Reproductive System

Question 1

gonads

Answer 1

Both sexes in humans have
a set of gonads where gametes are produced,
ducts for gamete transport, and
structures for copulation.

Question 2

Ovaries

Answer 2

Ovaries contain follicles that
develop eggs and
produce sex hormones.

Question 3

ovulation

Answer 3

An immature egg is ejected from the follicle in a process called ovulation.

Question 4

Oviducts

Answer 4

Oviducts (Fallopian tubes) convey eggs to the uterus where a fertilized egg develops.

Question 5

uterus

Answer 5

The uterus opens into the vagina through the cervix.

Question 6

The vagina

Answer 6

The vagina
receives the penis during sexual intercourse and
forms the birth canal.

Question 7

Testes

Answer 7

Testes (singular, testis) produce
sperm and
male hormones.

Question 8

epididymis

Answer 8

The epididymis stores sperm as they develop further.

Question 9

Several glands contribute to semen. These are the

Answer 9

seminal vesicles,
prostate gland, and
bulbourethral glands.

Question 10

During ejaculation

Answer 10

sperm is expelled from the epididymis,
seminal vesicles, prostate, and bulbourethral glands secrete into the urethra
semen is formed and expelled from the penis.

Question 11

Sperm production

Answer 11

is regulated by a negative feedback system of hormones and
involves the
hypothalamus,
hormones of the anterior pituitary (LH and FSH), and
testes (Leydig cells and Seminiferous tubules, respectively).

Question 12

Spermatogenesis

Answer 12

occurs in seminiferous tubules.

Question 13

Primary spermatocytes

Answer 13

are formed by mitosis and

divide by meiosis I to produce secondary spermatocytes.

Question 14

Secondary spermatocytes

Answer 14

divide by meiosis II to produce round spermatids,
spermatids differentiate into elongate sperm, and
mature sperm are released into seminiferous tubules.

Question 15

Oogenesis

Answer 15

begins when a diploid cell in a developing follicle begins meiosis.
Each month about one primary oocyte resumes meiosis.
A secondary oocyte arrested at metaphase of meiosis II is ovulated.
Meiosis of the ovum is completed after fertilization.

Question 16

Oogenesis and spermatogenesis are

Answer 16

alike in that both produce haploid gametes but
different in that
oogenesis produces only one mature egg and two polar bodies that degenerate and……..
spermatogenesis produces four mature gametes.

Question 17

About every 28 days

Answer 17

the hypothalamus signals the anterior pituitary to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH),
which trigger the growth of a follicle and ovulation, the release of an egg.

Question 18

FSH

Answer 18

FSH targets the follicles, drives growth of the follicle and production on estrogen and an oocyte.

Question 19

LSH

Answer 19

targets the corpus luteum and drives production of progesterone.

Question 20

After ovulation,

Answer 20

the ruptured ovarian follicle heals over as the corpus luteum.

Question 21

The corpus luteum

Answer 21

mostly secretes progesterone, which
stimulates the endometrium to thicken,
prepares the uterus for implantation of the embryo, and
inhibits the hypothalamus, reducing LH secretion.

Question 22

If the egg is fertilized

Answer 22

the embryo releases hormones that maintain the uterine lining and
menstruation does not occur.

Question 23

If the egg is not fertilized

Answer 23

the drop in LH shuts down the corpus luteum and its hormones,
menstruation is triggered, and
the hypothalamus and pituitary stimulate development of a new follicle.

Question 24

Embryonic development

Answer 24

begins with fertilization,
the union of sperm and egg,
to form a diploid zygote.

Question 25

Sperm are adapted to reach and fertilize an egg

Answer 25

Sperm have
a flagellum comprised of microtubules,
many mitochondria in the midpiece, which provide ATP for tail movements, and
a head that contains a haploid nucleus and is tipped with an acrosome containing enzymes that help it penetrate the egg.

Question 26

During fertilization,

Answer 26

sperm squeeze past follicle cells,
acrosomal enzymes digest the egg’s jelly coat,
a sperm binds to egg receptors,
sperm and egg plasma membranes fuse,
the sperm nucleus enters the egg cytoplasm,
The vitelline layer separates and becomes impenetrable, and
the egg and sperm nuclei fuse.

Question 27

Cleavage

Answer 27

is a rapid series of cell divisions that produces
more cells,
smaller cells, and
a fluid-filled embryo called a blastula.

Question 28

gastrulation

Answer 28

During gastrulation
cells migrate to new locations,
a rudimentary digestive cavity forms, and
the basic body plan of three layers is established with
ectoderm outside—becomes skin and nervous systems,
endoderm inside—becomes digestive tract,
mesoderm in the middle—becomes muscle and bone.

Question 29

Organs develop

Answer 29

from the three embryonic layers.

Question 30

notochord

Answer 30

The stiff notochord forms the main axis of the body and is later replaced by the vertebral column in most chordates.

Question 31

neural tube

Answer 31

The neural tube develops above the notochord and will become the
brain and
spinal cord.

Question 32

As the embryo elongates, paired somites

Answer 32

form along the sides of the notochord,
hollow out to form a coelom (body cavity located between the intestinal canal and the body wall), and
eventually contribute to muscles, bone, and other connective tissues.
Other systems develop at the same time.

Question 33

Tissues and organs develop by

Answer 33

changes in cell shape,
cell migration, and
programmed cell death (also called apoptosis).

Question 34

Pattern formation,

Answer 34

the emergence of the parts of a structure in their correct relative positions,
involves the response of genes to spatial variations of chemicals in the embryo, and
results in tissues and organs developing in their proper positions at the correct times.

Question 35

gestation

Answer 35

Pregnancy, or gestation, is the carrying of developing young within the female reproductive tract.

Question 36

Human pregnancy

Answer 36

averages 266 days (38 weeks) from fertilization or
40 weeks (9 months) from the start of the last menstrual period.

Question 37

Human development begins

Answer 37

with fertilization in the oviduct (fallopian tubes).

Question 38

blastocyst

Answer 38

Cleavage produces a blastocyst whose
inner cell mass becomes the embryo and the
trophoblast, the outer cell layer, which
attaches to the uterine wall and
forms part of the placenta.

Question 39

Gastrulation

Answer 39

occurs and organs develop from the three embryonic layers.

Question 40

4 extraembryonic membranes develop

Answer 40

The amnion
The yolk sac,
The allantois
The chorion

Question 41

The amnion

Answer 41

surrounds the embryo and

forms a fluid-filled amniotic cavity that protects the embryo.

Question 42

The yolk sac,

Answer 42

in humans, does not store yolk but is a source of the first blood cells.

Question 43

The allantois

Answer 43

contributes to the umbilical cord,

forms part of the urinary bladder, and

Question 44

The chorion

Answer 44

contributes to the placenta and

secretes human chorionic gonadotropin (HCG), which prevents menstruation in mammals.

Question 45

The placenta

Answer 45

is a
close association of 
embryonic chorion and
mother’s blood vessels, and
site of
gas exchange—from mother to embryo,
nutrient exchange—from mother to embryo, and
waste exchange—from embryo to mother.

Question 46

The first trimester

Answer 46

is the period of greatest change.
The embryo forms, looking like other vertebrate embryos.
Extraembryonic membranes form.
All major organ systems are established.
After 9 weeks from fertilization, the embryo is called a fetus and
can move its arms and legs and
starts to look distinctly human.

Question 47

During the second trimester,

Answer 47

there is a great increase in the size of the fetus, and
human features are refined.
At 20 weeks (140 days), the fetus - is about 7.6 inches….and
- weighs about 1 lb.

Question 48

The 3rd trimester is a time of rapid growth

Answer 48

The circulatory and respiratory systems mature.
Muscles thicken and the skeleton hardens.
The third trimester ends with birth.
Babies born as early as 24 weeks may survive only with extensive medical care.

Question 49

Hormonal changes induce birth.

Answer 49

Estrogen makes the uterus more sensitive to oxytocin and growing fetus stretches uterus.
Oxytocin acts with prostaglandins to initiate labor.
The cervix dilates to about 10 cm.
The baby is expelled by strong uterine contractions.
The placenta dislodges and is expelled after the baby.