Asexual and Sexual Reproduction Objective: Students will explain asexual (binary fission, budding, vegetative, mitosis) and sexual reproduction (angiosperms, mammals)

Asexual Reproduction Process by which a single parent reproduces by itself without the joining of gametes (reproductive cells) Sexual Reproduction Process by which male and female gametes unite to produce the first cell of a new organism

Asexual Reproduction Examples: –Spore Formation –Binary Fission –Vegetative Reproduction –Regeneration –Budding –Mitosis Does not involve meiosis or the joining of haploid gametes Cells are diploid (2N) Produces offspring that are genetically identical to the parent

Spore Formation Spores - (“mummified” bacterium) – dormant non-reproductive body Protective coating encase key parts of the bacterium Spores formed by certain bacteria in response to harsh environmental conditions Spore able to survive for weeks (even years) through drought, heat, even radiation When conditions become more favorable, bacterium “comes to life” (transforming from a spore back to a cell) Also produced by certain fungi, algae, and non-flowering plants.

Binary Fission (p. 475) One cell splits into two cells Offspring are genetically identical to parent Occurs in Prokaryotes (organisms w/out a nucleus) i.e. Bacteria

Vegetative Reproduction Also called vegetative propagation Process by which new plant "individuals" arise or are obtained without production of seeds or spores (without sexual reproduction)plantseedsspores produce new plants from existing vegetative structures by cutting from stems, leaves, roots, parts of leaves and thick canes

Budding Formation of a new organism by the protrusion of part of another organism. Very common in plants and fungi (vegetative Reproduction), but may be found in animal organisms, as well. Shortly, the new organism will break away from parent and live independently New organism is genetically identical to the primary one (a clone)clone A new hydra budding from an existing hydra Budding Yeast

Regeneration Form of tissue repair and/or healing Ability to regrow lost limbs, severed nerve connections, damaged tissues and organs Example of plant regeneration - when grass is cut, the blade regrows Starfish Planaria

Mitosis Mitosis produces two cells with the same number of chromosomes as the parent cell. Mitosis of a diploid cell (2n) produces two diploid daughter cells.chromosomes

Sexual Reproduction Process by which male and female gametes unite to produce the first cell of a new organism Involves the joining of haploid gametes that have been produced by meiosis Offspring are not genetically identical to either parent

Sexual Reproduction In Mammals Reproduce by internal fertilization (male deposits sperm inside the reproductive tract of the female – where fertilization occurs) Meiosis used to produce the gametes: sperm and egg In Angiosperms (Flowering Plants) Meiosis used to produce the spores -- which in time will produce the gametes (pollen -male; egg - female) Reproduce by cross- pollination (transfer of pollen to female reproductive structure)

Angiosperms (CH 24-1, pp ) Flowering plant that produces seeds within an ovary that develops into a fruit; therefore, the seeds are covered Most abundant plant on Earth Terrestrial and lack locomotion –Poses a problem –Gametes are delicate single cells. For two plants to cross-pollinate, there must be a mechanism for the two gametes to reach each other safely

Reproductive Parts of a Flower The flower is the reproductive organs of angiosperms Stamen - male organ that produces pollen (consists of the anther & filament)Stamen Carpel (also called pistil) – female organ that produces eggCarpel Other parts of the flower –Sepal – green (resemble leaves) protect the flower while it’s developing –Petal – often brightly colored – attract pollinators (i.e. insects) to flower Most angiosperm flowers contain both the stamen and pistil

Active Art phschool.com webcode cbp-7241 Active Art phschool.com webcode cbp-7241 (click the link to go to activity) Answer the questions. What is the function of flowers? An angiosperm is a plant that produces seeds that are enclosed in a _______________. The male structure of a flower is known as the _______________. The female structure of a flower is known as the _______________. List the structures that make up the stamen. List the structures that make up the carpel. Describe the function of petals on a flower. Where does meiosis take place? Where does pollination take place?

Life Cycle of an Angiosperm