Summary
Summary Reproductive strategies
- Course
- Life Sciences
- Institution
- 12th Grade
Complete summary and notes needed for matrics on the reproductive strategies. Applies to both IEB and NSC
[Show more]
Seller
Follow
Content preview
- These strategies produce the maximum no. of surviving offspring whileusing the least amount of energy / reproductive effort.
2. OVIPARY, OVOVIVIPARY, VIVIPARY:
- STRATEGIES: - these strategies show how embryo develops & how the embryo & foetus
1. External fertilisation vs. internal fertilisation
are nourished
2. Ovipary, ovovivipary, vivipary
3. Amniotic egg
4. Precocial & altricial development
5. Parental care > eggs develop outside parent (externally / internally fertilised)
> only nourishment for the developing foetus = egg yolk
1. EXTERNAL VS INTERNAL FERTILISATION: > How Ovipary maximises reproduction in aquatic environments:
- Lots of eggs are produced as they are vulnerable to predation
- External: occurs in water in most aquatic vertebrates (fish, frogs) - Fertilised eggs hatch into self-sufficient larvae
: very wasteful (large no. of eggs are produced = ↑ energy) - Larvae are dispersed (lessens competition with parents for food)
: fertilisation is not certain > How Ovipary maximises reproduction in land environments:
: Maximises reproduction → large no. of eggs released = ↑ - Few eggs are produced ∴ more energy goes into making sure eggs
probability of fertilisation have more yolk, that they are protected & incubated & cared for
- Internal: occurs in terrestrial vertebrates (reptiles, birds, mammals) (higher parental care).
: sperm is released directly into female’s body. - Eggshell protects the developing embryo from predators,
: most birds & reptiles mate using a cloaca (male & female), pathogens & physical damage & desiccation.
but male mammals use a penis.
: maximises reproduction → fertilisation is more certain as
gametes are placed close together, fewer eggs = less energy,
some eggs have a protective shell & eggs develop INSIDE > Eggs remain inside the female until they hatch, they are born “live”.
female (∴ protected) > How Ovovivipary maximises reproduction:
- Fewer eggs are produced ∴ more energy can be used to produce
large amounts of yolk → young are born fully developed
- Retained eggs & developing embryos are protected from
predation.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller moeadam. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R80,00. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
79976 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now