Topic 4 - Reproduction Flashcards
What is a hermaphrodite? Give an example.
An organism that possesses both male and female genitalia / produces both eggs and sperm.
Example - sea slug.
What is the difference between haploid and diploid?
Haploid cells contain one set of chromosomes, whereas diploid cells contain two sets of chromosomes.
What is a zygote?
A cell fused in sexual reproduction that contains two sets of chromosomes (one from each parent)
How does asexual reproduction differ from sexual reproduction?
Asexual reproduction is essentially cloning where a single-celled organisms replicates through mitosis.
In sexual reproduction, cells divide then recombine genetic information from both parents.
Name THREE forms of asexual reproduction and give a brief explanation of each.
B = Budding - a new one grows as an off-shoot
F = Fragmentation - splits into parts then each will regenerate/grow back into a whole
BF = Binary Fission - existing one splits into two or more equal parts
What is parthenogenesis?
A form of asexual reproduction where the egg develops without being fertilised.
Example - male drones of parasitic wasps.
Briefly explain the terms monogamy and polygamy.
Monogamy - male and female breed exclusively with one another.
Polygamy - the male and/or female has multiple partners.
What are the types of polygamous relationship?
Polygyny - one male and many females
Polyandry - one female and many males
Polygynandry - many females and many males
What is polygyny?
Name three different sub-sets of it.
Polygyny is where one male breeds with many females.
Three different types are:
- Resource defence
- Female defence (harems)
- Leks (display groups)
What is fecundity and how is it different from fitness?
Fecundity is the number of eggs produced.
Fitness is an overall measure of lifetime reproductive success and survival.
Briefly explain the concept of life history trade-off.
Resources (nutrients & energy) can only be allocated to one activity. Some are used for survival and growth, others for reproduction. If lots are needed for reproduction, life will be shorter, etc.
What are the two sides of the life history trade-off?
Somatic effort = survival and growth
Reproductive effort = reproduction
What are the two strategies in the life history dichotomy?
k-strategy - compete and survive as an adult
r-strategy - reproduce as much as possible
What are the two broad categories of anuran breeding system, and over what time-frame do they occur?
Explosive breeding - a few days or weeks
Prolonged breeding - six months or more
Give two examples of how male mating calls convey information to others.
Females discern best calls to indicate fitness = mating.
Males discern best calls to indicate strong competitions = conflict avoidance.
What FOUR parameters can be used to describe a frog call?
- Intensity (loudness)
- Pitch (frequency)
- Duration
- Repetition rate
What is the different in inter- and intra-sexual selection?
Inter-sexual selection selects based on traits that will attract the opposite sex, eg. display feathers in birds.
AKA Female Choice.
Intra-sexual selection acts on traits within the same gender, eg. horns for fighting other males. AKA Male Competition.
What is speciation?
A lineage splitting event that produces two or more separate species.
What is a species?
A group of organisms that interbreed in natural circumstances to produce fertile, viable young that themselves go on to breed. The group is reproductively isolated from other groups.
How does speciation occur?
Barriers are put in place such that parts of the population can no longer interbreed.
What are the two broad categories of reproductive barrier leading to speciation?
Pre-zygotic - occuring before mating
Post-zygotic - occur soon after mating
What is the difference between allopatric and sympatric speciation?
Allopatric - populations are geographically separated and diverge; unable to mate if later come together.
Sympatric - populations occupy same area but adapt and diverge so they no longer interbreed.
What is parapatric speciation?
Two populations are geographically close but non-overlapping. They diverge into two species, but a hybrid exists on the boundary where breeding still occcurs.
What is apoptosis?
It is a programme of cell death.
Occurs for example in caterpillar cells as butterfly cells grow and take over during metamorphosis.
What are the three stages of metamorphosis in frogs?
Pre-metamorphosis - grow in size
Pro-metamorphosis - legs form and growth continues
Metamorphic climax - full transformation; tail absorbed
