100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary IB Biology Unit 4- Ecology CA$10.48   Add to cart

Summary

Summary IB Biology Unit 4- Ecology

 63 views  0 purchase
  • Course
  • Institution
  • Book

Summary Notes designed for the International Baccalaureate Diploma Programme. These notes are detailed yet concise, with all the information to achieve a 7 in IB Biology HL or SL. These notes were made using information from the IB syllabus, Oxford IB Diploma HL Biology Textbook, Bioninja and the B...

[Show more]

Preview 1 out of 3  pages

  • No
  • Unit 4- ecology
  • May 2, 2020
  • 3
  • 2019/2020
  • Summary
avatar-seller
Unit 4.1
• A species is a group of organisms which can breed together and produce fertile, viable
offspring.
• A population is a group of organisms of the same species that are living in the same area and
the same time.
• A community is a group of populations living and interacting together in a given area.
• A habitat is the environment where a species normally lives.
• A community forms an ecosystem by its interaction with the abiotic environment.

• Living organisms obtain chemical energy in two ways:
• Autotrophs (producers) synthesise organic molecules by using energy obtained from:
• The sun during photosynthesis.
• The oxidation of inorganic molecules (chemosynthesis).
• Heterotrophs (consumers) obtain organic molecules from other organisms by:
• ingesting them from living or recently killed organisms (consumers)
• ingesting them from non-living organisms (detritivores)
• secreting digestive enzymes and then absorbing the products (saprotrophs)
• Mixotrophs can act as both consumers and producers

• The supply of inorganic nutrients to the earth is limited, so nutrients are recycled.

• Ecosystems are mostly self-contained and are self-sustainable for long periods of time as they
are able to gain energy and recycle nutrients and wastes.

• Mesocosms are enclosed environments that allow a small part of a natural environment to be
observed under controlled conditions. Steps to make one include:
• A bottom layer pebbles to act as drainage followed by a layer of
activated charcoal to prevent mould.
• A layer of sphagnum moss for separation and then soil on top.
• The terrarium used must be clear and able to be fully sealed.

• Species can show a positive or negative association based on
whether they are found in the same habitat or not.
• The presence of two species can be obtain using quadrat
sampling, where a quadrat (rectangular frame) is placed on the
ground and the types of species in the quadrat is recorded.
• A chi-squared test uses this data to determine if there is a
statistically significant association between the distribution of two species.




Unit 4.2
• Photosynthesis converts light energy into chemical energy.
• Chemical energy in carbon compounds flows through food chains by means of feeding.
• The position an organism occupies within a feeding sequence is known as a trophic level.
• Producers always occupy the first trophic level.
• Organisms in a food web can be part of more than 1 trophic level.

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

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

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

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 these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller tiyadevinamistry. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for CA$10.48. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

77764 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
CA$10.48
  • (0)
  Add to cart