Flashcards in Chapter 5.2 Deck (15):
What is asexual reproduction?
When only one parent is needed to produce offspring. Offspring will carry the identical genetic information as the parent (clones)
Identify 5 methods of asexual reproduction.
1. binary fission
4. vegetative reproduction
5. spore formation
What happens in binary fission? Give examples.
A single parent cell replicates and divides into 2 equal parts (replicates genetic info) and binary fission only occurs in unicellular organisms
ex: amoebas streptococcus
ex: alexandrium acatenella (marine algae)
What happens in budding? Give examples.
Budding occurs in multicellular organisms. Area of an individual may undergo repeated mitosis and cell division and can develop into an indentical organism.
Bud can detach from parent to become an individual or stay attached to their parent.
What happens in fragmentation? Give examples.
When an organism breaks apart and each fragment can develop into a clone of its parent
ex: sea star/starfish
ex: burasian milfoil (a plant)
What happens in vegetative reproduction? Give examples.
It occurs in plants. When special cells usually in stems and roots, divide repeatedly to form structures that develop into a plant identical to its parent.
ex: tulips and daffodils
ex: strawberry runners
ex: potato sprouts
What happens in spore formation? Give examples.
Forms single celled spores. Reproductive cells that grow into new individuals by mitosis. Relies on water and wind to carry spores.
ex: mosses and ferns
ex: fungi (bread mold)
What are the advantages of asexual reproduction?
Large numbers of offspring can be reproduced quickly.
Large colonies can form and out-complete other organisms.
Better chance of species surviving when living conditions or predators charge.
Energy not required to find a mate.
What are the disadvantages of asexual reproduction?
A negative mutation in the parent will be copied into offspring.
Sometimes can produce offspring too close together, so they compete for food and space.
Unfavorable conditions (extreme temperature) can wipe out entire colonies.
What is reproductive cloning?
To produce a genetic duplicate of an existing or previously existing organism with desirable qualities.
What is the process for reproductive cloning?
1. Transfer the nucleus of a body cell into an egg without a nucleus
2. A gland cell is removed from the organism. This cell and the egg are placed next to each other in a bath of chemicals
3. A jolt of electricity causes the two cells to fuse
4. The fused cell begins to dividing to form an embryo
5. Fused cell is transplanted into a surrogate (substitute) mother
What is therapeutic cloning?
Cloning that is used to correct health problems. Human embryonic and adult stem cells can be used
Why do scientists prefer embryonic stem cells over adult ones?
Embryonic cells can become any of our 200 body cells.
Adult cells are not as adaptable as embryonic stem cells.
What are stem cells
Cells that have potential to become many different cells