B1 Characteristics of living organisms

Movement

A living organism must be able to move all of, or part of its body.e.g.Pants move leave in response to a stimulus (such as light), structures in a cytoplasm of living cells move.

Respiration

Chemical reactions in cells that break down nutrients and release energy. The energy released is used for the chemical reactions that keep the living body alive. Together the reactions are called a metabolism.

Sensitivity

Living organisms can detect (sense) and respond to changes in their surround environment.

For example us humans can see hear and respond to touch. Organisms can also detect and respond to changes within their bodies (the internal environment)

Growth

The permanent increase in the size of an organism. Can also be defined as the increase in dry mass (non water mass) of cells or the whole organism.

This is because the total mass of an organism varies depending on how much the organism consumes. Dry mass only measures the amount a body increases in size when nutrients are absorbed into cells and increase the number and size of cells.

Reproduction

The organism making more individuals of its type of organism.This includes making gametes (sex cells) and fertilising those gametes.

Excretion

The removal of any toxic (poisonous) substances that may damage the living cells in the body. These are produced during metabolic reactions taking place within the body. Some are waste products that the body cannot use (such as carbon dioxide during respiration). These can be toxic so must be removed by excretion. Sometimes a substance may be in excess so must also be removed.

Nutrition

This is the process is which the body takes in nutirents(raw materials needed by the cells to release energy and make more cells for growth, development or repair.

In plants this is Light, Carbon dioxide, water and mineral ions like nitrate and magnesium.

In animals these are organic compounds like carbohydrates and proteins, mineral ions like iron and calcium, and usually water.

Excess

When something is at an amount where there is more than what is needed.

Cytoplasm

The Jelly like liquid inside a cell that contains the cell structures and is where the chemical reactions take place.

Metabolism

The reactions that occur inside the body that keep an organism alive.

Plant

A multi-celled organism that gets its nutrition from photosynthesis. Made of cells that contain a nucleus and cell wall.