lecture 1: intro

Question 1

Why study reproduction?

Answer 1

• fundamental to life
• farming
• fascinating
• fun
• future of human civilisation

Question 2

What are patterns of reproduction?

Answer 2

• asexual

* sexual

Question 3

How can asexual reproduction occur?

Answer 3

• fission e.g. bacterial cell
• budding e.g. hydra
• parthenogenesis e.g. aphids, whiptail skink, reproduce by activating eggs and creating new individuals from the egg alone, no sperm involved
• no exchange of genetic information - clonal

Question 4

What are the main features of sexual reproduction?

Answer 4

• exchange of genetic information
• bacteria etc - can exchange genetic material, conjugation
• 2 sexes - female/male + ?
• female – eggs – large –> embryo
• male – sperm: small, motile
• meiosis vs mitosis
• variation is a fuel for evolution

Question 5

What are variations on a theme?

Answer 5

• hermaphrodites, comes from greek mythology,
• parthenogenesis
• protogyny, protandry

Question 6

What selective pressures may favour evolution of protandry vs protogyny?

Answer 6

Protrandry is the condition in which an organism begins life as a male and the animal changes into a female

Protogynous hermaphrodites refer to organisms that are born female and at some point in their lifespan change sex to male. As the animal ages, based on internal or external triggers, it shifts sex to become a male animal.

• making eggs you need to be big as they are big cells
• maybe advantage in that you only reproduce when you are big enough

Question 7

What is the relationship between sex and the echiuroid worm Bonellia?

Answer 7

Echiuroid worm - Bonellia
• female worm is rock dwelling
• male lives inside the female’s uterus and fertilises her eggs
• if larva lands on sea floor becomes female
• larva will enter females mouth, migrate to the uterus and differentiate into a male
• female is about 1m long

Question 8

What are rates of pregnancy, birth and abortion per 1000 women aged 15-19 in USA in year 2000?

Answer 8

• pregnancies: 83.9
• births: 47.7
• abortions: 24.0

Question 9

What is the world population growth?

Answer 9

• less than 1% north america, europe, russia, australia, NZ
• 1-2% brazil, argentina, chile, china, india, indonesia
• 2-3% many countries in central america, africa, PNG, Asia
• more than 3% many countries in Africa and Asia

Question 10

What are demographic patterns?

Answer 10

• rapid growth in e.g. kenya, nigeria, saudi arabia with higher numbers of 0-14 than 15-44, higher than 45-85+ = pyramid
• slow growth: US, Aus, Canada, 0-14 ~= 15-44 and not much greater than 45-85+
• zero growth: denmark, Austria, Italy: 0-14 = 15-44 and not far off 45-85
• negative growth: germany, bulgaria, hungary: more older than younger

Question 11

What proportion of Australian couples who want to have children require medical intervention to conceive?

Answer 11

• 1 in 6
• male = 30%
• female = 30%
• combined = 10%
• other = 5%
• unexplained = 25%

Question 12

Where does the majority of human seminal fluid come from?

Answer 12

• seminal vesicle
• prostate
• testes

Question 13

Is testosterone important for female reproduction?

Answer 13

• yes
• precursor for oestrogen
• likewise oestrogen is important for male reproduction

Question 14

How many days is pregnancy in humans?

Answer 14

• ~270
• mice: 21 (?)
• sheep: 145
• bandicoots: 11-12

Question 15

What is parturition?

Answer 15

Birth