Chapter 2

Question 1

Chromosomes

Answer 1

• structures that contain genetic material

- we have 23

Question 2

DNA

Answer 2

the molecule that composes one chromosome and is the biochemical basis of heredity

Question 3

gene

Answer 3

the biochemical instruction that is produced by a group of chemical compounds within a strand of DNA

Question 4

genotype

Answer 4

a person’s complete set of genes

Question 5

phenotype

Answer 5

observable features that result from the interactions between a person’s genes and the environment

Question 6

behavioral genetics

Answer 6

study of the extent to which genetic and environmental differences contribute to difference in traits

Question 7

dizygotic twins

Answer 7

• two zygotes/fertilized ova

- most common

Question 8

monozygotic twins

Answer 8

• one zygote that divides into two individuals

- share genes

Question 9

twin studies

Answer 9

studies of twins, both identical and fraternal, reared apart and together

Question 10

adoption studies

Answer 10

are adopted children more similar to biological parents or to adoptive parents?

Question 11

family studies

Answer 11

studies of siblings with different degrees of genetic similarity and vary environments

Question 12

3 stages of prenatal development

Answer 12

• zygote
• embryo
• fetus

Question 13

conception

Answer 13

• once a month an ovum (female egg)
• moves through fallopian tube to uterus
• uterus is where baby develops during pregnancy
• if not fertilized it disintegrates and is flushed away with menstruation

Question 14

zygote

Answer 14

• month 1
• fertilized egg reaches the uterus and attaches itself to the uterus
• cell multiplication begins
• internal organs and circulatory system begins to form
• cell division takes place at the end of two weeks
• heart begins to beat
• small bumps show beginnings of arms and legs.

Question 15

embryo

Answer 15

• month 2
• all major organ systems develop
• placenta and umbilical cord develop
• amniotic fluid surrounds baby
• face and limbs take shape

Question 16

fetus

Answer 16

• month 3 (longest period)
• nostrils, mouth, lips, teeth buds, and eyelids forms
• arms, legs, fingers and toes are almost complete
• all internal organs present - but aren’t ready to function
• the genital organs can be recognized as male or female

Question 17

lanugo

Answer 17

thick downy hair covering fetus

Question 18

vernix

Answer 18

a protective coating that forms on baby’s skin

Question 19

mother’s nutrition

Answer 19

• balanced diet essential
• proteins, vitamins, and minerals
• increase caloric intake 10-20%

Question 20

Risk factors

Answer 20

• nutrition
• stress
• age
• teratogens

Question 21

teratogen

Answer 21

• an agent that causes abnormal prenatal development

- drugs, disease, environmental hazards.

Question 22

fetal medicine

Answer 22

treating prenatal problems before births

Question 23

genetic engineering

Answer 23

replacing defective genes with synthetic normal ones

Question 24

infant mortality rate

Answer 24

percentage of infants who die before their 1st birthday