Levels of organisation

What are eukaryotic cells?

Complex - include all animals and plant cells

What are prokaryotic cells?

Prokaryotic cells are smaller and simpler e.g. bacteria

What are organelles?

Tiny structures within cells, you can only see them using a powerful microscope

What are the organelles found in a typical animal cell?

• nuclear

• Cell membrane

• Cytoplasm

• Mitochondria

• Ribosomes

What is a nucleus?

An organelle which contains the genetic material that controls the cell’s activities. It is surrounded by its own membrane.

What is a cell membrane?

This membrane forms the outer surface of the cell and controls the substances that go in and out

What is the cytoplasm?

A gel-like substance where most of the cell’s chemical reactions happen. It contains enzymes which control these reactions

What are the mitochondria?

Small organelles where most of the reactions for aerobic respiration take place. Respiration transfers energy that the cell needs to work.

What are ribosomes?

Small organelles where proteins are made in the cell

Label a diagram of the animal cell

What do plants cells contain?

• chloroplasts

• Cell wall

• Vacuole

• Nuclear

• Cell membrane

• Cytoplasm

• Mitochondria

• Ribosomes

What do chloroplasts do?

Photosynthesis, which makes food for the plant happens here. Chloroplasts contain a green substance called chlorophyll, which is used in photosynthesis

What does the cell wall do?

A rigid structure made of cellulose which surrounds the cell membrane. It supports the cell and strengthens it

Label a diagram of the plant cell

What are similar cells organised into?

Tissues

What is a tissue?

A tissue is a group of similar cells that work together to carry out a particular function

For example, plants have xylem tissue (for transporting water and mineral salts) and phloem tissue (for transporting sucrose and amino acids). Or muscle tissue in humans

A tissue can contain more than one cell type

What are tissues organised into?

Organs

What is an organ?

An organ is a group of different tissues that work together to perform a function.

Lungs in mammals and leaves on plants are two examples of organs - they’re both made up of several different tissue types

What do organs make up?

Organ systems

What are organ systems?

Organs work together to form organ systems. Each system does a different job

For example, in mammals the digestive system is made up of organs including the stomach, intestines, pancreas and liver