SCI1186 Lecture Notes - Lecture 6: Prostate, Daphnia, Parthenogenesis
16 Jun 2018
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Week 6 – Reproduction
TYPES OF REPRODUCTION
3 types:
1. Asexual: when new individuals form from a single parent. This process occurs through mitosis, where cells
divide to grow or maintain an individual or create a new individual. This occurs through fission, budding or
fragmentation.
2. Sexual: occurs in most plants and animals. Uses a diploid zygote
from one parent and Haploid gametes from another parent to fuse
together. This process redistributes parent genes to create a new
individual
3. Parthenogenesis: this process occurs when unfertilized eggs
develop into an individual. Occurs in both vertebrates and
invertebrates
a. Invertebrates:
i. Occurs in aphids, daphnia, bees, wasps and
ants when the haploid egg nucleus undergoes
mitosis without cytokinesis (splitting of
cytoplasm)
ii. In bees, this process loads to the production of
only male bees
iii. Aphids and daphnia alternate between
parthenogenesis and sexual reproduction
(asexual during good conditions, sexual during
poor conditions)
b. Vertebrates:
i. Occurs in some fish, amphibians and lizards
ii. Includes 2 nuclei fusing together to form a diploid nucleus (Australian gecko)
Fission: the act of splitting one parent into two or more individuals (anemone)
Budding: when a new individual grows out from the parent. This occurs by a bud forming on the body of an
individual and develops into a new individual (Cnidarian)
SEX ORGANS
2 types:
1. Primary
a. Gonads: used to produce hormones and gametes, either ovaries or testes
2. Secondary
a. Glands: used to aid gametes and house ducts (prostate gland)
Document Summary
3 types: asexual: when new individuals form from a single parent. This process occurs through mitosis, where cells divide to grow or maintain an individual or create a new individual. This occurs through fission, budding or fragmentation: sexual: occurs in most plants and animals. Uses a diploid zygote from one parent and haploid gametes from another parent to fuse together. This process redistributes parent genes to create a new individual: parthenogenesis: this process occurs when unfertilized eggs develop into an individual. Fission: the act of splitting one parent into two or more individuals (anemone) Budding: when a new individual grows out from the parent. This occurs by a bud forming on the body of an individual and develops into a new individual (cnidarian) 2 types: primary, gonads: used to produce hormones and gametes, either ovaries or testes, secondary, glands: used to aid gametes and house ducts (prostate gland)
