REPRODUCTION

ASEXUAL REPRODUCTION Reproduction from one organism. Reproduction from one organism. The cell division is mitosis. The cell division is mitosis. The genetic trats are same with the parent organism. The genetic trats are same with the parent organism. Doesn’t effect evolution or variation. Doesn’t effect evolution or variation. Seen in primitive organisms Seen in primitive organisms Only mutations can form variations Only mutations can form variations Monoploid (n) or diploid(2n) organisms can be formed Monoploid (n) or diploid(2n) organisms can be formed Reproduce rapidly Reproduce rapidly

Mitosis Mitosis is important in: Repair and regeneration. Repair and regeneration. Growth Growth Mitosis is a fundamental process for life. During mitosis, a cell duplicates all of its contents, including its chromosomes, and splits to form two identical daughter cells. Mitosis is a fundamental process for life. During mitosis, a cell duplicates all of its contents, including its chromosomes, and splits to form two identical daughter cells. As a result of the mitosis: 2 new cells are formed 2 new cells are formed New cells have same genetic material and chromosome number with mother cell. New cells have same genetic material and chromosome number with mother cell. The genetic material and chromosome number of the new cells are same. The genetic material and chromosome number of the new cells are same.

Mitosis Interphase: Resting period of the cell. Cell carries out normal activities. Interphase: Resting period of the cell. Cell carries out normal activities. Prophase: DNA of the cell replicates itself. 2 sister chromatids are formed Prophase: DNA of the cell replicates itself. 2 sister chromatids are formed Metaphase: Chromosomes with sister chromatids stay in the middle of the cell (equator). Metaphase: Chromosomes with sister chromatids stay in the middle of the cell (equator). Anaphase: Sister chromatids separate from each other and go to the opposite poles. Anaphase: Sister chromatids separate from each other and go to the opposite poles. Telophase: Chromatids reach to the poles and nuclear membrane is formed Telophase: Chromatids reach to the poles and nuclear membrane is formed

Asexual reproduction types 1. Division(binary fission)

2. Budding Young organism is formed from the body of the existing organism. Yeast cells, hydra

3. Sporing ( fungi, algae, plasmodium,, fern, moss) 3. Sporing ( fungi, algae, plasmodium,, fern, moss) Spores(n) gametophyte plant(monoploid) gametes fertilization diploid plant (2n) (meiosis) Spores(n) gametophyte plant(monoploid) gametes fertilization diploid plant (2n) (meiosis) Moss, ferns, fungi and plasmodium Spores are different from gametes. They are seen in asexual reproduction. Forms new individual by germination.

4. Vegetative reproduction The parent plant grows runners and forms new plant. They are typically same. Strawberry, onion, violet, potato

5. REGENERATION The parts which are cut off the plant or animal can form a new organism or an organ. Starfish, earthworm, lizard. But some animals can not produce new organism just form the organ or heal the wound. The parts which are cut off the plant or animal can form a new organism or an organ. Starfish, earthworm, lizard. But some animals can not produce new organism just form the organ or heal the wound.

SEXUAL REPRODUCTION Reproduction from 2 parents. (one forms sperm, the other forms egg) Reproduction from 2 parents. (one forms sperm, the other forms egg) Major Division is meiosis and the major process is fertilization. Major Division is meiosis and the major process is fertilization. Newly formed organisms have new traits different from the parents and the other new organisms. Newly formed organisms have new traits different from the parents and the other new organisms. Sexual reproduction enhance evolution and variation. Sexual reproduction enhance evolution and variation. These variations help organisms to survive better. These variations help organisms to survive better. Can be seen in higher organisms like animals and plants. Can be seen in higher organisms like animals and plants. The reasons for the genetic variations are: meiosis (crossing over, chromosomal lining in the metaphase), fertilization and mutations. The reasons for the genetic variations are: meiosis (crossing over, chromosomal lining in the metaphase), fertilization and mutations. Newly formed organisms are diploid(2n) Newly formed organisms are diploid(2n) It is a long and slow process. It is a long and slow process.

Meiosis Meiosis is important in: formation of gametes (sperm, egg) formation of gametes (sperm, egg) reducing chromosome number reducing chromosome number genetic variation genetic variation As a result of the meiosis: 4 new cells are formed 4 new cells are formed New cells can have different genetic makeup from the mother cell New cells can have different genetic makeup from the mother cell New cells have half of the chromosome number of the mother cell.(n) New cells have half of the chromosome number of the mother cell.(n) The genetic makeup of the new cells can be different from each other. The genetic makeup of the new cells can be different from each other.

Meiosis Prophase I: DNA replicates itself and forms a new DNA molecule. Homologous chromosomes exchange genes (crossing over) Prophase I: DNA replicates itself and forms a new DNA molecule. Homologous chromosomes exchange genes (crossing over) Metaphase I: Homologous chromosomes (tetrad) line up in the middle of the cell(equator). Spindle fibers attach to the chromosomes. Anaphase I: Homologous chromosomes separate from eachother and go to the opposite poles. Telophase I: Chromosomes reach to the opposite poles. Two cells are formed. he chromosome number is reduced by meiosis I. Prophase II: The chromosomes become shorter and thicker. Metaphase II: Spindle fibers attach to the chromatids of the chromosomes. Anaphase II: Sister chromatids of the chromosomes are separated and go to the opposite poles of the cells. Telophase II: Totally 4 cells are formed. Each cell can have a different genetic make up and half of chromosome number

Mitosis and meiosis MITOSISMEIOSIS 1. takes place in body cells. 1. takes place in germ cells and forms sex cells. 2. No crossing over (gene Exchange) 2. crossing over can happen. 3. It has 1 cycle of the phases (1 division) 3. It has 2 cycle of phases(2 division) 4. Produces 2 cells 4. Produces 4 cells 5. newly formed cells have the same chromosome number of the parent cell 5. Newly formed cells have the half of the chromosome number of the parent cell 6. The genetic make up of the newly formed cells are same with each other and with the parent cell 6. The genetic make up of the newly formed cells can be different from each other and from the parent cell

ISOGAMY 2 Gametes of the same morphological structure unite. 2 Gametes of the same morphological structure unite. algae algae HETEROGAMY 2 gametes of different morphological gametes unite. There is a structural difference between sperm and egg but not too much. 2 gametes of different morphological gametes unite. There is a structural difference between sperm and egg but not too much. Algae, fungi Algae, fungi 2 gametes wqith 2 different structures unite. The sizes of the gametes are very different from each other. human 2 gametes wqith 2 different structures unite. The sizes of the gametes are very different from each other. human

SPECIAL REPRODUCTION TYPES 1. CONJUGATION This process is seen in bacteria, paramecium and green algae. 2 individuals exchange genetic material with each other. Most of the time DNA is not exchanged, instead plasmid which is a small part of DNA found in cytoplasm is exchanged. In that way organisms can gain new traits from the other organism.

2. PARTHENOGENESIS It is the formation of a new organism from the unfertilized egg. Male bee (n)Queen bee(2n) Mitosis Meiosis Mitosis Meiosis Sperm(n) Egg(n) parthenogenesis parthenogenesis Female bee(2n) Male bee(n) Queen bee(2n) Worker bee(2n)

3. HERMAPHRODITISM Some organisms can carry both male and female reproductive system and organs. This process is called hermaphroditism. Earth worms, most of the plants are hermaphrodites. Some organisms can carry both male and female reproductive system and organs. This process is called hermaphroditism. Earth worms, most of the plants are hermaphrodites.

3. HERMAPHRODITISM Some organisms can carry both male and female reproductive system and organs. This process is called hermaphroditism. Earth worms, most of the plants are hermaphrodites. Some organisms can carry both male and female reproductive system and organs. This process is called hermaphroditism. Earth worms, most of the plants are hermaphrodites. Hermaphroditism causes variation but it is not as much as the variation in sexual reproduction. If same individual uses sperms and eggs from itself it will cause little variation. If gametes from 2 separate individuals fertilize they will cause more variation.

Metagenesis In some organisms sexual reproduction follows asexual reproduction. This is metagenesis. In some organisms sexual reproduction follows asexual reproduction. This is metagenesis. Moss Moss Plazmodium Plazmodium (asexual in human, sexual in mosquito) Fern Fern n n2n

Plasmodium n n n (Mayoz)

1. a female Anofele takes in gametes from the blood of human. 1. a female Anofele takes in gametes from the blood of human. 2. gametes are fertilized inside the mosquito’s intestine. Zygote forms. 2. gametes are fertilized inside the mosquito’s intestine. Zygote forms. 3. Zygote forms spores by meiosis in mosquito. 3. Zygote forms spores by meiosis in mosquito. 4. Mosquito bites human and infects him with spores. 4. Mosquito bites human and infects him with spores. 5. Spores reproduce asexually in blood and liver of human. And spores form gametes. 5. Spores reproduce asexually in blood and liver of human. And spores form gametes.