definitions Flashcards
Isogamy
= gametes are similar size
Simultaneous Hermaphroditism =
male and female reproductive organs at the same time eg earthworm
protandrous:
switch from male to female
protogynous:
switch from female to male
Low assimilation efficiency
= efficiency by which animals convert the food they ingest into energy for growth and reproduction
Syncytial layer –
all cells fused, no cell boundaries (= neodermis)
Oviparity =
eggs laid and develop outside the mothers body
ovo-viviparity (aplacental viviparity) =
eggs retained within mother, no placenta, young born
viviparity (placental viviparity) =
retained within mother, placental transfer of nutrients, young born
Iteroparity =
Where organisms produce offspring in a series of separate events during and after which the organisms maintain themselves in a condition that favours survival to subsequently reproduce again (slow and steady)
Semelparity =
= Where organisms produce all their offspring in a single reproductive event over one relatively short period (fast and furious)
r-selected =
production of a large number of offspring (of whom only a minority may survive) as early in life as possible, live fast, die young
K-selected
= production of a smaller number of ‘fitter’ offspring with higher chances of survival
Desiccation =
extreme dryness
Endodermic
= internal generation of heat
Ectodermic =
external generation of heat
Diffusion
= movement of solutes
Osmosis =
movement of water
‘Osmolarity’ =
is the sum of osmotically active particles in solution
Osmoregulation =
is the controlled movement of solutes between internal fluid & environment
agametic:
• no gametes (eggs and sperm) • fission • budding • Fragmentation that forms a new organism without fusion with another gamete
parthenogenetic:
- development of unfertilised eggs
- offspring from a single cell (virgin birth)
- apomixis (eggs from mitosis)
- automixis (eggs from meiosis)
fission =
separation of a parent into two or more individual
Budding =
new individuals arise from outgrowths in existing ones
Fragmentation =
= parent’s body broken into several irregular pieces, with some or all regenerating into complete adults
Parthenogenesis =
means development of an embryo from an unfertilized egg cell