Section 2: Sexual vs Asexual Reproduction Chapter 7

Reproductive processes that do not involve the union of individuals or gametes. Asexual Reproduction

Occurs in most plants, bacteria, protists, and low invertebrates. One parent! Offspring are identical to the parents. Asexual Reproduction

Easier to reproduce asexually! Requires less energy! Able to reproduce large numbers very quickly in the right environment. Advantages of Asexual Reproduction

Less genetic variation! ◦ Why is this bad?  If there is a negative genetic mutation in the organism  all the offspring will have this mutation, which may be disastrous. Disadvantages of Asexual Reproduction

Regeneration – organism uses cell division to re-grow body parts. Types of Asexual Reproduction

Binary Fission – process by which a parent prokaryotic organism (lacking a nucleus) copies its DNA and splits into two new daughter cells. The daughter cells are identical to their parent cell. Types of Asexual Reproduction

Budding – a form of asexual reproduction that a new organism develops as an outgrowth or bud from another organism. The bud stays attached to the parent and continues to grow until it reaches maturity. Then pinches off. Types of Asexual Reproduction

Vegetative Propagation is a form of asexual reproduction in plants. Different types of vegetative propagation: ◦ Runners ◦ Tubers ◦ Plantlets ◦ Suckers Types of Asexual Reproduction

Runners – stems which grow at the soil surface or just below ground that form adventitious roots at the nodes, and new plants from the buds. Types of Asexual Reproduction

Tubers – plant structures that are used for nutrient storage for winter and dry periods. These structures can develop into new plants under certain conditions. Types of Asexual Reproduction

Cloning - is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Types of Asexual Reproduction

Offspring are a combination of both parents therefore different from each parent. Sexual Reproduction

Variety and/or diversity of offspring (color, shape, size, intelligence, ability, etc…) More able to adapt to environmental change. Advantages of Sexual Reproduction

Sometimes traits needed for survival are not passed on. Energy must be consumed. Much slower. Very few offspring are produced at one time. Mutations can occur. Disadvantages of Sexual Reproduction

Pollination is the sexual reproduction of plants. Male gamete = pollen – produced in anther Female gamete = ovum – produced in ovary Sexual Reproduction in Plants

Male gametes (sperm) produced in the testes. Female gametes (ova) produced in ovaries. After fertilization, a zygote is produced. The zygote develops into an embryo. Sexual Reproduction in Animals