Topic 6 Predation

Question 1

What are the two broad categories of predators?

Answer 1

• Those that pursue their prey
• Those that wait for their prey

Question 2

What abilities are needed for predators that pursue their prey?

Answer 2

• Raw speed
• Stealth
• Cryptic (camoflauge)

Question 3

What abilities are needed for ‘sit-and-wait’ predators?

Answer 3

• Cryptic (camoflauge)
• Fast movement for striking
• Physiological apparatus that allows them to wait for passing prey
• Possibly toxins
• Possibly features to attract prey

Question 4

What abilities to prey need to stand the best chance of evasion from predators?

Answer 4

• Alert to movement
• Fast movement
• Well defended

Question 5

What are neuromuscular junctions?

Answer 5

The junctions between nerves and muscles.

Question 6

Name some major components of snake venoms.

Answer 6

• Phospholipases
• Proteases
• Phosphatases
• Hyaluronidases
• Neurotoxins

Question 7

What is the mode of action of neurotoxins and what effect do they have on tissues?

Answer 7

Neurotoxins bind strongly to receptor molecules that recieve chemical messages from neurons. They block the transmission of signals from nerves to muscles, causing paralysis.

Question 8

What are two characteristics of spiders that make them successful at subduing prey often larger and stronger than themselves?

Answer 8

• The capacity to make silk, a protein they use to form traps and webs
• The production of various poisons which immobilise, but may not kill, their victims.

Question 9

What are alkaloids?

Answer 9

A large and diverse group of chemicals, containing nitrogen, often produced as secondary chemicals. They are important components of toxins.

Question 10

Give some examples of alkaloids.

Answer 10

• Caffeine
• Morphine
• Nicotine

Question 11

What are neurotransmitters?

Answer 11

Chemicals used for communication between nerves or between nerves and muscle e.g., acetylcholine

Question 12

What is acetylcholine?

Answer 12

A neurotransmitter, found across a wide range of organisms, and especially important at neuromuscular junctions.

Question 13

What type of alkaloids can bind to acetylcholine receptor molecules on the surface of muscle cells?

Answer 13

Curare alkaloids

Question 14

What is an ecological community?

Answer 14

A set of interacting organisms in one location.

Question 15

What are trophic cascades?

Answer 15

Changes in abundance of species at one trophic level due to changes in abundance at a higher or lower trophic level.

Question 16

What are allometric relationships?

Answer 16

Changes in an organism function with body size.

Question 17

What is a power-law relationship?

Answer 17

Relationbships between two variables in which the dependent variable is raised to a particular power of the independent variable.

Question 18

Define correlation.

Answer 18

A statistical term describing the change of two variable together.

Question 19

What can be analysed in teeth of animals to provide information on diet?

Answer 19

Analysis of ratios of stable isotopes (e.g., carbon).