2. Ecology pt1

Question 1

Explain some adaptations that help plants store water?

Answer 1

Some plants survive long, dry periods by storing water in:

1. fleshy leaves
2. Fat stems: wrinkle stems flatten out when it absorbs rain
3. Roots

Question 2

What’s competition?

Answer 2

• The combat between individuels for resources (food, etc)
• it happens when there’s no enough of a resource to satisfy the needs of all the individuals dependant on it
• those who unsuccessfully compete die or fail to reproduce

Question 3

What 4 things do animals mostly compete for?

Answer 3

• food
• water
• space to nest
• mates

Question 4

What are the 2 types of competition?

Answer 4

• intraspecific competition

- interspecific competition

Question 5

What’s infraspecific competition?

Answer 5

• happens between individuals of the same species
• as resource become limited, those best adapted to get them will survive to reproduce
• the less adapted die off of fail to reproduced (basically natural selection)

Question 6

What happens if the population of a species decreases?

Answer 6

• competition reduced and numbers rise again

- if the population then increases too much, then competition increases and numbers are reduced again. (Repeat)

Question 7

What’s interspecific competition?

Answer 7

• this happens between the individuals of different species
• this can affect the population size of a species and its distribution in an ecosystem
• if 2 species occupy the same status within an environment the more successful at obtaining resources will out-compete the other and may cause its extinction

Question 8

So explain briefly what would happen if you have 2 species occupy the same status within an environment?

Answer 8

• both species grow slowly as they’re sharing food

- eventually one will outcompete the other driving it into extinction

Question 9

What 3 things do plants mostly compete for?

Answer 9

• sunlight
• nutrients
• water

Question 10

What do plants do to reduce competition and increase they’re survival chances?

Answer 10

they disperse their seeds as far as possible:

• having fruits/nuts/berries to tempt animals to eat them, after it’s eaten the seed is deposited in faeces which acts as fertilised
• sticking to or hooking into animal fur so they’re carried a long distance
• some seeds can catch the wind and be blown as far as possible eg. Danilions
• some can float in water for a long time eg. Coconuts

Question 11

What’s a food chain and how does it work?

Answer 11

• they display the feeding relationship in an ecosystem. The arrows show the movement of energy
• start with a producer: a plant
• organism that eat the plant are called primary consumers
• any organism which eats the primary consumer is a secondary consumer
• then it goes tertiary and quaternary up to top consumer

Question 12

What’s a food web?

Answer 12

-it shows the variety of food an organism eats and its composition with other species fir food

Question 13

In an ecosystem what would happen to the grass is all the sheep died of a disease?
And what would happen to the rabbit who like the sheep also eat grass?

Answer 13

• the grass would increase as there’s less sheep eating it

- the number of rabbit would increase as there would be more grass and reduce interspecific competition

Question 14

What’s biomass?

Answer 14

• The dry mass of living material in an animal or plant
• all the energy to form biomass comes from the light energy from the sun
• it’s absorbed by chlorophyll in plants, which is used in photosynthesis to make chemical energy in the plant matter
• which is passed onto the animals that eat it

Question 15

What’s a pyramid of biomass?

Answer 15

• a scale diagram displaying the relative amount of biomass in each level of a food chain
• trophic level 1 is at the bottom of the pyramid

Question 16

Explain why biomass is reduced along a food chain?

Answer 16

As there’s less energy available for each stage

Question 17

Explain why there’s less energy along each stage in a biomass pyramid ?

Answer 17

1. Not all the organism in a stage are eaten by the stage above, they could die naturally so that energy is lost
2. Some material is lost as faeces (mostly in herbivores where they struggle to digest the plant material they eat) carnivores are more efficient but excess protein can be wasted by passing out as urea in urine
3. Most the biomass is used for respiration to release energy

Question 18

Explain what the energy released from respiration is used for?

Answer 18

• Movements -as the muscles contract they use up lots of energy
• heating- muscle contraction and chemical reactions produce hear which is given off to surroundings -warm blooded animal release more heat so need to eat more to replace the lose energy

Question 19

What’s a Predator?

What’s a prey?

Answer 19

• predators are animals that kill and eat other animal for food
• prey are animals killed by predators

Question 20

What happens when there’s a small amount of prey?

Answer 20

The predators may starve

Question 21

What do decomposers do?

Answer 21

• they recycle nutrients from organisms in the food chain back into the soil
• as plants remove nutrient from the soil they have to be replaced for future plants

Question 22

Explain the decomposition cycle

Answer 22

• animal excretion is decomposed
• When the animal dies it’s decomposed
• decomposers produce nutrients for plants
• when plants die or a leaf falls its decomposed
• or the plant provides food for the animal

Question 23

What do you call animal that live off dead matter give some examples?

Answer 23

• detritus feeders (or detritivores)
• maggots abs worms
• the begin the decay process by feeding and the excreting waste

Question 24

What are microorganism role in the decay process?

Answer 24

• eg bacteria and fungi
• they use the dead matter or waste (excreted by the detritus feeders) for their own growth
• releasing CO2, water and nutrients into the soil such as mineral ions that plants need for further growth

Question 25

What conditions affect the speed for decay?

Answer 25

• temperature
• water
• availability of oxygen

Question 26

Explain why how the temperature effects the speed of decay

Answer 26

• decay generally increases under warm conditions as the enzymes involved are more active
• but it may stop if it gets too hot as it damages the shape of the enzymes and can denature it

Question 27

Explain why how the moisture can effect the speed of decay?

Answer 27

-microorganisms grow better under moist conditions as they can dissolve their food better. This causes decay to speed up

Question 28

Explain why how the oxygen concentration effects the speed of decay?

Answer 28

• most microorganisms require oxygen to survive and release energy from their food (aerobic respiration)
• so decay will speed up if there’s a good supply of oxygen

Question 29

What are uses if decomposers?

Answer 29

• compost heaps
• sewage treatment
• biogas generators

Question 30

Explain how compost heaps uses decomposers?

Answer 30

• compost heaps encourage decomposers to beak down waste organic matter such as grass, leaves and vegetable waste
• once the microorganisms have broken down the waste and released the nutrients, the remains can be used as a fertilised