YR2-CH18-LSN7

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 2

LESSON 7

TODAY:

• ECOLOGY THEORY: LOSS OF ENERGY IN A PYRAMID
• WORKING ON ASSIGNMENTS
  
• DISCUSSING ASSIGNMENTS
• FINISHING ECOLOGY

BIOMASS:

• BIOMASS: mass of all living organisms
• UNIT: mass per surface area per time (example tons / ha / yr)
• PRODUCED by PRODUCERS

PYRAMID of BIOMASS:

IN A PYRAMID OF BIOMASS

• the trophic level of producers ALWAYS has the highest biomass
• each higher trophic level the biomass is reduced by a factor 10.

WHY?

FLOW OF ENERGY

FLOW OF ENERGY

REASONS WHY ENERGY LOSS IS 90% PER TROPHIC LEVEL

1. Not all biomass is ingested
2. Not all biomass is absorbed
3. A lot of biomass is excreted
4. A lot of biomass is lost to respiration

Therefore JUST 10% of the biomass of a lower trophic level available for the next trophic level

Assignments on Classroom:

Fist 15 mins in silence

Assignments on classroom:

"Ecology lesson 7"

ANSWERS

Assignment 1 - R:

Fill in the gaps in the text below.

Producers are able to make their own ……...a………. . Producers are fed upon by herbivores or ……..b…….. consumers. These in turn provide food for ……..c…….. consumers. Dead and ….d….. material provides food for …..e….. and detritivores. Feeding relationships can be shown in food …..f….. and food …...g…… . Feeding relationships can also be shown in pyramids of …..h….., biomass and …...i…… . 

Assignment 1 - R:

Fill in the gaps in the text below.

Producers are able to make their own …FOOD…. . Producers are fed upon by herbivores or …PRIMARY.. consumers. These in turn provide food for …SECONDARY.. consumers. Dead and …ROTTEN.. material provides food for …DECOMPOSERS.. and detritivores. Feeding relationships can be shown in food …CHAINS.. and food …WEBS… . Feeding relationships can also be shown in pyramids of …NUMBERS.., biomass and …ENERGY… . 

Assignment 2 - T1:

Look at the woodland food web below: 

a) Give an example from the food web, of each of these:

i) A producer = 

ii) A primary consumer = 

iii) A secondary consumer = 

b) How many carnivores are there in the food web? ….

c) Name a food chain with 5 links in it.

                      ……-.......-.......-.......-.......

d) If all the spiders were killed by disease, what would happen to the numbers of...? Please explain your answer too:

i) moth larvae = 

ii) plants = 

Assignment 2 - T1:

Look at the woodland food web below: 

a) Give an example from the food web, of each of these:

i) A producer = PLANTS

ii) A primary consumer = APHID, MOTH LARVA, VOLE

iii) A secondary consumer = LADYBIRD, BLUE TIT, SPIDER, OWL, STOAT

b) How many carnivores are there in the food web? 6

c) Name a food chain with 5 links in it.

         PLANTS-APHID-LADYBIRD-BLUE TIT-OWL

d) If all the spiders were killed by disease, what would happen to the numbers of...? 

i) moth larvae = THERE NUMBERS WOULD RISE BECAUSE THERE IS ONE PREDATOR LESS TO HUNT THEM.

ii) plants = THERE NUMBERS MIGHT DROP BECAUSE OF THE INCREASED NUMBER OF PRIMARY CONSUMERS

Assignment 2 - T1:

Look at the food web below:

a) Looking at the foodweb, please name:

Two primary consumers:

b) Construct, using the food web, two different food chains, each with four links.

   ……-.......-.......-.......

   ……-.......-.......-.......

c) Why do most food chains begin with green plants?

d) If all the owls were killed what would happen to the numbers of…...? Please explain your answer in detail:

dormice = 

earthworms = 

Assignment 2 - T1:

Look at the food web below:

a) Looking at the foodweb, please name:

Two primary consumers:

b) Construct, using the food web, two different food chains, each with four links.

   ……-.......-.......-.......

   ……-.......-.......-.......

c) Why do most food chains begin with green plants?

d) If all the owls were killed what would happen to the numbers of…...? Please explain your answer in detail:

dormice = 

earthworms = 

Assignment 3 - T2:

The table below shows information about three different food chains:

Draw a pyramid of numbers for each food chain shown above. 

table

pyramid of numbers

table

pyramid of numbers

table

pyramid of numbers

Assignment 3 - T2:

The table below has the mass per organism included in it:

Complete the table below:

Draw a pyramid of numbers and of biomass for each food chain shown in the table above. (so 6 pyramids in total!) 

Assignment 3 - T2:

The table below has the mass per organism included in it:

Complete the table below:

Draw a pyramid of numbers and of biomass for each food chain shown in the table above. (so 6 pyramids in total!) 

table

pyramid of biomass

pyramid of numbers

table

pyramid of biomass

pyramid of numbers

table

pyramid of biomass

pyramid of numbers

Assignment 3 - T2:

What differences do you see between each pyramid of numbers and biomass.

Food Chain 1 difference: 

Food Chain 2 difference: 

Food Chain 3 difference: 

Assignment 3 - T2:

What differences do you see between each pyramid of numbers and biomass.

• Food Chain 1 difference: THE PYRAMID OF NUMBERS HSS A CLEARER PYRAMID SHANE THAN THE PYRAMID OF BIOMASS.
• Food Chain 2 difference: THE PYRAMID OF BIOMASS HAS A CLEAR PYRAMID SHAPE THE PYRAMID OF NUMBERS DOES NOT.
• Food Chain 3 difference: THE PYRAMID OF BIOMASS HAS A CLEAR PYRAMID SHAPE THE PYRAMID OF NUMBERS DOES NOT.

Assignment 4 - I:

1. The following questions are about cacti, these plants have adapted to live in deserts. 

a) In which of the two following ways are the cacti adapted to living in deserts. Choose two from below and explain your choices: Flat leaves / Fleshy stem / Many stomata / Thick waxy cuticles

b) i) Name the process by which water is lost from plants.

ii) Stomata are small holes in the leaves and the stems of the cacti that can open and close. With cacti these holes only open at night. Suggest why?

c) Cacti have very small green leaves, but the stems of the cacti also contain a lot of chlorophyl. Suggest why?

d) Many cactus flowers are closed at midday. Suggest why?

Assignment 4 - I:

1. The following questions are about cacti, these plants have adapted to live in deserts. 

a) In which of the two following ways are the cacti adapted to living in deserts. Choose two from below and explain your choices: 

Flat leaves : NOT AN ADAPTATION

Fleshy stem : HOLDS THE MOISTURE BETTER

Many stomata : NOT AN ADAPTATION

Thick waxy cuticles ; STOPS THE PLANT FROM DRYING OUT

b) i) Name the process by which water is lost from plants.

EVAPORATION

ii) Stomata are small holes in the leaves and the stems of the cacti that can open and close. With cacti these holes only open at night. Suggest why?

TO PREVENT EVAPORATION

Assignment 4 - I:

c) Cacti have very small green leaves, but the stems of the cacti also contain a lot of chlorophyl. Suggest why?

SO THAT THEY KEEP THE LEAVES SMALL TO PREVENT EVAPORATION.

d) Many cactus flowers are closed at midday. Suggest why?

TO PRVENT THE EVAPORATION OF THE NECTAR FROM THE FLOWERS.

HW FOR LESSON 8

WORK THROUGH THE PRESENTATION ON LESSONUP CALLED:

YR2-B5-HW8