Biology Unit 2

HideShow resource information
  • Created by: Ssammy29
  • Created on: 26-04-16 18:11

Animal Cells

Features of an Animal Cell:

  • Nucleus = controls the cells activities
  • Cytoplasm = where chemical reactions take place
  • Cell Membrane = controls the movement of materials in and out of the cell
  • Mitochondria = where energy is released during aerobic respiration
  • Ribosomes = where protein synthesis takes place
1 of 9

Plant Cells

Features of Plant Cells

  • Plant cells contain everything in an animal cell

They also have:

  •  Cell wall = rigid and made of cellulose for support and structure
  • Chloroplasts = contain chlorophyll for photosynthesis. They absorb light energy to make food
  • Permanent Vacuole = containing cell sap
2 of 9


  • Much smaller than animal and plant cells - can only be seen with very powerful microscopes
  • Have a cell membrane and a cell wall which surround cytoplasm
  • Do not have a nucleus
  • Genetic material is in the cytoplasm
  • When they multiply they form a colony
3 of 9


  • A single-celled organism
  • Have a nucleus, cytoplasm and a membrane surrounded by a cell wall
4 of 9

Specialised Cells

As an organism matures, each cell develops into a particular type. The structure of a cell is linked to it's function:

  • Many mitochondria - needs a lot of energy e.g. muscle cell
  • Many ribosomes - is making a lot of protein e.g. gland cells which produce enzymes
  • Cells with tails - able to move e.g. sperm cells
  • Receptor cells - have special structures which enable them to detect stimuli e.g. cone cells in eye are light sensitive
  • Neurons - specialised to carry impulses from receptors to the CNS
  • Plant cells - many chloroplasts to carry out photosynthesis
  • Root hair cells - increase the surface area of the root to absorb water and mineral ions efficiently
5 of 9


  • Molecules in gases and liquids - move around randomly (because of the energy they have)


  • The spreading out of the particles of a gas, or of any substance in solution
  • The net movement into or out of cells depends on the concentration of the particles on each side of the cell membrane
  • Because the particles move randomly, there will be a net (overall) movement from an area of HIGH CONCENTRATION to an area of LOW CONCENTRATION
  • Difference in concentration between two areas = CONCENTRATION GRADIENT
  • Larger the difference in concentration = faster the rate of diffusion


  • Diffusion of oxygen into the cells of the body from the bloodstream (as the cells respire)
  • Diffusion of carbon dioxide into actively photosynthesising plant cells
  • Diffusion of simple sugars and amino acids from the gut through cell membranes
6 of 9


A tissue = a group of cells with similar structure and function.

Animal tissues include:

  • Muscle Tissue = can contract to bring about movement
  • Glandular Tissue = to produce substances such as enzymes or hormones
  • Epithelial Tissue = covers some parts of the body

Plant tissues include:

  • Epidermal Tissue = covers the plant
  • Mesophyll = can photosynthesise
  • Xylem and Phloem = transport substances around the plant
7 of 9


Organs are made of tissues.

The stomach organ is made of:

  • Muscular tissue = churn the stomach contents
  • Glandular tissue = produce digestive juices
  • Epithelial tissue = cover the inside an outside of the stomach

Leaf, Stem and Root are plant organs which contain epidermal tissue, mesophyll, xylem and phloem

  • Groups of organs from organ systems to perform a particualr function e.g. difestive system
8 of 9

The Digestive System

Food you eat - must be changed from insoluble molecules into soluble molecules.

Soluble molecules can be absorbed into the blood.

The Digestive System is responsible for this process:

Digestive System = a muscular tube which includes:

  • Glands - such as the pancreas and salivary glands (which produce digestive juices)
  • Stomach and small intestine - where digestion occurs
  • Liver - produces bile
  • Small intestineabsorption of of soluble food occurs
  • Large intestine - water is absorbed from the undigested food (producing poo)
9 of 9


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Cells, tissues and organs resources »