Defense (1)

Question 1

Extrinsic ecological causes of mortality

Answer 1

• accidents
• predation (defense mechanisms)
• diseases (immune system)
• environmental stressors (tolerate, resist and repair)

Question 2

Ageing (Intrinsic)

Answer 2

• degeneration of systems, cells and molecules
• can be influenced by extrinsic factors
• can be repaired to a point

Question 3

Avoiding predators

Answer 3

• Diurnal/ vertical migration (in ground)
• Camouflage

Question 4

Main 2 types of camouflage

Answer 4

1. Crypsis
2. Masquerade

Question 5

Crypsis def

Answer 5

when colour or behaviour is employed to prevent detection when in plain sight

Question 6

Masquerade def

Answer 6

recognition is prevented by resembling an uninteresting object

Question 7

5 types of crypsis

Answer 7

1. Background matching
2. Countershading
3. Obliterative shading
4. Disruptive coloration
5. Distractive markings

Question 8

Background matching def

Answer 8

appearance generally matches the colour, lightness and pattern of background. Can be very specific

Question 9

Countershading def

Answer 9

where the upper body of the animal is darker than the bottom, which cancels out creation of shadows in directional light

Question 10

Obliterative shading

Answer 10

countershading obliterates (disguises) 3D form

Question 11

Disruptive coloration

Answer 11

when markings create the appearance of false edges and boundaries, making it difficult to detect or recognise animal’s
true outline and shape

Question 12

Distractive markings

Answer 12

Direct the ‘attention’ or gaze of the receiver from traits that would give away the animal (such as the outline)

Question 13

Dissuading and repelling predators methods

Answer 13

1. Flash colouration
2. Warning colouration (Aposematism)
3. Allomones (Chemicals)
4. Venom & other chemicals

Question 14

Aposematism

Answer 14

(Warning colouration)
- contradicts cryptic colouration
- warns predator that prey item is unprofitable

Question 15

Allomones eg. (anti-feeding & anti-fouling)

Answer 15

• Neurotoxins (nemerteans)
• Sulphuric acid (shell-less mollusks)
• Hydrogen cyanide (Biolum millipedes)

Question 16

Nemerteans

Answer 16

Ribbon worms

Question 17

Venom & other chemicals eg.

Answer 17

• Cnidocytes
• Bombadier beetle

Question 18

Anti-fouling (Callyspongia pulvinata) chemicals inhibit fouling by…

Answer 18

1. Disrupting the biofilm by killing diatoms
2. Inhibiting larval settlement & survival of polychaete larvae
3. Can release chemicals into water - not restricted to animals touching the sponge

Question 19

Externa physical threats can be overcome by

Answer 19

– Avoidance (daily activity patterns or camouflage)
– Dissuasion (strong outer coverings, chemicals that may be linked with warning colouration, or that prevent fouling or predation)
– Repellence (may utilise mechanisms that are usually used for feeding, or which simply frighten potential predators)

Question 20

Dissuasion

Answer 20

Trying to persuade something to not take part in an activity