JH-KEADLE Types of Reproduction

We will be focusing on genetic material and how it is passed from parent to offspring. All living things pass on their traits to offspring but there are two different types of reproduction.

Asexual Reproduction vocabulary word! asexual reproduction – one organism produces one or more new organisms that are identical to itself. Most microscopic and unicellular organisms can reproduce asexually. Some plants and animals can use this method.

Examples of Asexual Reproduction binary fission budding spores vegetative propagation

Asexual Reproduction vocabulary word! binary fission – a type of cell division in prokaryotes. A parent cell splits into two.

Asexual Reproduction vocabulary word! budding – a bud forms on the parent organism. Once it is big enough, it detaches.

Asexual Reproduction vocabulary word! spores – a specialized cell that can survive in harsh conditions. The parent organism releases spores which can be carried to other locations.

Asexual Reproduction vocabulary word! vegetative propagation – asexual reproduction by some plants where a new plant grows from the stem, roots or leaves of the parent plant.

Asexual Reproduction Parent (tall) Tt offspring (tall) Tt

Sexual Reproduction vocabulary word! sexual reproduction – two parents are required and each contributes a sex cell (sperm or egg). Half of the genes in the offspring come from each parent. The offspring are not identical to the parent. There is more genetic diversity.

Sexual Reproduction vocabulary word! sperm– male sex cell that contains half of the male’s chromosomes. egg– female sex cell that contains half of the female’s chromosomes. Example – humans have 46 chromosomes (23 pairs). The mother contributes 23 and the father contributes 23 to equal 46.

Sexual Reproduction vocabulary word! fertilization – when a sperm and egg join together.

Fertilization (combined genetic material) Sexual Reproduction Parent (tall) Tt Parent (tall) Tt Fertilization (combined genetic material) offspring (tall) TT offspring (tall) Tt offspring (tall) Tt offspring (short) tt

Aesexual Sexual Only requires one parent No sharing of genetic material Offspring is identical to parent No diversity Requires two parents Genetic material is combined The offspring are different from either parent There is diversity

Create this table in your notes: Type of Reproduction Disadvantages Advantages Sexual Asexual * more genetic diversity * can adapt and change * easier to evolve * expend energy looking for a mate * length of gestation * usually occurs faster * don’t have to find a mate * reduces genetic mutations * no new genetics * no diversity * limited evolution Create this table in your notes:

Using both strategies Some organisms can reproduce both ways depending on the conditions they are living in.

Parthenogenesis Organisms that can reproduce asexually and sexually The female can give birth without a male aphids snails some plants hammerheads starfish Kimodo dragon

Hermaphroditic Reproduction Organisms that can reproduce asexually and sexually they have male and female sex organs or they can switch sexes snails slugs most plants some fish earthworms