Reproduction Flashcards
What is the ideal of Eproduction?
Unlimited resources to support maximal growth, long life, and continuous production of offspring. However most organisms do not live in these conditions; energy must be spent to find food, avoid predators, etc…
What is the ultimate goal of managing an energy budget?
Have energy left over to allocate to reproduction. Natural selection has resulted in numerous strategies called life history traits to maximize fitness
What is the life history theory?
Success in the past shapes the life history traits of a species
What affects life history traits?
The environment does by influencing energy budgets (amount of light, food sources, shelter, etc…).
What does maximizing reproductive success involve?
Trade-offs due to fixed energy budgets and selective pressures (the environment)
Where do trade-offs arise from?
Limits in energy budgets. Its impossible to maximize both traits simultaneously, any gains in one trait will result in the loss by the other
What is indeterminate growth?
Growth of organism continues throughout the lifespan (ectotherms)
What is determinate growth?
Growth of organism ceases what adult state is reached (endotherms)
What is asexual reproduction?
Produces clones (exact copies)
- Prokaryotes replicate their genome and then divide by binary fission
- Some eukaryotes replicate their genomes and divide by mitosis
What is sexual reproduction?
Produces recombinants (combined genomes)
- Replicated genomes are halved into gametes and combined with other gametes to produce a zygote
- Only in eukaryotes
What are the life history traits?
- Growth rate
- Parental investment
- Number of offspring (fecundity)
- Frequency of reproduction (parity)
- Size/age of sexual maturity
- Size of offspring
- Longevity/life expectancy (mortality)
What is passive care?
Pre-birth energy investment (seed development, gestation, etc…)
What is active care?
Post-birth energy investment (raising offspring)
What is semelparity?
individuals of the same species can breed only once in its lifetime (breed and die)
What is iteroparity?
Individuals of the same species can breed more than once in its lifetime
