2.4 Reproductive Strategies Flashcards
What are the two types of reproduction?
Sexual and asexual
What offspring does asexual reproduction produce?
Genetically identicle to each other and the parent
What offspring does sexual reproduction produce?
Genetically different from each other and the parent(s), variation
What does genetic variability allow?
It allows species to adapt to environmental change
What are the advantages of sexual reproduction?
Genetic variation allows species to adapt to changing environments
Development of a resistant stage - eg seeds - Remain as a seed during winder bc of the bad conditions and start growing in spring!
What are the disadvantages of sexual reproduction?
Slower than asexual
Because of variation, not every organism produced will be capable of survival
What are the advantages of asexual reproduction?
Quicker than sexual
- rapid population growth when conditions are favourable
- out-compete other species!
What are the disadvantages of asexual reproduction?
Lack of genetic variation
- If the environment changes, the organism is less likely to adapt to it
How are haploid and diploid cells produced?
Haploids (eg gametes) - meiosis
Diploids - mitosis
Which sex produces the larger gamete?
Females
What is fertilisation?
The fusion of the haploid sperm and haploid egg to produce a diploid zygote.
How do most aquatic organisms reproduce?
Externally
How do most terrestrial organisms reproduce?
Internally
What is internal fertilisation?
Inside the female’s body
Intromitent organ used to put sperm inside the female’s body
Sminal fluid allows sperm to be motile and prevents dehydtration
Greater chance of fertilisation
Less gametes required
What is external development?
Fertilised egg or zygote undergoes development outside the female’s body.
Eg laying eggs
Larger egg = more development = less parental care
Aminiote egg - birds and reptiles. Shell, yolk emclosing the embryo, O2 diffuses in through the shell.
