Animal Orientation Responses

Question 1

Define a taxis response

Answer 1

A movement of an animal towards or away from an environmental stimulus coming from one direction only

Question 2

Name the response - maggots move towards the smell of rotting meat

Answer 2

Positive chemotaxis

Question 3

Name the response - Mosquitos are attracted to body heat

Answer 3

Positive thermotaxis

Question 4

Explain why earthworms move away from light

Answer 4

An area of high intensity would cause their skin surface to desiccate which would limit their ability to carry out gas exchange.

Question 5

Define a kinesis response

Answer 5

A change in the movement of an animal in response to a change in the intensity of an environmental stimulus, not its direction

Question 6

Name the two types of kineses and what change occurs

Answer 6

Orthokinesis - a change in the animal’s speed

Klinokinesis - a change in the number of random turns by an animal

Question 7

Name the response - woodlice increase their number of random turns in response to increasing light intensities

Answer 7

Photokinesis or Klinokinesis

Question 8

Name the response - at high temperatures, human body lice increase their speed of movement

Answer 8

Thermokinesis or Orthokinesis

Question 9

Explain why woodlice increase their number of turns as light intensity increases

Answer 9

They are searching randomly to try and find a way out of high light intensities that desiccate their gas exchange surface

Question 10

Define homing

Answer 10

The daily return of an animal to its home bases usually after finding food

Question 11

Identify navigational methods used by species to ‘home’

Answer 11

Solar navigation
Landmarks
Scent
Earth's magnetic fields
Stellar navigation
Sonar navigation

Question 12

Define migration

Answer 12

The seasonal mass movement of a species from one location to another over long distances usually for the purpose of feeding and/or breeding

Question 13

Identify triggers for migration (when do they know to migrate)

Answer 13

Shortening photoperiod
Seasonal change related to temperature
Food availability
Sexual maturity
Genetic drive/Innate response

Question 14

Why is photoperiod a reliable cue compared to changing temperature with the seasons?

Answer 14

The length of the photoperiod is consistent from year to to year where as seasonal variations in temperature occur regularly which might trigger a species to migrate at the wrong time

Question 15

Name two key methods of preparation prior to migration in birds

Answer 15

Building up fat reserves

Replacement of feathers

Question 16

How does a species home or migrate using the earth’s magnetic fields?

Answer 16

They must have an internal compass to detect the field lines

Question 17

How does a species use solar navigation to home or migrate?

Answer 17

They orientate themselves to the position of the sun in the sky. They also must have an internal biological clock to adjust for the changing position of the sun in the sky throughout the day

Question 18

How does a species use stellar navigation to home or migrate?

Answer 18

They orientate themselves from the northern celestial pole as this is the star that doesn’t change its position in the night sky as the earth rotates.

Question 19

If a species migrates as part of their usual behaviour, the benefits must outweigh the costs. Identify the benefits of migration

Answer 19

Avoid a climate that may affect survival
Find a more consistent food source where there is less competition
Migrate to a similar place to find others for breeding
Migrate to a place where the energy costs to stay warm are less

Question 20

Identify the costs of migration

Answer 20

Energy cost while migrating leaves the individual in poor physiological condition for reproduction
Might get lost and not arrive to destination
Might get caught by predators