Key Area 4-Sex and Behaviour Flashcards
Describe egg production
Few we produced
Large energy store is required
Expensive to produce
Describe sperm production
Many are produced
No energy store required
Cheap to produce
What gamete requires the most parental care?
Egg cell
Describe how the problems with sex in sessile organisms are overcome
Barnacles have a long penis that extends and swaps speed with the next barnacle
Coral has eggs and sperm released simultaneously in the water
Flowering plants reproduce with pollination where gametes are transferred from another to stigma of another
What is internal fertilisation?
When there is no water in surrounding environment for the transfer of gametes
What is external fertilisation?
When there is water in the surrounding environment for the transfer of gametes
What are the benefits of internal fertilisation?
- fewer egg cells are produced
- high rate of reproductive success
- low mortality rate of offspring
What are the costs of internal fertilisation?
- more energy invested per egg produced
- lots of energy invested in parental care
- protection for developing embryo must be given
What are the benefits of external fertilisation?
- little energy invested in parental care
- good survival numbers due to sheer number of gametes produced
What are the costs of external fertilisation?
- energy must be used to produce lots of gametes
- high mortality rate of gametes
- timing is difficult
What is parental investment?
The energy given to the production of gametes and care of offspring
How does parental care affect the offspring?
Parental investment increases the probability of production and survival of young
How does the environmental conditions affect the offspring?
If the organism lives in a stable environment they will have few, expensive Young where energy investment is high.
If environment is unstable then many young are produced that get low energy investment and receive very little parental care.
What are the two categories of parental care?
R-selected and K-selected
Describe R-selected classification?
Young have relied development
Adults are of a small size
Many and small offspring
Short generation time
Describe K-selected classification?
Young have slow development
Adult are of a large size
Few and large offspring
Long generation time
What is the name given to the number of offspring?
Clutch size
What are the limitations of using r and k selected classification?
Some organisms are difficult to place into one of these distinct groups and simplistic classification of parental investment into the two groups does not reflect continuous range of life history strategies
What is optimal reproduction?
Based on the premise of a trade off in terms of the number and quality of current offspring versus potential further offspring
What is polygamy?
Promiscuous and short lived interactions
What is monogamy?
One partner and long term interactions
Which reproductive strategies is more likely with more parental care?
Monogamous
How is paternity a factor in choosing reproductive strategy?
With internal fertilisation the female is guaranteed to be the parent but preening is not guaranteed, so promiscuity or polygamy is more likely to ensure genes are passed on
What is sexual dimorphism?
When makes and females look distinctly different
