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ASEXUAL REPRODUCTION
CHARACTERISTICS: - Only 1 parent required - Offspring are genetically identical to the parent. Offspring are called CLONES.
ADVANTAGES: - Don’t waste energy looking for a mate - Large populations of offspring can be produced quickly and outcompete other organisms for space, food and water
DISADVANTAGES: - a change in the environment can wipe out an entire population because they’re all clones. - temperature or climate change - disease - new predator - etc
TYPESA. BINARY FISSION - The parent splits into 2 equal halves. EXAMPLES
1. Mitosis2. Bacteria
3. Sea anenomes
3. Sea anenomes
3. Sea anenomes
4. Corals
B. BUDDING - offspring begins as a bud on the parent - the bud developes into an adult
- when old enough to survive on its own, it breaks away from the parent. Example: Hydra
C. FRAGMENTATION - a piece of the parent breaks off. - the parent will grow the piece back and the piece that broke off will grow into an adult Example: Starfish
Or planaria
D. SPORE FORMATION - Spores are specialized cells made by the parent - they have hard resistant shells that can withstand extreme conditions - spores are released into the air. - if they land in a suitable area, they break open and grow into a new adult.
Or Mould
E. VEGETATIVE REPRODUCTION - the way many plants reproduce - there are various ways plants do this example: -plants will send out special roots or stems called runners. - buds grow on the runner and will grow into new plants
Uses of vegetative reproduction:We can make crops grow fasterExamples:1. We can grow plants from existing plants instead of growing them from seed ie: potatoes can be grown by planting the buds on potatoes
2. Cuttings: take a part of the plant like a branch, put the end in nutrients and roots will grow. When big enough, it is planted.
3. Grafting: Attach a branch from 1 tree onto another. We can graft the branches from different types of apple trees onto 1 trunk, and the tree will grow different types of apples.
Reproductive Cloning: Making clones from the cells of an adult. - take a cell from the organism you want to clone and remove the nucleus. - take an egg cell from a female of the same species and remove its nucleus - put the first nucleus into the egg cell - put the egg cell back into the female and let it grow normally.
Therapeutic Cloning: used to grow new organsUse stem cells( unspecialized cells – they haven’t yet become any type of cell)- Take the nucleus out of a stem cell- Take the nucleus out of a cell from the organ to be cloned- Put this nucleus into the stem cell- Stimulate the cell to begin dividing and becoming a new organ- Transplant back into the patient