There is only one parent needed, reproduce rapidly to produce many new individuals +has a genetic make up so can produce them to a particular gene patten.
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what are the disadvantages of Asexual reproduction
They are genetically identical and so they cant adapt to quick change in enviroments
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What are the advantages of sexual reproduction?
Better adapted to the new conditions due to their different genetic make-up.
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What are the disadvantages of sexual reproduction?
requires two parents and can take longer
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what is the human life cycle?
Adult carries out mitosis for growth and repair- meosis in sex organs to produce gametes- meiosis produces cells in humans containing 23 chromosomes- egg and sperm fuse to form a zygote with 46 chromosomes in humans- repeated mitosis
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what is external fertilisation?
Aquatic organisms discharge their gametes into the sea- low chance of sperm meeting egg- howver sexual coupling increases the chance of gametes meeting(female lays eggs laid and male releases seminal fluid over them)
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What is internal fertilisation?
Fertilisation occurring in the body of the female- an intermittent organ is used to introduce sperm into the females body
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what are the advantages of internal fertilisation?
less gametes are wasted, greater chance of fertilisation and there is protection on the young
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what is the amniotic egg?
it is in reptiles and birds. The egg had a fluid filled cavity surrounded by the membrane outside which is the protective shell.
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what is the mammalian embryo?
in mammals the young in kept inside the womb. It is nourished by the mothers blood supply via placenta and protected by the amniotic sac. Amniotic fluid is inside the amniotic membrane
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What are the aspects of parental care?
1. provision of shelter 2. feeding 3. protection from predators 4. may include some aspect of training
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why do organisms that provide a high level of parental car often produce fewer offspring?
1. increase chance of offspring surviving 2. less competition between offspring 3. more time/energy used to to care for off spring
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what is uni sexual?
male + female sex organs are contained in different individuals
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what is a hermaphrodite?
male + female gametes are produced in the same individual
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what are the advantages and disadvantages of hermaphrodites?
advs- individual is capable of forming fertilised eggs disv- possibility of self fertilisation leading to inbreeding which reduced genetic variability
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what are the importance of insects to humans?
dependent on insects for pollination of plants especially those we use as crops -- many insects carry diseases like malaria -- humans spend billions on insecticides
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what is incomplete metamorphosis?
there is larval stages which can take several months during development. the exoskeleton limits the growth and must shed in order to reach full size. Straight after moulting there is rapid increase in size.
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what is complete metamorphosis?
Adults specialise for dispersal of eggs and reproduction-- egg-- larval/nymph stage grows and develops and is specialised for feeding-- exoskeleton of larva is shed several times during development to increase the size of the larva-- pupa formed
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why did flowering plants become so successful?
they have a rapid life cycle- food store in seeds enable seeds to survive for long periods of time- seeds are protected by outer resistance layer (testa)- water is not required in fertilisation- wind and animals can be used in fertilisation
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Other cards in this set
Card 2
Front
what are the disadvantages of Asexual reproduction
Back
They are genetically identical and so they cant adapt to quick change in enviroments
Card 3
Front
What are the advantages of sexual reproduction?
Back
Card 4
Front
What are the disadvantages of sexual reproduction?
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