Reproduction 19/02/2016. Asexual Reproduction. Budding: Types of asexual reproduction: SEXUAL VS. ASEXUAL

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Ross Barnett
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Asexual Reproduction Reproduction SEXUAL VS.

cells which are clones of the parent Types of asexual

into a new organism that separates from the parent. Eg.

1 Asexual Reproduction Reproduction SEXUAL VS. ASEXUAL One parent cell divides by mitosis to produce 2 daughter cells which are clones of the parent Types of asexual reproduction: Budding: 1. Budding 2. Binary Fission 3. Spore Production 4. Fragmentation 5. Parthenogenesis An outgrowth on the parent organism develops into a new organism that separates from the parent. Eg. Yeast, hydra Yeast budding Hydra budding Binary fission A one celled organism splits to form two new cells Example: Bacteria Bacteria fission 1

Spore production Fragmentation Haploid cells that grow into a gametophyte.

Each piece is able to form a new organism.

eggs, female aphids are able to reproduce by parthenogenesis - they give birth to smaller versions of

Sexual Reproduction ASEXUAL REPRODUCTION Method which does not involve the exchange of genetic material

2 Spore production Fragmentation Haploid cells that grow into a gametophyte. Fungi Mosses Moss life cycle Pieces of the parent organism break off and are dispersed. Each piece is able to form a new organism. House plants grow from cuttings Sponges Parthenogenesis Through mitotic cell division, offspring are produced from unfertilized eggs. Some insects balsam wooly adelgid some reptiles, fish In botany, called apomixis As well as laying eggs, female aphids are able to reproduce by parthenogenesis - they give birth to smaller versions of themselves (all female) without the need for fertilization. Asexual vs. Sexual Reproduction ASEXUAL REPRODUCTION Method which does not involve the exchange of genetic material Produces offspring identical to their parent Common in bacteria, protists, some animals SEXUAL REPRODUCTION New individuals are produced by the fusion of haploid gametes Diploid zygotes produced Benefits for genetic variation among offspring Enhances the chances of population s survival Found in most living organisms 2

Sexual Reproduction Flowering Plants FLOWERING PLANTS (ANGIOSPERMS) Flower: reproductive organ of an angiosperm.

in the ovules, tiny chambers in the ovary of the flower Fertilization leads to the production of seeds, contained within the fruit (ripened ovary)

of the: Stigma Style Ovary Pistil (carpel) Stamen Female reproductive structure of a flower; includes Stigma Style Ovary The parts of the female

Ovary bottom part of the pistil. It produces eggs inside chambers called ovules.

3 Sexual Reproduction Flowering Plants FLOWERING PLANTS (ANGIOSPERMS) Flower: reproductive organ of an angiosperm. Reproductive structures are found in flowers Male sex cells are contained in pollen, produced in the anthers of flowers Female sex cells are found in the ovules, tiny chambers in the ovary of the flower Fertilization leads to the production of seeds, contained within the fruit (ripened ovary) Reproductive Structures in Angiosperms Male reproductive organ is the stamen made of: Anther Filament Female Reproductive organ is the pistil made of the: Stigma Style Ovary Pistil (carpel) Stamen Female reproductive structure of a flower; includes Stigma Style Ovary The parts of the female pistil are: Stigma sugary, sticky top surface of the pistil. It receives pollen. Style long, middle portion of the pistil. Ovary bottom part of the pistil. It produces eggs inside chambers called ovules. The male reproductive structure of a flower; includes: Filament Anther Anther the top of the stamen. It produces haploid pollen grains. Filament the long stalk that supports the anther. Pollen grain a protective structure that protects the male sperm of a flowering plant. 3

Pollen grain Each pollen grain has two sperm nuclei inside it.

Pollen grain Pollen grains contain two nuclei: Generative nucleus: which

Tube nucleus: will form a pollen tube down through the style of the pistil to

Pollination Pollen is transferred from the anther to the stigma Two types:

Cross-Pollination Between flowers on different plants Fertilization in a

Sugar secreted by stigma stimulates the tube nucleus to form a pollen tube 3.

Generative nucleus enters the pollen tube 5.

4 Pollen grain Each pollen grain has two sperm nuclei inside it. One is called the tube nucleus. The other is called the generative nucleus. Pollen grain Pollen grains contain two nuclei: Generative nucleus: which divides to produce two sperm nuclei will fertilize the egg. Tube nucleus: will form a pollen tube down through the style of the pistil to reach the ovary. Pollination Pollen is transferred from the anther to the stigma Two types: Self-Pollination Within the same flower, or between flowers of the same plant Cross-Pollination Between flowers on different plants Fertilization in a Flowering Plant 1. Pollen lands on the stigma 2. Sugar secreted by stigma stimulates the tube nucleus to form a pollen tube 3. Pollen tube pushes its way to the ovary and enters an ovule 4. Generative nucleus enters the pollen tube 5. Generative nucleus divides by mitosis to produce a second sperm nucleus. 6. First sperm fertilizes the egg 7. Second sperm fuses with ovule to form the endosperm 8. Ovule will become a seed with a tiny plant embryo and an endosperm food supply Fertilization & Seed Development 4

Monocots vs Dicots Some angiosperms are monocots others are dicots Monocots and dicots refer to the number of seed leaves present Monocots one seed

5 Monocots vs Dicots Some angiosperms are monocots others are dicots Monocots and dicots refer to the number of seed leaves present Monocots one seed leaf; Dicots two seed leaves Monocot seeds stores most of their food in the endosperm Dicot seeds store most of their food in the cotyledons (seed leaves) 5

BIOLOGY 3201 REPRODUCTION

BIOLOGY 3201 REPRODUCTION Asexual vs. Sexual Reproduction MODES OF REPRODUCTION (1) Asexual one parent cell divides into two by mitosis to produce 2 identical cells which are clones of the parent (2) Sexual