Asexual Reproduction Characteristics of Life: All Organisms Can Reproduce All Organisms Grow and Develop

Sex! 1.Asexual Reproduction a)involves only 1 parent b)offspring genetically identical to parent c)involves regular body cells (somatic) d)its quick with no mate e)Offspring’s genes all come from the same parent without the fusion of egg and sperm 1. Sexual Reproduction a)involves 2 parents b)offspring genetic mix of both parents c)involves specialized sex cells d)its slow e)fusion of two haploid gametes (sperm and egg) to form a diploid zygote

Asexual Reproduction - Characteristics 1.Requires only one parent 2.Offspring have 100% the same chromosomes as the parent. a)Most unicellular organisms reproduce this way. 3.Involves the process of mitosis a)Involves only mitotic cell division = each offspring has exactly the same heredity as its parent. b)Usually rapid compared to sexual reproduction. 3

Types of Asexual Reproduction 1.Binary Fission 2.Budding 3.Regeneration 4.Fragmentation 5.Plant Cuttings 6.Cloning

Asexual Reproduction – Binary Fission 1.Simplest form of asexual reproduction. 2.Happens in bacteria, amoeba, some algae 3.One parent cell splits into 2 (equal halves) identical daughter cells 4.Each daughter cell becomes a new individual

Binary Fission Rod-Shaped Bacterium, hemorrhagic E. coli 2 daughter cells are identical to parent

Asexual Reproduction - Budding 1.Happens in yeast, hydra, corals 2.Parent organism divides into two unequal parts. 3.Parent produces a bud 4.Daughter cell forms from outgrowth or bud off parent 5.Bud gets detached and develops into offspring which is identical to parent

Budding

1.The ability to re-grow lost or damaged body parts. 2.Hydra, planaria, starfish, and earthworm. More complex animals less able to re-grow parts. 3.Crab can re-grow a claw. Some reptiles can re-grow a tail. Most mammals can repair damaged tissue but can not re-grow missing parts. Asexual Reproduction - Regeneration

Regeneration

Humans?

Asexual Reproduction - Fragmentation 1.Fragmentation is a means of asexual reproduction whereby a single parent breaks into parts that regenerate into whole new individuals. 14

Asexual Reproduction – Plant Cuttings 1.Vegetative reproduction is a type of asexual reproduction in plants that relies on multi- cellular structures formed by the parent plant. 1.Vegetative reproduction is a type of asexual reproduction in plants that relies on multi- cellular structures formed by the parent plant. 2.It has long been exploited in horticulture and agriculture, with various methods employed to multiply stocks of plants. 15

Which is Better? It depends! Asexual Reproduction 1.Advantages a)does not require special cells or a lot of energy b)can produce offspring quickly c)in a stable environment creates large, thriving population 2.Disadvantages a)limited ability to adapt (no genetic diversity) b)face massive die-off if environment changes Sexual Reproduction 1. Advantages a)lots of genetic variation within a species b)able to live in a variety of environmental settings c)able to adapt to changes in the environment 2. Disadvantages a)needs time & energy b)produce small populations

Meiosis - SexualMitosis - Asexual Forms sex cells (sperm and eggs) ½ the number of chromosomes compared to the parent cell Genetically identical to parent cell Responsible for growth, differentiation, and asexual reproduction One replication and two divisions One replication and one division 4 daughter cells formed 2 daughter cells formed