Ch. 3 Vocab

Question 1

chromosomes

Answer 1

strings of genetic material in a nuclei of cells

Question 2

gametes

Answer 2

cells that unite at conception (ova in families; sperm in males)

Question 3

zygote

Answer 3

a single cell created when sperm and ovum unite

Question 4

deoxyribonucleic acid (DNA)

Answer 4

chemical material the marks up chromosomes and genes

Question 5

genes

Answer 5

pieces of genetic material that control or influence traits

Question 6

gonads

Answer 6

sex glands (ovaries in females; testes in males)

Question 7

genotype

Answer 7

the unique genetic blueprint of each individual

Question 8

phenotype

Answer 8

an individual’s particular set of observed characteristics

Question 9

dominant-recessive pattern

Answer 9

patter of inheritance in which a single dominant gene influences apron’s phenotype but two recessive genes are necessary to produce an associated trait

Question 10

polygenic inheritance

Answer 10

a pattern of inheritance in which many genes influence a trait

Question 11

multifactorial inheritance

Answer 11

inheritance affected by both genes and the environment

Question 12

cephalocaudal pattern

Answer 12

growth that proceeds from the head downward

Question 13

proximodistal pattern

Answer 13

growth that proceeds from the middle of the body outwards

Question 14

germinal stage

Answer 14

the first stage of prenatal development, beginning at conception and ending at implantation (approximately 2 weeks)

Question 15

implantation

Answer 15

attachment of the blastocyst to the uterine wall

Question 16

placenta

Answer 16

a specialized organ that allows substances to be transferred from mother to embryo and from embryo to mother, without their blood mixing

Question 17

umbilical cord

Answer 17

an organ that connects the embryo to the placenta

Question 18

amnion

Answer 18

a fluid-filled sac in which the fetus floats until just before it is born

Question 19

embryonic stage

Answer 19

the second stage of prenatal development, from week 2 though week 8, during which the embryo;s organ systems form

Question 20

neurons

Answer 20

specialized cells of the nervous system

Question 21

organogenesis

Answer 21

the process of organ development

Question 22

fetal stage

Answer 22

the third stage of prenatal development, from week 9 to birth, during which growth and organ refinement take place

Question 23

viability

Answer 23

the ability of the fetus to survive outside the womb

Question 24

cell body

Answer 24

the part of a neuron that contains the nucleus and is the site of vial cell functions

Question 25

synapses

Answer 25

tiny spaces across which neural impulses flow from one neuron to the next

Question 26

axons

Answer 26

taillike extensions of neurons

Question 27

dendrites

Answer 27

branch-like protrusions from the cell bodies of neurons

Question 28

glial cells

Answer 28

the "glue" that holds neurons together to give form to the structures of the nervous system

Question 29

teratogens

Answer 29

substances, such as viruses and drugs, that can cause birth defects

Question 30

anoxia

Answer 30

oxygen deprivation experienced by a fetus during labor and/or delivery

Question 31

neonate

Answer 31

term for babies between birth and 1 month of age

Question 32

low birth weight (LBW)

Answer 32

newborn weight below 5.5 pounds