chapter 3 - diversity of living organisms

Question 1

State the structure of a virus.

Answer 1

• non-cellular
• core is a strand of genetic material (DNA/RNA)
• core is enclosed in a protein coat, called capsid
• capsid consists of capsomeres

Question 2

State the arguments that viruses are living organisms.

Answer 2

• viruses are capable of reproduction
• they have genetic material (DNA/RNA)

Question 3

State the arguments that viruses are not living organisms.

Answer 3

• viruses don;t have a cell structure
• 6 out of the 7 characteristics of living organisms do not apply to them
• they can only reproduce within the cells of the host organism.

Question 4

Name the 7 characteristics of living organisms.

Answer 4

• movement
• respiration
• excretion
• sensitivity
• growth
• reproduction
• nutrition

Question 5

What is movement?

Answer 5

an action by an organism or part of the organism causing a change in position or place.

Question 6

What is respiration?

Answer 6

Organisms are able to break down glucose and other substances inside their cells to release energy.

Question 7

What is sensitivity?

Answer 7

Organisms are able to detect stimuli in their environment and respond to it approprately.

Question 8

What is growth?

Answer 8

It is the permanent increase in size, dry mass and the number of cells in an organism.

Question 9

What is reproduction?

Answer 9

Organisms are able to produce offspring of the same specie as themselves.

Question 10

What is excretion?

Answer 10

Organisms are able to excrete metabolic waste, waste substances and excess substances from their bodies.

Question 11

What is nutrition?

Answer 11

Organisms take nutrients from their surroundings and use it for energy, growth and development.

Question 12

Name the characteristics of the Kingdom Plantae.

Answer 12

• eukaryotic
• have chlorophyll
• cell wall of cellulose
• sexual + asexual
• autotrophic
• multicellular

Question 13

Name the two classes of the phylum flowering plants (angiosperms).

Answer 13

monocotyledons (one seeds lobe)
dicotyledons (two seed lobes)

Question 14

State visible external diagnotic features of monocotyledons for:
- seeds
- leaves
- veins
- roots
- flowers

Answer 14

• one seed lobe (cotyledon)
• long, narrow & strap-shaped
• parallel veins
• adventitious/fibrous root system
• multiples of 3

Question 15

State visible external diagnotic features of dicotyledons for:
- seeds
- leaves
- veins
- roots
- flowers

Answer 15

• 2 seeds lobes (cotyledons)
• broad leaves
• network/branching pattern
• taproot system
• multiplies of 4/5

Question 16

Name the 4 Phylums of Animalia.

Answer 16

• mollusca
• annelida
• arthropoda
• chordata

Question 17

Name the characteristics of Animalia.

Answer 17

• multicellular
• eukaryotic
• no cell walls
• no chloroplasts
• muscles + nerves

Question 18

Name the 4 classes of Arthropoda.

Answer 18

• insecta
• arachnida
• crustacea
• myriapoda

Question 19

Name the 5 classes of Chordata.

Answer 19

• mammalia
• aves
• reptilia
• amphibia
• pisces

Question 20

Name the 2 orders of Myriapoda.

Answer 20

diplopoda
chilopoda

Question 21

Outline the 3 visible diagnostic features of Arthropoda.

Answer 21

• segmented bodies
• jointed limbs
• exoskeleton

Question 22

Outline the external diagnostic features of Annelida.

Answer 22

• segmented worms
• fixed number of similar segments (metameric
  segmentation)
• move with bristles, called chaetae
• covered with a non-chitinous cuticle

Question 23

Outline the diagnostic external features of Mollusca.

Answer 23

• soft, unsegmented bodies
• have a hump covered by a mantle
• mantle secretes a shell
• large muscular foot
• mouth with rasping tongue-like radula

Question 24

State the 5 classes of vertebrates.

Answer 24

mammalia
reptilia
aves
amphibia
pisces

Question 25

Outline the visible external diagnostic features of Arthropoda.

Answer 25

- they have jointed limbs - they have segmented bodies - they are covered with an exoskeleton made up of chitin.

Question 26

Outline the visible external diagnostic features of Insecta.

Answer 26

- 3 segments, namely head, thorax & abdomen - 3 pair of legs - 2 pairs of wings - 1 pair of compound eyes - 1 pair of antennae

Question 27

Outline the visible external diagnostic features of Crustacea.

Answer 27

- 2 body sections, namely cephalothorax and abdomen - 5 or more pairs of legs - 2 pairs of antennae - exoskeleton hardened by calcium salts - compound eyes on stalks - dorsal part of body is covered by hard shields called carapace

Question 28

Outline the visible external diagnostic features of Arachnida.

Answer 28

- 2 body segments, namely cephalothorax and abdomen - 4 pairs of legs - chelicerae with poison - 8 simple eyes - leathery exoskeleton

Question 29

Outline the visible external diagnostic features of Myriapoda.

Answer 29

- 2 body parts, namely head and trunk - jointed legs - 1 pair of antennae - long segmented trunks - metameric segmentation

Question 30

Name the 2 orders of Myriapoda.

Answer 30

centipedes millipedes

Question 31

Outline the visible external diagnostic features of Centipedes.

Answer 31

- flattened bodies - 1 pair of legs per segment - 1 pair of long antennae - carnivorous with poison claws and strong mouths

Question 32

Outline the visible external diagnostic features of Millipedes.

Answer 32

- rounded bodies - 2 pairs of legs per segment - 1 pair of short antennae - herbivorous with strong mouthparts to eat plants

Question 33

Name the characteristics of vertebrates.

Answer 33

- have a backbone - well-differentiated head - internal skeleton made of bone

Question 34

Outline the visible external diagnostic features of bony fish (Osteichthyes).

Answer 34

- absorb oxygen through gills covered in operculum - mouth opening present at anterior tip - fins for swimming and balancing which are supported by bony rays - have lateral veins for detecting vibrations - have thin bony plates (scales) which cover their bodies

Question 35

Outline the visible external diagnostic features of Pisces.

Answer 35

- limbless -coldblooded - gills + fins - marine / freshwater

Question 36

Outline the visible external diagnostic features of cartilaginous fish (Chondrichthyes).

Answer 36

- absorb oxygen through gills that are exposed by gill slits and are not covered by operculum - wide mouth opening is in ventral position to underside of body - have fins for moving forward/backward/turning and is supported by cartilage rods - skin is covered in tiny tooth-like scales

Question 37

Outline the visible external diagnostic features of Amphibia.

Answer 37

- smooth, moist skin - terrestrial animals that breed in water and lay soft jelly-like eggs that hatch into tadpoles with gills - adults breathe with lungs and use their skin for gaseous exchange

Question 38

Outline the visible external diagnostic features of Reptilia.

Answer 38

- tough, dry, scaly skin protected by overlapping scales - terrestrial animals that lay eggs with tough, leathery shells - have 4 limbs (snakes - no limbs)

Question 39

Outline the visible external diagnostic features of Aves.

Answer 39

- skin covered by feathers - feet covered by scales - toothless beakes - forelimbs are modified as wings - they lay hard-shelled eggs with food store (yolk) and calcareous shells

Question 40

Outline the visible external diagnostic features of Mammalia.

Answer 40

- skin covered by hair or fur - mammary glands present with milk to feed young - external earflaps (pinnae)