Chapter 3

Question 1

Zygote

Answer 1

One-celled organism resulting from fertilization

Question 2

Fertilization

Answer 2

Union of sperm and ovum to produce a zygote

Question 3

Assisted reproductive technology (ART)

Answer 3

Methods used to achieve conception through artificial means

Question 4

Dizygotic twins

Answer 4

Twins conceived by union of two different ova with two different sperm cells (fraternal)

Question 5

Monozygotic twins

Answer 5

Twins resulting from the division of a single zygote after fertilization (identical)

Question 6

Polygenic inheritance

Answer 6

Pattern of inheritance in which multiple genes at different sites on chromosomes affect a complex trait

Question 7

Multifactorial transmission

Answer 7

Combination of genetic and environmental factors to produce certain complex traits

Question 8

Epigenesis

Answer 8

Mechanism that turns genes on or off and determines functions of body cells

Question 9

Incomplete dominance

Answer 9

Pattern of inheritance in which a child receives two different alleles resulting in partial expression of a trait

Question 10

Sex-linked inheritance

Answer 10

Pattern of inheritance in which certain characteristics carried on the X chromosome inherited from the mother are transmitted differently to her male and female offspring

Question 11

Genetic counseling

Answer 11

Clinical service that advises prospective parents of their probable risk of having children with hereditary defects

Question 12

Behavioral genetics

Answer 12

Quantitative study of relative hereditary and environmental influences on behavior

Question 13

Concordant

Answer 13

Term describing tendency of twins to share the same trait or disorder

Question 14

Reaction range

Answer 14

Potential variability, depending on environmental conditions, in the expression of a hereditary trait

Question 15

Canalization

Answer 15

Limitation on variance of expression of certain inherited characteristics

Question 16

Genotype-environment interaction

Answer 16

The portion of phenotypic variation that results from the reactions of genetically different individuals to similar environmental conditions

Question 17

Genotype-environment correlation

Answer 17

Tendency of certain genetic and environmental influence to reinforce each other; may be passive, reactive, or active

Question 18

Passive correlation

Answer 18

Inherited environments from parents

Question 19

Reactive correlations

Answer 19

Children with differing genetic makeups evoke different reactions from others

Question 20

Active correlations

Answer 20

Selecting or creating experiences consistent with their genetic tendencies

Question 21

Niche-picking

Answer 21

Tendency of a person to seek out environments compatible with their genotype

Question 22

Nonshared environmental effects

Answer 22

Unique environment in which each child grows up, consisting of distinctive influences or influences that affects one child differently than another

Question 23

Temperament

Answer 23

Characteristic disposition, or style of approaching and reacting to situations

Question 24

Gestation

Answer 24

Period of development between conception and birth

Question 25

Gestational age

Answer 25

Age of an unborn baby, usually dated from the first day of an expectant mother's last menstrual cycle

Question 26

Cephalocaudal principle

Answer 26

Principle that development proceeds in a head-to-tail direction; upper parts develop before the lower parts of the trunk

Question 27

Proximodistal priniple

Answer 27

Principle that development proceeds from within to without; parts near the center develop before the extremities

Question 28

Germinal stage logistic

Answer 28

First 2 weeks of prenatal development

Question 29

Germinal stage characteristic

Answer 29

Rapid cell division, blastocyst formation, and implantation in the wall of the uterus

Question 30

Implantation

Answer 30

Attachment of the blastocyst to the uterine wall, occurring at about day 6

Question 31

Embryonic stage logistic

Answer 31

Second stage of gestation (2-8 weeks)

Question 32

Embryonic stage characterization

Answer 32

Rapid growth and development of major body systems and organs

Question 33

Spontaneous abortion

Answer 33

Natural expulsion from the uterus of an embryo that cannot survive outside the womb

Question 34

Fetal stage logistics

Answer 34

Final stage of gestation (8 weeks to birth)

Question 35

Fetal stage characteristics

Answer 35

Increased differentiation of body parts and greatly enlarged body size

Question 36

Teratogen

Answer 36

Environmental agent, such as a virus, a drug, or radiation, that can interfere with normal prenatal development and cause developmental abnormalities

Question 37

Acquired immune deficiency syndrome (AIDS)

Answer 37

Viral disease that undermines effective functioning of the immune system