marking the beginning of the fetal period?

Bone

Match the genetic inheritance pattern with its description. 1.Genes that are dominant are always expressed, regardless of the gene they are paired with, and recessive genes are expressed only if paired with another recessive gene. 2.Both genes influence the characteristic, and aspects of both genes appear. 3.Polygenic traits are the result of interactions among many genes. The expression of a gene is determined by whether it is inherited from the mother or the father.

1. Dominant-recessive inheritance 2. Incomplete dominance 3. Polygenic inheritance 4. genomic imprinting

A human zygote contains how many pairs of chromosomes?

23 pairs

What type of twins are conceived when a woman releases more than one ovum, and each is fertilized by a different sperm?

Dizygotic Twins

SELECT ALL THAT APPLY. Low birth-weight babies are at a higher risk for which of the following?

Down Syndrome respiratory problems neurological difficulties poor growth

Trisomy 21, also known as _____, is the most common chromosome disorder.

Down syndrome

All the organs and major body systems form during the third to eighth week after conception known as the _____.

Embryonic period

Which of the following traits is strongly canalized?

Motor development

Some inborn characteristics are caused by sudden changes and abnormalities in the structure of genes known as _____.

Mutations