Asexual/sexual reproduction Flashcards
(39 cards)
Genetic Diveristy
the amount of genetic variation that exists between individauls
Gene pool
The sum of differnet alleles present in a certain population
note in a gene pool”
the number of dominant alleles is 10/16
the number of recessive alleles is 6/16
What does it mean to have a larger gene pool/what is the advantage of this
Larger genetic diveristy
for exmaple, the population of cheetahs decreased during the ice age as tehey had a small gene pool so the cheetahs were forced to reporudce with thei relaitvives, this results in diseaes alleles being passed onto offpsirng ulitmaltey decreasing populatiom.
Importance of genetic diveirtiaisty
Ensures survival of species against changes to the environment and allows evoultion to be contious
What optimises the individulls chance of survivng to new change
having a larger gene pool
Natural selection
when factors such as the enviornmrent act of a population causing change to genetic diveristy
Sexual reproduction
the fusion of 2 gametes through fertilsiation
In sexual reproduction, how does genetic varation occur
genetic varation occurs due to the meiosis of gametes in sexual reproduction
What are reproductive strategies
adaptions to reproduce that improve the sucess of the sutvival of a specfies
examples of organisms that use reproductive strategies and how explain!
Male statin bowers- have a glossy blue-blakc plumage and build a decorative bower to attract females—they use their bower as a courtship arena
Brown male Antechnius-They live only 11 months and die from stress and exhausation following a 2 week breeding
Angiosperms(flowering plants)- Offer nectar, scents, colours and petals to attract pollinators to deliever pollen to the stigma of the flower to allow fertilsation and seeds production
what is internal fertilsiatoion
internal fertilsiation is where fertilisation occurs inside the body–this allows the young to be protected from predators
types of internal fertilisation(sexual reproduction)
- oviparity
- ovoviviparity
- viviparty
oviparity
the fertiilsed eggs are laid outside the bodt and the egg recievevs nourishment form the yolk eg. fish and birds
Ovoviviparity
The fertilised eggs are retained from the female and the embyro recieves nourishmetn from the yolk–when they hatch the young ones are fully developed
eg. lizards or snakes
Viviparty
the young develops inside the mother and recives nourishmenet throuhg the placneta
eg. most mmammels and cartilagonious fihs
evolution
a process that results in changes to genetic materila of a population over time
what is external fertilisation strategies
fertilsiaton occurs outside the body usually in water when the female releases an egg and the male releaes sperm into the same envornmrent causing fusion by chance.
it occurs in fish frogs and starfish
How are some gametees lost or destroyed
some gametes or lost or destroyed through predation
Advantages VS disadvantages of sexual reproduction
Advantages:
1.increases genetic diveristy of a population
2. greater chance of surviving new selection pressures such as disease
3. reduced chance of genetic disorders passed onto offspring
Disadvantages:
1. Time and energy to attract and find a mate
2. Tranferable disease due to sexual intercourse
3. Ineffiecnet due to many gametes not fertilsaied
Asexual reproduction
a single parent produces offpsring idenitcal to themsleves without the fusion of gametes
occursin both unicelluar and multicelluar orgnaims eg. fungi plants and bacteria
What are the 6 reproductive methods in asexual reproduction
- Binary fission
- Budding
- Fragmentation
- Vegegative propagation
- sporogenisis
- parthenongensis
What is binary fission
A fast process that occurs in prokaytoes like bacteria where one parent cell divides into 2 identical daughte rcells and the cell duplicates and elongates
Compare binary fission to mitosis
no spindle fibres or breaking down of nuclear memebrane in binary fission and mitosis takes a couple of daystheprocess whereas binary fission only takes a couple of minutes
Budding
A new smaller individual is produced from the outgrowth of the parent organism
occurs in hydra and yeast–note that the new orgnaism produced is smaller from the origninal one