IGCSE Biology Notes

Grade 10 Biology Revision Guide

Characteristics of Living Organisms
Nutrition:
Respiration:
Excretion:
Sensitivity:
Movement:
Homeostasis:
Reproduction:
Growth:

Taking in food for growth and releasing energy.
Burning glucose to release energy.
Removing waste material like urea formed during chemical reactions.
Responding to changes in the environment.
Transport inside cells and moving the body.
Control their internal conditions.
Increasing the number of organisms.
Increasing the number of cells.

Variety of Living Organisms
Plants:
o o o o o o Multicellular organisms
Contain chloroplasts and are able to carry out photosynthesis
Have cellulose walls outside the cell walls to provide support to the cell
Store carbohydrates as starch and sucrose
Have large permanent vacuoles filled with cell sap that contains water and dissolved substances
Vary greatly in size and shape
 Example of flowering plant:
Rose
 Examples of cereals:
Maize
 Examples of non-flowering plant:
Conifers
Animals: o Multicellular organisms o Do not contain chloroplasts and cannot carry out photosynthesis o Do not have cell walls o Have small temporary vacuoles o Usually have a nervous system and can move from one place to another o Often store carbohydrates as glycogen
 Example of a vertebrate is human
 Example of invertebrate is earthworm
Fungi:
o Cannot carry out photosynthesis o Some are multicellular:
 Consist of mycelium made from thread-like structures called hyphae, which contain many nuclei
 Reproduce by spores
Example:
Mucor o Some are single celled:

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Grade 10 Biology Revision Guide
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Have cell walls made of chitin
Reproduce by budding
Example:
Yeast o Feed by extracellular secretion of digestive enzymes onto the food material and absorption of the organic products. Also known as saprotrophic nutrition. o Store carbohydrates as glycogen.
Bacteria:
o Microscopic single-celled organisms. o Lacks a nucleus but contains a circular chromosome of DNA o They have cell