Classification, Variation and Inheritance.

Question 1

Define classification.

1 mark

Answer 1

Classification is the process by which living organisms are grouped.

Question 2

List the five kingdoms of life and describe their characteristics.

10 marks

Answer 2

Animals (animalia) - Multicellular, heterotrophic feeders (no chlorophyll), no cell wall, complex cell structure with a nucleus

Plants (plantae) - Multicellular, autotrophic feeders (using chlorophyll), cell wall made of cellulose, complex cell structure with a nucleus

Fungi - Multicellular, saprophytic feeders (no chlorophyll), cell wall not made from cellulose, complex cell structure with a nucleus

Protists (protoctista) - Mostly unicellular (amoeba) with a few multicellular (seaweeds), complex cell structure with a nucleus

Bacteria (prokaryotae) - Unicellular, simple cell structure with no nucleus

Question 3

Distinguish between and give examples of vertebrates and invertebrates.

4 marks

Answer 3

Vertebrates have a backbone. Examples include mammals and reptiles.

Invertebrates do not have a backbone. Examples include insects and arachnids.

Question 4

Describe the properties of the phylum Arthropoda.

5 marks

Answer 4

• Exoskeleton
• Bilateral symmetry
• Jointed appendages
• Segmented bodies
• Specialised appendages

Question 5

Distinguish between insects and spiders.

4 marks

Answer 5

• Insects have 6 legs and spiders have 8 legs
• Insects have antennae and spiders have no antennae
• Insects have a head, thorax and abdomen and spiders have a cephalothorax and abdomen.
• Insects have 2 compound eyes and spiders have 8 simple eyes.

Question 6

List the properties of the five main groups of vertebrates.

10 marks (2 for each group)

Answer 6

Fish
* Fins
* Scales
* Gills
* Mainly cold-blooded; a few species are warm-blooded

Amphibians
* Soft, moist skin
* Can breathe through skin as well as lungs
* Live in both water and land
* Cold-blooded

Reptiles
* Scales
* Cold-blooded
* Lungs

Birds
* Feathers
* Wings
* Beaks
* Lungs
* Warm-blooded

Mammals
* Warm-blooded
* Hair
* Mammary glands
* Lungs

Question 7

Distinguish between cold-blooded and warm-blooded animals.

4 marks

Answer 7

Cold-blooded cannot regulate their internal body temperature. They cannot survive in extreme temperature conditions.

Warm-blooded animals can regulate and maintain constant internal body temperature. They can survive in any temperature range as they can adapt to it easily.

Question 8

Define variation and describe common variations between individuals.

5 marks

Answer 8

Variation refers to the differences that exist between individuals of a species.

Common variations include:
* Eye colour
* Blood group
* Hair colour
* Right or left-handedness

Question 9

Distinguish between and give examples of continuous and discontinuous variation.

4 marks

Answer 9

Continuous variation could be any value, e.g. height.

Discontinuous variation has distinct categores, e.g. blood type.

Question 10

Genes are inherited from 1)………. and they control 2)………. or 3)………. in individuals, e.g. hair colour.

3 marks

Answer 10

1) parents
2) traits
3) characteristics