Reproductive Animal Strategies

Question 1

What is the goal of each species?

Answer 1

REPRODUCTIVE EFFORT : produce the maximum number of surviving offspring while using the least amount of energy

Question 2

Courtship

Answer 2

• behavior designed to attract another animal for mating and breeding
  Simple
• chemical
• visual
• auditory stimuli
  Complex
• males who are larger, more elaborate physical features & display more courtship energy
  MAXIMISE REPRODUCTION
• ensures males & females find suitable mates
• times sexual behavior
• energy expenditure by male

Question 3

External fertilization

Answer 3

Takes place in water & occurs in most aquatic vertebrates
Not ideal - wasteful and uncertain
MAXIMIZE REPRODUCTION
- huge numbers of eggs and sperm
- swim side-by-side = ensures gametes are close together

Question 4

Internal fertilization

Answer 4

• occurs in terrestrial vertebrates
• male gamete released into female body
• birds & reptiles - cloaca (single opening in lower abdomen)
• mammals - penis
  MAX REPRODUCTION
• more certain

Question 5

Ovipary, ovovivipary & vivipary

Answer 5

The moment at which future offspring separates from a parent

- strategies indicate where embryo develops & how it’s nourished

Question 6

Ovipary

Answer 6

• eggs develop outside parent
• externally or internally fertilized
• egg yolk is their only food
  MAX REPRODUCTION (water)
• eggs released into water - enormous amount released = ensures survival of species
  MAX REPRODUCTION (land)
• few eggs produced = saves energy
• she’ll protects embryo

Question 7

Ovovivipary

Answer 7

• eggs fertilized internally
• kept inside body until they hatch = born live
  MAX REPRODUCTION
• fewer eggs produced
• developing embryo - less vulnerable
• young born fully developed- own food & escape predators

Question 8

Vivipary

Answer 8

• internal fertilization
• eggs do not have a shell - egg forms an embryo & the a foetus
• nourishment from mom through placenta
  MAX REPRODUCTION
• low energy expenditure for:
  = nourish & protect embryo & foetus
  = provide parental care after young are born

Question 9

Amniotic egg

Answer 9

Early vertebrates : eggs in water - no shell - live near water
Later vertebrates : eggs in terrestrial environment/ retained in body
MAX REPRODUCTION
- fluid-filled amnion surrounds & protects embryo
- yolk sac = nutritious food for embryos development
- chorion = allows gaseous exchange & forms placenta

Question 10

Precocial development

Answer 10

• hatch/born when almost fully developed
• energy expenditure in pre-natal development = less involved after birth
• once born : open eyes, hair/fur, large brains, immediately active/mobile
  MAX REPRODUCTION
• feed themselves
• hide from predators

Question 11

Altricial Development

Answer 11

• born/hatch not well developed
• parental energy - post-natal development
• once born - naked, cannot walk/fly, closed eyes, rely on parents
  MAX REPRODUCTION
• less energy pre-natal development = more for post
• reach reproductive age early
• safer from predation

Question 12

K-strategy

Answer 12

• few offspring
• high level of parental care
• climax species (produce more offspring than environment can hold)

Question 13

R-strategy

Answer 13

• numerous eggs

- no parental care = few eggs/offspring survive