interactions between organisms - predation

Question 1

predator

Answer 1

an organism that feeds on another organism - its prey

Question 2

how predators have adapted

Answer 2

1) faster movement
2) more effective camouflage
3) increase in sensitivity of senses; sigh, hearing, smell
4) improvement in hunting strategies; stalking, sit and wait

Question 3

how preys have adapted

Answer 3

1) warning signals; alarming others in order for them to run away and hide
2) defensive weapons; poison, claws, quills etc
3) faster movement

Question 4

predation

Answer 4

when one organism is consumed by another

Question 5

predator-prey representation in a lab

Answer 5

• when prey and predator are brought into a laboratory, the prey is usually exterminated by the predator
• such evidence however, does not reflect what happens in the wild
• this is normally because due to the confined nature of the lab, making it difficult to successfully avoid predation

Question 6

predator-prey representation in nature

Answer 6

• prey-predator relationship would be more accurate if it were in nature due to the wide range of area they can travel to and the diverse environment
• however, it is difficult to obtain reliable data on natural populations because it is not possible to count all individuals present
• it can only be estimated by sampling and surveys, which still are not completely accurate

Question 7

effect of predator-prey relationship on population size

Answer 7

1) predators eat their prey, reducing the population of the prey
2) with fewer preys available, predators are in greater competition with each other to consume the preys left
3) predator population decrease as some individuals are unable to compete and therefore cannot obtain enough food to survive
4) with fewer predators left, fewer preys are eaten
5) the population of preys begins to increase
6) more prey are available now as food, predator population increases

Question 8

why fluctuations occur in a predator-prey relationship graph

Answer 8

• in a natural ecosystem, organisms eat a wide range of foods and therefore fluctuations in population size are less severe

Question 9

what factors cause fluctuations in population size

Answer 9

• disease
• climate
• immigration
• selection pressure

Question 10

selection pressure

Answer 10

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