1. Reproduction Unit
An Introduction
Biology I

2. Definition
What is reproduction?
Simply, making more of an organism.

3. Asexual vs Sexual
What is the difference between asexual and sexual reproduction?
Asexual – one parent gives DNA
Sexual – two parents give DNA
Q: Which is it if a woman goes to a sperm bank and becomes pregnant? (Sexual)

4. Types of Asexual Reproduction
Binary fission: Single- celled organism splits in two
Ex. bacteria

5. Types of Asexual Reproduction
Budding—a bud (small replica) grows off the side of the parent and breaks off to form an independent organism
Yeast
hydra

6. Types of Asexual Reproduction
Fragmentation and regeneration—a multicellular organism splits and each fragment regenerates missing body parts to form complete organisms
Planaria
Sea stars

7. Asexual Reproduction
Regeneration – which of these is forming a whole, new organism and which of these is simply replacing a lost body part?

8. Asexual Reproduction
Regeneration – more examples

9. Asexual Reproduction
Plants - cloning
Asexual – one source of DNA

10. Asexual Reproduction
Mitosis
Cell Division
Used for Growth

11. Sexual Reproduction
2 sources of genetic material

12. Sexual Reproduction Fusion (joining) of two gametes, or sex cells
The moment when egg and sperm (both sex cells) fuse is called fertilization
The joined egg and sperm are called a zygote (a single cell)
Sexual reproduction
Fusion of haploid gametes – form a zygote
Female – ovum Male is spermatozoon
Advantage of large egg and small sperm
Advantage of Sex – GENETIC VARIATION
Parthenogenesis – unfertilized egg develops through mitosis – is haploid – male honey bee
Also the whiptail lizards – complex form of parthenogenesis in which the chromosomes double – to make diploid zygotes – all females
Hermaphorditism – each sex has both male and female parts – very efficent –
Sequential hermaphrodism – when an individual reverses it’s sex –
Protogynous – female first (doesn’t make sense to be male till your big enough to protect your group)
Protandrous – male first (females are bigger to hold more eggs)