Prenatal development

Question 1

first 2 weeks after conception

Answer 1

germinal period

Question 2

ball of about 100 cells formed by about 1
week following conception

Answer 2

blastocyst

Question 3

in the blastocyst, the outer layer of cells,
which will go on to form structures that
provide protection and nourishment to the
embryo

Answer 3

trophoblast

Question 4

in the blastocyst, the inner layer of cells,
which will go on to form the embryo

Answer 4

embryonic disk

Question 5

fluid-filled membrane that surrounds and
protects the developing organism in the
womb

Answer 5

amnion

Question 6

in the womb, gatekeeper between mother
and fetus, protecting the fetus from bacteria
and wastes in the mother’s blood, and
producing hormones that maintain the blood
in the uterine lining and cause the mother’s
breasts to produce milk

Answer 6

placenta

Question 7

structure connecting the placenta to the
mother’s uterus

Answer 7

Umbilical cord

Question 8

weeks 3–8 of prenatal development

Answer 8

embryonic period

Question 9

in prenatal development, elapsed time since
conception

Answer 9

gestation

Question 10

in the embryonic period, the outer layer of
cells, which will eventually become the skin,
hair, nails, sensory organs and nervous
system (brain and spinal cord)

Answer 10

Ectoderm

Question 11

in the embryonic period, the middle of the
three cell layers, which will become the
muscles, bones, reproductive system and
circulatory system

Answer 11

mesoderm

Question 12

in the embryonic period, the inner layer of
cells, which will become the digestive system
and the respiratory system

Answer 12

endoderm

Question 13

in the embryonic period, the part of the
ectoderm that will become the spinal cord
and brain

Answer 13

neural tube

Question 14

cell of the nervous system

Answer 14

neuron

Question 15

in prenatal development, the period from
week 9 until birth

Answer 15

fetal period

Question 16

one of the three 3-month periods of prenatal
development

Answer 16

trimester

Question 17

at birth, babies are covered with this oily,
cheesy substance, which protects their skin
from chapping in the womb

Answer 17

vernix

Question 18

The _______form from the inner layer of the embryonic disk.

Answer 18

digestive and respitory systems

Question 19

During the _________period of prenatal development, nearly all
the major organs are formed.

Answer 19

embryonic

Question 20

behaviour, environment or bodily condition
that can have damaging influence on prenatal
development

Answer 20

teratogen

Question 21

sexually transmitted infection caused by HIV,
resulting in damage to the immune system

Answer 21

AIDS (acquired immune deficiency
syndrome)

Question 22

set of problems that occur as a consequence
of high maternal alcohol use during
pregnancy, including facial deformities, heart
problems, misshapen limbs and a variety of
cognitive problems

Answer 22

fetal alcohol spectrum disorder (FASD)

Question 23

genetic disorder due to carrying an extra
chromosome on the 21st pair

Answer 23

down syndrome

Question 24

involving a combination of genetic and
environmental factors

Answer 24

multifactorial

Question 25

a permanent alteration of a DNA sequence that makes up a gene

Answer 25

genetic mutation

Question 26

prenatal procedure in which a needle is used to withdraw amniotic fluid containing fetal cells from the placenta, allowing possible prenatal problems to be detected

Answer 26

amniocentesis

Question 27

prenatal technique for diagnosing genetic problems, involving taking a sample of cells at 5–10 weeks gestation by inserting a tube into the uterus

Answer 27

chorionic villus sampling (CVS)

Question 28

prenatal test that involves the pregnant mother giving a blood sample to test for increased risk for chromosomal abnormalities in the fetus, including Down syndrome

Answer 28

non-invasive prenatal testing

Question 29

Keisha has inherited one recessive gene for the sickle-cell trait along with one normal dominant gene. As a result of this ________, she is resistant to malaria and does not have sicklecell anaemia.

Answer 29

incomplete dominance

Question 30

Who has the greatest risk of developing haemophilia, which is an X-linked recessive disorder?

Answer 30

A male who has one X chromosome that contains the gene for this disorder.

Question 31

What is the term for the limited potential developmental possibilities established by genes?

Answer 31

reaction range

Question 32

John is short for his age and is very coordinated. Although exposed to a variety of activities, none has particularly interested him. His father, who used to wrestle when he was younger, signs John up for wrestling, thinking this could be the perfect sport. He convinces John to give it a try and John goes on to become a champion wrestler. This is an example of ________.

Answer 32

passive genotype → environment effects

Question 33

Gametes are _________.

Answer 33

egg and sperm cells

Question 34

During the embryonic period, the ______

Answer 34

major organs develop

Question 35

A child who has an X0 chromosomal make-up (where 0 denotes a missing chromosome where there is supposed to be a 23rd pair) will most likely _____.

Answer 35

be a female who will later experience problems in the development of the reproductive system