Asexual Reproduction- involves only one parent, produces a new organism genetically identical to the parent.
Sexual Reproduction- involves the production and fusion of sperm and egg (1 or 2 parents), produces variation in offspring.
Asexual ReproductionOnly 1 Parent-All Kingdoms1. Binary Fission/Mitosis-one cell divides into two cells…
Exponential growth 1 2 4 8 16 32 64 128 256 512
Single celled Eukaryotes- Mitosis (nucleus breaks apart and reforms 2 nuclei in 2 different cells)
2. Budding-offspring begins to develop on the parents body and then fragments off the original parent-Hydra
Figure 46.1 Two from one: asexual reproduction of a sea anemone (Anthopleura elegantissima)
3. Vegetative Propagationproducing new plants from existing vegetative structures,
4. Fragmentationthe body of the parent breaks into distinct pieces, each of which can produce an offspring Sea Stars
6. ParthenogenesisAn unfertilized egg develops into an adult Parthenogenesis: Aphids, honeybees, lizards
7. Spore Formation Are produced by many organisms(algae, fungi, bacteria) Contain DNA, Cytoplasm & tough outer wall-protects it from drying out.
Simple Sexual Reproduction Conjugation: sexual process in some simple organisms in which genetic material is transferred by cell to cell contact. 1. Kingdom Protist: Algae ex: Chlamydamonas • Alternation of generations: both haploid and diploid generations exist
asexual n Sexual conjugation 2n zygospore
Chlamydomonas- (green algae) Reproduces asexually most of the time, it can also reproduce sexually under certain environmental conditions.
2. Kingdom Fungi • Conjugation occurs between different hypha Bread Mold
3. Kingdom Eubacteria: prokaryotes • Not a true form of sexual reproduction • Plasmid: pieces of genetic material transferred from one bacteria to another • Form a connecting bridge of cytoplasm (pilus)
Plant life cycles 2 Stages- alternation of generations. Sporophyte-is the diploid (2n) stage that produces spores by meiosis Gametophyte-is the haploid(n) stage that produces gametes by mitosis (pollen, ovule)
Sexual Reproduction • Pollen production
In the female gametophyte-2 haploid nuclei go to the center-polar nuclei & 1 egg.
Male Gametophyte is in the pollen on the anther. • Female Gametophyte is in the ovule in the ovary.
Parts of a Flower Stigma Petal Style Sepal Filament Anther ovary 8. Structures 1, 3, & 7 make up the structured female structure called the 9. Structures 5 & 6 make up the male structure called the 10. The ovule(s) is found within the 11. Which structure is the site of pollen production? 12. Which structure is the recipient of the pollen? 13. Which structure protects the reproductive parts and attracts pollinators? 14. The structure that will eventually become a fruit is the 15. The structure that holds the anther upright is the 16. Does a plant produce more pollen or more ovules? Explain.
Double Fertilization-1 sperm fertilizes the central cell (future endosperm), other fertilizes the egg (future embryo) Double fertilization
Sexual Reproduction • Female Gametophyte What is 3n? 2n? What part will become food for the new embryo?
Reproduction in Animals • For almost all animals, the organism is always diploid • Only the gametes are haploid
Some animals may be able to reproduce either asexually or sexually, like the sponges. More complex animals, it is sexual reproductionthat is predominant.
Gametes are produced in the sex organs –gonads Sperm is produced in the testes Eggs are produced in the ovaries. Gametes are made through the process of meiosis
Among simpler organisms, both kinds of sex organs develop in the same individual. These animals are called hermaphrodites
Why would separate sexes be an adaptation? MORE VARIETY
Fertilization Sperm + Egg