Type (asexual or sexual) Organisms that use this type Asexual vs. Sexual Reproduction Please copy this chart in your notebook – use the WHOLE page. Name Type (asexual or sexual) What happens? Organisms that use this type + Positives - Negatives 1. Binary Fission 2. Bacterial Conjugation 3. Fragmentation 4. Budding 5. Pollination 6. Sexual Reproduction

Asexual vs. Sexual Reproduction

Reproduction & Development Selective Forces -- all of evolution is based on reproduction -- to persist through evolutionary time, animals must put copies of their genes into the next generation -- for sexual reproduction, fertilized egg must develop into surviving offspring

Asexual reproduction The primary form of reproduction for single-celled organisms such as archaea, bacteria, and protists. Some plants and fungi may reproduce asexually as well.

Reproduction Asexual reproduction -- no reproductive organs -- only one parent -- no reproductive organs -- no gametes (sex cells) produced -- no fertilization or zygote formation -- offspring are genetically identical to parents (clones)

Asexual Reproduction Advantages - pass on 100% of genome to each offspring - all individuals can produce offspring directly - can occur rapidly - saves energy and resources (no gonads or gametes, no finding mates, no courtship, no STDs)

Asexual Reproduction Disadvantages -- no genetic variation in offspring (except for random mutations) -- limited ability to respond to changing environment

Sexual Reproduction Results in increasing genetic diversity of the offspring. Characterized by two processes: meiosis, halving of the number of chromosomes fertilization, combination of two gametes and the restoration of the original number of chromosomes During meiosis, chromosomes usually cross over = genetic recombination. Primary method of reproduction for the vast majority of visible organisms, including almost all animals and plants.

Sexual Reproduction -- usually involves two parents -- organisms have reproductive organs -- haploid gametes produced by meiosis; fertilization  diploid zygote -- offspring are genetically unique

Sexual Reproduction Advantages -- increased genetic variability in offspring -- ability to respond to changing environment

Sexual Reproduction Disadvantages -- pass only 50% of genome to each offspring -- energy expended for gonads and gametes -- is complicated; occurs more slowly -- requires finding mates, courtship -- STDs

Binary Fission Asexual Cell splits and replicated DNA goes with each part Prokaryotes, Bacteria + Fast and easy - Everybody has the same DNA

Bacterial Conjugation Asexual “Sex” A bacteria shoots out a tube and sends a piece of its DNA to another bacteria Bacteria + Mixes DNA - “Parent” loses a little piece of DNA

Fragmentation/ regeneration Asexual Body of parent breaks and produces offspring Fungi, moss, sea stars, planarian + Easy - Parent broken, same DNA Fragmentation or Clonal Fragmentation is a form of asexual reproduction or cloning where an organism is split into fragments. The splitting may or may not be intentional. Each of these fragments develop into mature, fully grown individuals that are a clone of the original organism. If the organism is split any further the process is repeated. Fragmentation is seen in many organisms such as molds, some annelid worms, and starfish. Binary fission of single-celled organisms such bacteria, protozoa and many algae is a type of fragmentation. Molds, yeast, and mushrooms, all of which are part of the Fungi kingdom, produce tiny filaments called hyphae. These hyphae obtain food and nutrients from the body of other organisms to grow and fertilize. Then a piece of hyphae breaks off and grows into a new individual and the cycle continues. Fragmentation is observed in nonvascular plants as well, liverworts and mosses.

Fragmentation/ regeneration Fragmentation or Clonal Fragmentation is a form of asexual reproduction or cloning where an organism is split into fragments. The splitting may or may not be intentional. Each of these fragments develop into mature, fully grown individuals that are a clone of the original organism. If the organism is split any further the process is repeated. Fragmentation is seen in many organisms such as molds, some annelid worms, and starfish. Binary fission of single-celled organisms such bacteria, protozoa and many algae is a type of fragmentation. Molds, yeast, and mushrooms, all of which are part of the Fungi kingdom, produce tiny filaments called hyphae. These hyphae obtain food and nutrients from the body of other organisms to grow and fertilize. Then a piece of hyphae breaks off and grows into a new individual and the cycle continues. Fragmentation is observed in nonvascular plants as well, liverworts and mosses. Moss

Budding Asexual Offspring grows out of parent Yeast, hydras + Fast, somewhat easy - Same DNA

Pollination Sexual Pollen is delivered to female part of plant Flowering plants + Plants don’t have to move, mixes DNA - Need external source for pollination to take place; wind, bee, bat, butterfly etc.

Pollination

Sexual Reproduction Sexual DNA from 2 individuals merge to form one Animals, Plants + Diverse DNA - Takes a long time, 2 individuals needed