Topic 12: Predation

Question 1

What is the interaction between predator and prey?

Answer 1

predators often regulate the numbers of their prey and the prey often regulate the numbers of predators.

Question 2

What is optimal foraging theory?

Answer 2

optimal foraging theory applies a cost benefit all decisions.
minimize the cost while maximizing the gains.

Question 3

What is (in general terms) the red queen hypothesis?

Answer 3

if both species (prey + predator) are moving forward at the same speed, they stay in “place”. if one stops or the other moves too far ahead the other can face trouble.

Question 4

What are the 3 generalized predator hunting tactics? give an example of a predator for each tactic.

Answer 4

1. ambush - low frequency of success but minimal energy spent. (low chance of success bc waiting for prey to come to you. most ambush predators are poikilotherms).
   - ex: crocs.
2. stalking - high search time but short pursuit time.
   - ex: cats, polar bears.
3. pursuit - low search time, but extended pursuit time. (chase prey to exhaustion)
   - ex: wolves.

Question 5

What kind of adaptions can predators use to aid in their capture of prey?

Answer 5

• cryptic coloration to avoid detection or blur their outlines from their prey.
• aggressive mimicry to resemble their prey.
• cooperative behaviour to take down larger prey.
• chemical attacks like poisons and toxins to debilitate or kill prey.

Question 6

What kind of adaptations can prey use to avoid predators?

Answer 6

• chemical defences: alarm messages and noxious concoctions.
• cryptic coloration: colours and patterns that allow prey to blend into the background.
• resemblance to inanimate objects.
• flash colouration: distracts and disorients predators.
• warning coloration: bold colours and patterns that may serves a warning to would be predators.
• structural defences focused on armoured protection
• behavioural defences

Question 7

What is modularity?

Answer 7

Modularity allows loss of body parts without compromising survival.

Question 8

What are some plant physical defences against herbivores?

Answer 8

1. physical defences: waxy coatings, spines, thorns, and prickles.
2. low nutrient value: allocating growth to tissues which are low in nutrients.
3. mimicry: plant can avoid herbivory by mimicking another unpalatable plant.

Question 9

Most plant defences are biochemical. Discuss alkaloids. Give an example of a plant that has this.

Answer 9

alkaloids are nitrogen based molecules that are bitter-tasting compounds.
ex- tabbaco plant.

Question 10

Most plant defences are biochemical. Discuss terpenoids. Give an example of a plant that has this.

Answer 10

oils, latex, and resins based on a 5 carbon isoprene. these have nice fragrance and smells.
ex- ginger root and cinnamon.

Question 11

Most plant defences are biochemical. Discuss phenolic compounds. Give an example of a plant that has this.

Answer 11

main defence is microbial. typically found in fruits bc it is an environment rich for bacteria and unfit to grow in but the phenolic compound prevents this. the phenolic compounds also prevent the grapes from rotting/decaying, bc the fruit wants herbivory so that the seeds spread.
ex- grapes.

Question 12

Most plant defences are biochemical. Discuss signalling.

Answer 12

signal transduction pathways with terpenoids and jasmonic acid.