chapter 3

Question 1

prenatal development takes an average of 38 weeks which are divided into 3 stages

Answer 1

the period of the zygote (weeks 1-2), the period of the embryo (weeks 3-8), the period of the fetus (weeks 9-38)

Question 2

the period of the zygote ends when

Answer 2

the fertilized egg implants itself in the wall of the uterus

Question 3

blastocyst

Answer 3

the fertilized egg four days after conception, which consists of about 100 cells and resembles a hollow ball

Question 4

implantation

Answer 4

the process in which the zygote burrows into the uterine wall and establishes connections with a women’s blood vessels

Question 5

germ disc

Answer 5

a small cluster of cells near the centre of the blastocyst that develops into the baby

Question 6

placenta

Answer 6

the stricter through which nutrients and wastes are exchanged between the mother and the developing child

Question 7

once the blastocyst is completely removed embedded in

Answer 7

the uterine wall, it is called an embryo

Question 8

ectoderm

Answer 8

the outer layer of the embryo, which becomes the hair, outer layer of skin, and nervous system

Question 9

mesoderm

Answer 9

the middle layer of the embryo, which will become the muscles, bones, and circulatory system

Question 10

age of viability

Answer 10

the age at which a fetus can survive because most of its bodily systems function adequately, typically at seven months after conception

Question 11

some fetuses are more active than others and these differences can

Answer 11

predict infants behaviour: an active fetus is more likely than an inactive fetus to be an unhappy, difficult baby

Question 12

three general risk factors

Answer 12

nutrition, stress, a mothers age

Question 13

most pregnant women need to increase their intake of calories by

Answer 13

about 10 to 20 percent to meet the needs of prenatal development

Question 14

spinal bifida

Answer 14

a disorder in which the embryos neural tube does not close properly during the first month of pregnancy (could cause damage to the spinal cord and nervous system)

Question 15

women who report greater anxiety during pregnancy more often

Answer 15

give brith early or have babies who weigh less than average

Question 16

teratogen

Answer 16

an agent that causes abnormal prenatal development

Question 17

pregnant women who smoke are more likely to

Answer 17

miscarry and to bear children who are smaller than average. as children develop, they likely show signs of impaired attention, language, cognitive skills, and behavioural problems

Question 18

fetal alcohol spectrum disorder

Answer 18

a disorder affecting babies whose mothers consumed large amounts of alcohol while they were pregnant

Question 19

children with FAS usually grow

Answer 19

more slowly than average and have heart problems and atypical facial feature

Question 20

moderate drinking can lead to partial fetal alcohol syndrome which refers to

Answer 20

children whose overall physical growth is normal but who have some facial abnormalities and impaired cognitive skills

Question 21

breech presentation

Answer 21

a brith in which the baby’s feet or bottom are delivered before the head

Question 22

hypoxia

Answer 22

lack of oxygen during delivery, typically because the umbilical cord becomes pinched or tangled during delivery