Conception & Prenatal Development

Question 1

What’s the name of cell division needed for gametogenesis?

Answer 1

Meiosis

Question 2

Each gamete receives how many autosomes and sex chromosomes?

Answer 2

22 autosomes and 1 sex chromosome

Question 3

__ total chromosomes in new cell when gametes come together

Answer 3

46

Question 4

Name of formation of ova

Answer 4

Oogenesis

Question 5

By what week of gestation will the female fetus have all the ova?

Answer 5

30th week

Question 6

Man or woman determines baby’s sex?

Answer 6

Man gives either X or Y

Question 7

The ovum has the capacity to be fertilized no longer than __ hours after ovulation.

Answer 7

24 hours

Question 8

How long can sperm survive?

Answer 8

1-2 days

Question 9

How long can sperm remain in female tract?

Answer 9

80 hours

Question 10

What happens during the pre-embryonic period?

Answer 10

The zygote enters the uterus and implants in the decidua. 2 weeks after conception.

Question 11

What happens during the embryonic period?

Answer 11

From 3rd week until 8th week. By the end of 8th week, all major organ systems are in place. Teratogens can cause structural damage.

Question 12

What are the three layers of the embryonic disc?

Answer 12

Ectoderm, mesoderm, endoderm

Question 13

When is the fetal period?

Answer 13

9 weeks after gestation. Is now a fetus. Dramatic growth period.

Question 14

What are the major functions of the placenta?

Answer 14

Metabolic, respiratory, and endocrine.

Question 15

Where is the placenta inserted?

Answer 15

Fetal side near center.

Question 16

How heavy is the placenta?

Answer 16

1/6 weight of fetus at birth

Question 17

What are the 2 fetal membranes?

Answer 17

Amnion (inner)

Chorion (outer)

Question 18

What is the purpose of the amniotic fluid?

Answer 18

It cushions the fetus and allows for normal prenatal development. It also maintains stable temperature.

Question 19

How many arteries and veins does the umbilical cord have?

Answer 19

Two arteries and one vein.

Question 20

Describe the course of fetal circulation.

Answer 20

Umbilical arteries carry de-O2 blood from fetal heart to placenta, exchanges oxygen and waste products, back to fetus thru umbilical veins for delivery to fetal tissues

Question 21

Name the three fetal circulatory shunts that bypass fetal liver and lungs.

Answer 21

Ductus venosus, foramen ovale, and ductus arteriosus

Question 22

How long does it take for a zygote to implant in the decidua?

Answer 22

6-10 days. Needs constant estrogen & progesterone to survive.

Question 23

Where in the uterus does the zygote implant?

Answer 23

Upper uterus because it is richly supplied with blood and is thicker.

Question 24

What does the chorion do?

Answer 24

Surrounds the amnion

Question 25

What does the amnion do?

Answer 25

Protects the developing embryo