1a: Characteristics of living organisms

Question 1

Explain nutrition

Answer 1

The taking in of nutrients, such as organic substances and mineral ions, into the body. Nutrients are the raw materials that cells need to release energy, carry out chemical processes and make more cells.

Question 2

Explain respiration

Answer 2

A series of reactions that take place in living cells to release energy from nutrients. This energy is used for all of the chemical reactions that keep the cell alive.

Question 3

Explain excretion

Answer 3

Living cells produce many products from the reactions that take place inside them. Some of these are waste products - materials that the body does not use. For example, animals cannot use carbon dioxide produced during respiration. Waste products may also be toxic, so they must be removed from the body by excretion.

Question 4

Explain sensitivity

Answer 4

Living organisms are able to detect and respond to changes in their external and internal conditions.

Question 5

Explain movement

Answer 5

In all living cells, structures in the cytoplasm move. In more complex organisms, the whole structure may move. Animals may move their entire bodies; plants may move parts of their body in response to external stimuli such as light.

Question 6

Explain homeostasis

Answer 6

This is the control of internal conditions, to provide the best conditions inside the cells for all the reactions needed for life to exist. For example, when we eat and drink we take in water - our body controls how much water is absorbed and removed from the blood, so that cell processes can continue to work efficiently.

Question 7

Explain reproduction

Answer 7

This includes all processes that result in making more individuals of that kind of organism, such as making gametes and the fertilisation of gametes.

Question 8

Explain growth

Answer 8

This is the permanent increase in the size and/or dry mass(mass without water content) of cells or the whole body of an organism. Your mass changes throughout the day, depending on how much you eat and drink, but your growth is the amount by which your body increases in size when you take nutrients into cells to increase their number and size.

Question 9

What are the eight life characteristics

Answer 9

Movement
Respiration
Sensitivity
Homeostasis
Growth
Reproduction
Excretion
Nutrition