3.3 Plant and Animal Responses

Question 1

What is tropism?

Answer 1

A growth response towards or away from an environmental stimulus in one direction (plants)

Question 2

What is auxin?

Answer 2

Auxin is a plant growth hormone that controls the tropic response, it causes elongation

Question 3

How does auxin affect roots?

Answer 3

Low concentrations stimulate, high concentrations inhibit

Question 4

How does auxin affect lateral buds?

Answer 4

Low concentrations stimulates, high concentrations inhibit

Question 5

How does auxin affect stems?

Answer 5

High concentrations stimulate, low concentrations inhibit

Question 6

What is etiolation?

Answer 6

When in low light shoots grow faster and the stem becomes elongated to maximise stem length so that the plant may grow to a lighter area.

Question 7

Where does auxin accumulate?

Answer 7

The shaded/lower sides of the plant root/shoot

Question 8

What is the mechanism of a plant working towards positive phototropism?

Question 9

What are nastic responses?

Answer 9

Non-directional responses to stimuli (plants)

Question 10

What is taxes?

Answer 10

The movement of the whole animal towards or away from a stimulus

Question 11

What is Kinesis?

Answer 11

A non directional response to stimuli (animal)

Question 12

What are the 3 main reasons for animals’ behaviour?

Answer 12

Food, Shelter, Mates

Question 13

What are the mechanisms of gravitropism in seedlings?

Question 14

What is gibberellin?

Answer 14

The hormone responsible for the germination of seeds, stimulation of flowering, and breaking dormancy in seeds and buds

Question 15

What is homing?

Answer 15

The ability of an individual to return back to the home site

Question 16

What is migration?

Answer 16

Annual mass movements made by animals from their breeding area to feeding area

Question 17

What are the triggers to migration?

Answer 17

1. A drop in temperature
2. Days become shorter, which triggers migratory restlessness
3. Innate genetic drive
4. The desire to reproduce

Question 18

What are the methods of navigation used in animals?

Answer 18

1. Visual Cues
2. Solar Navigations
3. Magnetic fields
4. Star Navigation
5. Chemical Navigation
6. Sound as sonar

Question 19

How does solar navigation work?

Answer 19

It is an inbuilt clock that can help to determine direction, using the fact that the sun moves east to west during the day.

Question 20

What is an exogenous rhythm?

Answer 20

A rythym controlled by the external stimuli detected by the organism

Question 21

What is an endogenous rhythm?

Answer 21

A rythym controlled by an internal biological clock and maintained even when zeitgebers are removed

Question 22

What is entrainment?

Answer 22

When biological clocks reset on a regular basis with zeitgebers, forcing it to take up the new period of environment

Question 23

What are the adaptive advantages of circadian rythyms?

Answer 23

1. Sychronise with food/prey
2. Avoid Predators/unfavourable conditions

Question 24

Biological clocks are?

Answer 24

Innate, genetically determined

Question 25

What are the adaptive advantages of circaannual rhythms?

Answer 25

1. Synchronise with seasons 2. Breeding in favourable conditions 3. Migrating to avoid unfavourable conditions

Question 26

Photoperiods in animals are controlled by?

Answer 26

The pineal gland and SCN

Question 27

What is a zeitgeber?

Answer 27

Environmental cues that train the internal biological clock

Question 28

What is phytochrome?

Answer 28

A pigment in leaves that absorbs 2 wavelengths of light, Pr Pfr

Question 29

What is a short-day plant?

Answer 29

Plants that require short days and long nights (low con. of Pfr)

Question 30

What is critical day length?

Answer 30

The time of day length required for a plant to flower

Question 31

What is a long-day plant?

Answer 31

Plants that require a long day and short night to flower (high con. of Pfr)

Question 32

What does Pr absorb?

Answer 32

red light, from the sun

Question 33

What does Pfr absorb?

Answer 33

Far-red light, night only has far red light

Question 34

Describe the phytochrome diagram

Question 35

How is the light detected?

Answer 35

By the leaves, which uses florigen to pass the messages to the buds

Question 36

Describe short day plants in winter

Answer 36

Pr accumulates to high levels, stimulating them to flower (due to low con. Pfr)

Question 37

Describe long day plants in summer

Answer 37

Pr reaches low levels , stimulating them to flower (due to high con. Pfr)

Question 38

What are interspecific relationships?

Answer 38

Interactions with other species

Question 39

What are intraspecific relationships?

Answer 39

Interactions between one species

Question 40

Describe mutualism

Answer 40

Species A and B benefit

Question 41

Describe commensalism

Answer 41

Species A benefits, Species B is not affected

Question 42

Describe antibiosis

Answer 42

Species A is harmed and Species B is not affected

Question 43

Describe exploitation

Answer 43

Species A benefits, Species B is harmed

Question 44

Describe alleopathy

Answer 44

Occurs in plants only, Species aA benefits, Species B is harmed

Question 45

Describe competition

Answer 45

Both species are harmed

Question 46

Describe the specifics of exploitation

Answer 46

Grazing: Plants eaten by many organisms Predation: Predator v Prey Parasitic: Parasites take resources from the host

Question 47

What is Gauses' principle of competitive exclusion?

Answer 47

"When two species have exactly the same way of life (ecological niche) they will not be able to co-exist."

Question 48

What is interspecific competition is reduced by?

Answer 48

Animals creating small differences in niches, such as eating on different parts of a tree or leaf, being nocturnal vs. diurnal, plants growing away from one another

Question 49

What is an Agnostic Behaviour?

Answer 49

Any social behaviour related to fighting (broader than just aggressive behaviour)

Question 50

What is ritualised fighting?

Answer 50

Non lethal organised fighting within a species to make sure there are is a winner and a loser without serious damage to damage survival

Question 51

When does the most vicious fighting occur?

Answer 51

Individuals that can't really hurt each other

Question 52

When does the most intense competition occur?

Answer 52

1. Interspecifically 2. Between the same sex when needing a mate

Question 53

How do species alleviate intraspecific competition? Why do they want to do this?

Answer 53

Creating hierarchies and territories. Competition benefits no-one so species will try to avoid it when possible to ensure their survival.

Question 54

What is a home range?

Answer 54

An area that an animal moves around to collect resources or travel across. it is not defended (Neighbourhood)

Question 55

What is a territory?

Answer 55

An area of the home range that is defended and marked (house)

Question 56

What are some of the adaptive advantages of territories?

Answer 56

- Reduces direct competition -ensures enough space and food for each animal holding territory - The most successful male has the most territories, meaning more genetically superior off spring

Question 57

How do animals mark their territory?

Answer 57

1. Vocal, birds singing 2. Mark with urine 3. Special scent glands 4. Waving claws/visuals