Biology Cells

SCIENCE REVISION:

By Katherine May Dinh

Biology

B1 Ð'- The Principles of Biological Classification and the Diversity of Organisms

B2 Ð'- Cellular Organisation and Function

B3 Ð'- Support and Movement

B4 Ð'- Photosynthesis

[B01] THE PRINCIPLES OF BIOLOGICAL CLASSIFICATION AND THE DIVERSITY OF ORGANISMS

Living organisms can be identified when having the general characteristics :

MRS GREN

M ovement

R espiration

S ensitivity

G rowth

R eproduction

E xcretion

N utrition

The Bionomial Naming system is a system that can identify every living organism with a universal name consisting of two words. The firs word is the genus and the second word is the species e.g Panthera leo Ð'- lion, Loxodonta africana Ð'- elephant.

Animals are organisms that feed on other organisms and usually move around.

Characteristics Ð'-

Each type of animal in the Animal Kingdom can be identified through characteristics.

Vertebrates :

Fish Ð'- e.g shark, seahorse

- scaly covering

- live in water

- gills for breathing

- eggs laid in water

- cold blooded

- skeleton of cartilage or bone

Reptiles Ð'- e.g crocodile, snake

- dry, waterproof scaly skin

- generally live on land

- lungs for breathing

- most have four legs

- some can swim

- others have reduced legs and slide along the ground (snakes)

- eggs laid on land with soft shell

- cold blooded

Amphibians Ð'- e.g frog, newt

- moist leathery skin without scales

- tadpoles have gills for breathing

- adults live on land, have lungs for breathing

- can swim, walk or hop

- eggs laid in water

- cold blooded

Mammals Ð'- e.g lion, dog

- covered with hair

- young fed on milk produced by the mother's mammary glands

- live on land, water, and in the air

- walk, swim or fly

- lungs for breathing

- warm blooded

Birds Ð'- e.g eagle, vulture

- covering of feathers

- live on land and in the air

- lungs for breathing

- wings for flying and beak for feeding

- eggs are laid in nests and have a hard shell

- warm blooded

Invertebrates :

Arthropods Ð'- have segmented body with a hard exoskeleton and jointed limbs. And they are divided into four groups mainly based on the number of legs.

Crustaceans Ð'- e.g shrimp, lobster

- between 5 and 8 legs

- two pairs of antennae

- mainly live in water

Arachnids Ð'- e.g spider, scorpion

- 4 pairs of legs

- No antennae

- Mouthparts have pincers

- Live on land

Myriapods Ð'- e.g centipede, millipede

- lots of legs (over 8 pairs but can have as many as 750 pairs)

- one pair of antennae

- lots of segments

Insects Ð'- e.g grasshopper, cockroach

- three pairs of legs

- one pair of antennae

- body divided into 3 parts

- usually 2 pairs of wings

[B02] CELLULAR ORGANISATION AND FUNCTION

All living organisms are made up of cells, which are the smallest units of living matter. There are animals cells and plant cells and they all share basic features of organisation that allow them to carry out their functions.

ANIMAL CELL Ð'-

PLANT CELL Ð'-

Cells can divide to make more cells, so that animals and plants can grow, repair their tissues & reproduce. (mitosis)

Tissues Ð'-

A group of cells of the same sort and do the same particular job (specialized) make up a tissue.

Muscles are tissues that contain cells that have become specialized muscle cells. Muscles are a type of tissue that can tighten up and relax.

Organs Ð'-

Different tissues combine to make organs which have a