Transcript Packet13.ppt

Packet 13
Human Reproduction and
Development
Aim: How does the structure of the human reproduction system relate to its
functions?
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(A) SEXUAL
REPRODUCTION

Reproduction is the production
of a new offspring
Two types—sexual and
asexual
Sexual reproduction always
involves:
Fertilization: fusion of nuclei of
egg and sperm to form a
zygote
Development: growth of the
zygote into a new individual
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Fertilization can be either internal or external

Internal—fertilization
occurs inside the female
body—fewer eggs because
there is a better chance of
survival

External—fertilization
occurs outside the body in
the environment—common
in aquatic plants and
animals—eggs and sperm
are released directly into
the water—risky so there
are large numbers of eggs
and sperm released
(B) SEXUAL DEVELOPMENT

Reproductive system is the
only system in the human body
in which the organism can still
lead a healthy life if it is not
used or working properly

First 6 weeks of
development—males and
females are identical

7th week in which the primary
reproductive organs develop
Gonads=reproductive organs

Males—testes—
produce testosterone

Females—ovaries—
produce estrogen

Production of the hormones
determine whether the embryo will
develop physically into a male or
female
(C) MALE REPRODUCTIVE
SYSTEM

main function is to
produce and deliver
sperm
STRUCTURE

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Testes—primary male reproductive organ—
produces testosterone
Scrotum—sac that contains the testes
Seminiferous tubules: tiny tubules where
sperm is produced
Epididymis: where sperm matures and is
stored

Vas deferens: extends into the abdominal cavity
where it meets with the urethra

Urethra: tube that leads outside the body through
the penis

Seminal vesicle, prostate gland and bulbourethral
gland—produce seminal fluid—semen—2.5 million
sperm per drop
SPERM STRUCTURE

Head—contains the nucleuscontains _______

Midpiece—contains
mitochondria for __________

Tail—used to propel the sperm
towards the egg