1 thing has to happen
MITOSIS
Mitosis
The process of making new cells that are identical to the parent cells - this process occurs in all living things, to replace old/dead/damaged cells, and also to make new cells to grow things bigger!
- Asexual reproduction produces identical offspring - clones - no variation between individuals involved!
- You may also hear it be referred to as vegetative reproduction.
- Only one parent is involved. It does not involve gametes, therefore no meiosis, pollination, fertilization or seeds are made/occur. Offspring are genetically identical to the parent plant and can be produced very quickly compared to sexual reproduction! Mitosis is the process involved (not meiosis) and often offspring grow close to the parent plant.
There are 5 methods of asexual reproduction
+ 1 that is facilitated by humans (cuttings).
+ 1 that is facilitated by humans (cuttings).
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Tubers
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Rhizomes
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Runners
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Bulbs
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Corms
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Cuttings
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Rhizomes - e.g. ginger
Rhizomes are stems that grow below the ground (just below soil level). They send out roots and shoots from 'nodes', which develop into a plant that can then produce more rhizomes. Parent and offspring plants stay connected through the underground stem system.
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Runners - e.g. strawberries
Runners have their stems above the ground and they grow across the top of the ground. At each 'node' roots begin to grow downwards and shoots grow upwards, forming a new plant that is still attached to the parent plant. Eventually they detach (when offspring can sustain self).
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Cuttings
It is easy to grow a new plant from a cut-off part of a plant someone else has, or that you have (and want more of). First you need to cut a bit of stem off and remove all the excess leaves (or put a plastic bag over them all) - this is to reduce any water loss through the leaves (transpiration). The stem then needs to be placed in soil or water from which roots will grow and form the base of the stem. Ensuring adequate nutrients and water are available will assist the 'cutting' to grow into a plant that is genetically identical to the one you cut it off of! Here's some more info if you're interested in trying it!
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Advantages vs. disadvantages
Advantages of...
Sexual reproduction in plants |
Asexual reproduction in plants |
Genetic input from two parents creates unique offspring and within a population this creates variation - variation is very important as if there was to be a change in the environment the population is likely to be able to withstand that change. |
The fact that this method does not require flowers, the production of gametes, pollination, fertilization and seed dispersal means that it is a lot faster! Energy that would be spend making flowers and seeds is put into making lots of offspring instead. |
Less competition between parent and offspring plants, as seed dispersal ensures seeds are washed/blown/delivered away from the parent plant. |
If a plant is able to reproduce in its environment, its environment must have desirable conditions for growth and reproduction. Therefore if a plant was to do asexual reproduction and its offspring be located very close by, they too would be in desirable conditions! |
Disadvantages of...
Sexual reproduction in plants |
Asexual reproduction in plants |
A lot of energy is put into creating flowers as well as pollen, seeds and fruit - this energy could be spend elsewhere! |
There is only genetic input from one parent and the offspring is guaranteed to be genetically identical to that parent (as they grow from them via mitosis) - this means the population has very little genetic variation - not good if a disease were to hit! |
Pollination and therefore fertilization is dependent on some sort of vector to facilitate the process. What if it's not windy? What if there are no animals around? All that energy making pollen and flowers might be for nothing! |
Offspring often grow right next to the parent plant (as offspring often grow directly from the parent plant) - this means there is more competition for resources between parent and offspring. |
Seeds are created but many will not land in conditions for germination (WOW), again more energy wasted. |
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Keep these bullet points in mind
Sexual reproduction
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Asexual reproduction
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