8.02 Genetics and Prenatal Development

Question 1

condensed strands of DNA located in the nucleus of the cell

Answer 1

chromosome

Question 2

science of heredity

Answer 2

genetics

Question 3

section of DNA that codes for a protein

Answer 3

gene

Question 4

how many chromosomes do humans have?

Answer 4

46; 23 from mom and 23 from dad

Question 5

22 chromosome pairs that code for most traits

Answer 5

autosomes

Question 6

1 chromosome pair that code for male or female

Answer 6

sex chromosomes

Question 7

a gene that will fade into the background, when paired with a more dominant gene

Answer 7

recessive gene

Question 8

human traits are controlled by many genes

Answer 8

polygenic inheritance

Question 9

occurs when a child inherits 2 recessive genes–one from each parent

Answer 9

recessive genetic disorders

Question 10

a treatable inability to break down phenylalanine which results in brain damage

Answer 10

phenylketonuria (PKU)

Question 11

a blood disorder

Answer 11

sickle-cell anemia

Question 12

respiratory tract disease

Answer 12

cystic fibrosis

Question 13

3 recessive genetic disorders

Answer 13

phenylketonuria (PKU), sickle-cell anemia, cystic fibrosis

Question 14

3 chromosome disorders

Answer 14

Turner’s syndrome, down syndrome, klinefelter’s syndrome

Question 15

XO sex chromosomes, a female who is sexually underdeveloped

Answer 15

Turners syndrome

Question 16

extra chromosome 21, results in intellectual disability and distinct facial features

Answer 16

Down syndrome

Question 17

XXY sex chromosomes, a male with reduced masculine characteristics

Answer 17

Klinefelter’s syndrome

Question 18

single diploid cell (46 chromosomes) that forms from fertilization

Answer 18

zygote

Question 19

2-8 weeks following fertilization; embryo attaches to uterus, organs develop, embryo is vulnerable

Answer 19

embryonic period

Question 20

2 weeks following fertilization; placenta and umbilical cord develop, cell differentiation and specialization begin

Answer 20

germinal period

Question 21

process during which the single-celled zygote divides repeatedly to grow

Answer 21

mitosis

Question 22

joining of egg and sperm cells

Answer 22

fertilization

Question 23

8 weeks to birth: fetus grows and develops, organs function

Answer 23

fetal period

Question 24

times during the embryonic period when environmental influences can have an impact on the developing embryo; mother’s illnesses, toxins, or drugs

Answer 24

critical period

Question 25

any substance (drug, chemical, virus etc.) that can cause a birth defect

Answer 25

teratogen

Question 26

fetal alcohol syndrome (FAS)

Answer 26

caused by alcohol consumption during the critical embryonic period; causes brain damage

Question 27

most likely to occur during the first 3 months of pregnancies; occurs in as many as 20% of pregnancies

Answer 27

spontaneous abortion or miscarriage

Question 28

what causes miscarriages?

Answer 28

most likely caused by a genetic defect, or a problem in fetal development