Sexual Reproduction in Animals

Male and female reproductive system

1.1 Female reproductive system

External genitals Internal reproductive organs

1.1.2a Female internal reproductive organs

6) Ovary

5) Fallopian tubes

6) Ovary4) Uterus

2) Vagina

3) Cervix

1.1.2b Female internal reproductive organs

4) Fallopian tube

5) Ovary

6) Pubic bone

3) Uterus

2) Cervix

1) Vagina

1.2.1 What is the function of the vagina?

10cm long, 2.5cm wide Thin walled passage leading from vulva

to cervix Receives the penis during sexual

intercourse At the end of pregnancy, it acts a birth

canal

1.2.5 What is the function of the uterus / womb?

Pear-shaped structure with thick muscular wall

Accepts fertilised ovum which becomes implanted into the uterine lining

Accommodates, nourishes and protects the embryo and foetus during pregnancy

1.2.6 What is the function of the oviduct / fallopian tubes?

Muscular tube lined with cilia (hair-like structures) and mucus-secreting cells

Helps to transfer ova from ovary into the uterus

Site of fertilisation (normally)

1.2.7 What is the function of the ovaries?

Consist of Graffian follicles which develop into female gametes

Produce female sex hormones such as oestrogen and progesterone

Think about this

What is ectopic pregnancy? Fertilized ovum is implanted

Fallopian tube Cervix Ovaries Abdomen

Ectopic pregnancy

2.1 Male reproductive system

External genitals Internal reproductive organs

2.2a Male internal reproductive organs

2) Erectile tissue

3) Testis

4) Epididymis 5) Vas deferens

6) Cowper’s gland

7) Prostate gland

8) Seminal vesicle

1) Urethra

2.3.1 What is the function of the penis?

Latin word for ‘tail’ Muscular erectile organ Consists of spongy tissue containing

blood spaces and blood vessels Introduces semen into the vagina of

female during sexual intercourse

2.3.2 What is the function of the scrotum?

Pouch of skin containing the testes Found outside the main body cavity

at a temperature slightly lower than body temperature, which is optimum for sperm production

The testis

2.3.3 What is the function of the testes?

Testes (plural) / Testis (singular) Each consists of hundreds of tiny

sperm tubules (seminiferous tubules)

Produce sperm Produce male sex hormone

testosterone

3.1 What is the difference between a sperm and an ovum?

3.2 Structure of sperm and ovum

1) Head

2) Middle piece

3) Tail

A) Nucleus

B) Cytoplasm

C) Mitochondria

2) Plasma membrane 3) Cytoplasm

1) Protein coat 4) Nucleus

5) Nucleolus6) Chromosomes

3.3 Number produced

Sperm Millions of sperm released at each

ejaculation

Ovum Usually one ovum is released once in

about 28 days

3.4 Size

Sperm Much smaller than ovum

Ovum Much larger than sperm

3.5 Size of nucleus and cytoplasm

Sperm Small nucleus and little cytoplasm

Ovum Large nucleus and abundance of

cytoplasm

3.6 Mobility

Sperm Mobile Energy produced by mitochondria Activity nourished by seminal fluid

Ovum Immobile Moved along the oviduct by sweeping action of

cilia and peristaltic contractions of walls of oviduct