Unit A Reproduction

CHAPTER
4
Review
Human Reproduction
Key Ideas
Male and female humans have specialized
organs to produce gametes and to ensure
fertilization.
• Males produce sperm, the male gametes,
in the testes. Females produce eggs, the
female gametes, in the ovaries.
• Fertilization of an egg by a sperm cell
happens in the female’s oviduct.
The zygote develops in the uterus.
It takes nine months for a human zygote
to develop into a baby.
• In the first trimester, the embryo becomes
a fetus and the placenta forms. In the
second trimester, limbs and facial features
develop. In the third trimester, all the
organ systems continue developing and
the fetus continues to gain mass.
• During birth, rhythmic contractions
of the uterus push the baby out of the mother.
The placenta is pushed out shortly after.
• The zygote and the cells created from the
first few cell divisions are unspecialized
stem cells. Stem cells can form into any
type of specialized cell.
Vocabulary
puberty, p. 108
testosterone, p. 108
scrotum, p. 109
testes, p. 109
seminiferous tubules, p. 109
epididymis, p. 109
vas deferens, p. 109
urethra, p. 109
penis, p. 109
semen, p. 110
mammary glands, p. 112
ovary, p. 112
follicles, p. 112
estrogen, p. 112
progesterone, p. 112
menstrual cycle, p. 113
menopause, p. 113
ovulation, p. 113
corpus luteum, p. 113
oviduct (fallopian tube), p. 113
Sex chromosomes determine the gender of the offspring.
• The X and Y chromosomes control
whether an individual is male or female:
an XX combination produces a female
and an XY combination produces a male.
• The X and Y chromosomes also control
sex-linked characteristics such as red-green
colour blindness and having hemophilia.
140 Unit A Reproduction
NEL