the living world

Question 1

What is an ecosystem?

Answer 1

An ecosystem is a unit that includes all the biotic (living) and abiotic (non-living) factors in an area.

Question 2

What is a producer?

Answer 2

A producer is an organism that uses sunlight to produce food.

Question 3

What is a consumer?

Answer 3

A consumer is an organism that gets its energy by eating other organisms (producers or consumers).

Question 4

What is a food chain?

Answer 4

A food chain shows how each organism gets its energy.

Question 5

What is a food web?

Answer 5

A food web shows how lots of food chains interconnect.

Question 6

What is a decomposer?

Answer 6

A decomposer is an organism that gets its energy by breaking down dead material. Bacteria and fungi are examples.

Question 7

What is a population?

Answer 7

A population is a group of the same species within a habitat.

Question 8

What is a community?

Answer 8

A community is the combination of life found in a particular habitat.

Question 9

What is a biome?

Answer 9

A biome is a unique combination of abiotic factors.

Question 10

What is the biosphere?

Answer 10

The biosphere is the thin layer on the surface of the planet that contains all life on Earth.

Question 11

What is nutrient cycling?

Answer 11

nutrient cycling:

• biomass (plants and organisms) die
• nutrients in litter (layer of decaying vegetation) are released as they decompose
• the nutrients in the soil is taken up by the plants and organisms eat them

Question 12

What is the pond margin?

Answer 12

The pond margin is where there is plenty of light, shelter and oxygen, on the side of the pond.

Question 13

Give the template for a food chain.

Answer 13

producer -> primary consumer -> secondary -> tertiary -> apex predator -> decomposer

Question 14

Give an example of a food chain for a pond.

Answer 14

food chain for a pond:

solar energy, nutrients
algae, bullrush, water lily
beetles, fleas, tadpoles
dragonfly, frogs, stickleback
kingfisher, heron, duck
water worms, rat-tailed maggot, pond snails

Question 15

Where are Savannah grasslands found? What are their characteristics?

Answer 15

Savannah grasslands are found between the tropics (23.5N/S). There are distinct wet and dry seasons but rainfall is relatively low. Most vegetation is grass with scattered trees.

Question 16

Where are temperate grasslands found? What are their characteristics?

Answer 16

Temperate grasslands are found at higher latitudes. There is more variation in temperature and less rainfall. There is no trees, just grasses.

Question 17

Where are temperate deciduous forests found? What are their characteristics?

Answer 17

Temperate deciduous forests are found mainly in the mid latitudes. There are four distinct seasons. There’s rainfall all year round. Summers are warm and winters are relatively mild. Deciduous trees lose their leaves in winter.

Question 18

Where are tundras found? What are their characteristics?

Answer 18

Tundras are found above 60 N in northern Europe, Alaska and northern Canada. Winters are very cold, summers are brief and there is little rainfall. There is hardly any trees and vegetation includes moss, grass and low shrubs. There’s a layer of permanently frozen ground called permafrost.

Question 19

Where are polar regions found? What are their characteristics?

Answer 19

Polar regions are found around the north and south poles. They are very cold, icy and dry. Not much grows at all and they remain dark for several months. Growing season is very short - about 2 months.

Question 20

Where are hot deserts found? What are their characteristics?

Answer 20

Hot deserts are found between 15-35 N/S of the equator. There is little rainfall. It’s very hot during the day and very cold at night. Shrubs and cacti are sparsely dispersed.

Question 21

Where are tropical rainforests found? What are their characteristics?

Answer 21

Tropical rainforests are found around the equator between the tropics. It’s hot and wet all year. There is lots of forests with dense canopies of vegetation with distinct layers.

Question 22

What is the climate like in tropical rainforests?

Answer 22

The climate in tropical rainforests is the same all year. It’s 20-28 degrees Celsius all year as the sun is overhead all year. Rainfall is 2000mm per year.

Question 23

What is the soil like in tropical rainforests?

Answer 23

In tropical rainforests, the soil isn’t fertile as heavy rain washes the nutrients away. There are nutrients at the surface due to decayed leaf fall, but this is very thin as decay is fast in the warm, moist conditions.

Question 24

What is the vegetation like in tropical rainforests?

Answer 24

In tropical rainforests, the trees are mostly evergreen (they don’t drop leaves in a particular season) to take advantage of the continual growing season. Many trees reach very high to take advantage of the sun, so very little reaches the floor.

Question 25

What are epiphytes?

Answer 25

Epiphytes grow on other living plants and take nutrients and moisture from the air.

Question 26

What is the structure of the vegetation in tropical rainforests?

Answer 26

The shrub layer is 5m or less. Little sunlight, so decomposition and small vegetation is here.
The under canopy is 5-15m. There is limited sunlight, so small trees wait for trees in the canopy to die and grow in their place.
The canopy is 15-30m and is very leafy. There is sunlight and it contains mammals and birds.
The emergents are 15-30m. There is the most sunlight.

Question 27

What is the tropical rainforest nutrient cycle?

Answer 27

Trees shed their leaves all year round. Decaying vegetation decomposes rapidly due to moist and warm conditions, rapidly releasing nutrients. The nutrients enter the soil surface, and shallow roots take up the nutrients quickly. The nutrients help the tree to grow rapidly.

Question 28

What are some adaptions of vegetation in tropical rainforests?

Answer 28

vegetation adaptions in tropical rainforests:

• lianas are rooted to the ground but are carried by trees into the canopy where they grow leaves
• buttress roots have massive ridges to help support the base of tall trees and help transport water and increases surface area for oxygen and carbon dioxide exchange
• leaves have flexible bases to turn towards sunlight
• leaves have drip-tips and waxy surface so heavy rainfall can drip off of the leaf, preventing damage and the growth of algae which could stop photosynthesis
• smooth bark allows water to flow down and prevents growth of other plants on it
• fast growing tress, like capoc, reach sunlight first

Question 29

What are some adaptions of animals in tropical rainforests?

Answer 29

animal adaptions in tropical rainforests:

• strong limbs (howler monkeys) so they can climb and leap from trees
• flaps of skin (flying squirrels) so glide between trees
• suction cups (red-eyed tree frogs) for climbing
• short, pointy wings to easily move between dense leaves on trees
• camouflaged
• nocturnal (sloths) to save energy when cooler
• adapted to low light levels on floor (anteaters have sharp smell and hearing)

Question 30

Why does deforestation occur?

Answer 30

why deforestation occurs:

• population pressure
• mineral extraction
• energy development
• commercial logging
• commercial farming (for global)
• subsistence farming (for personal reasons)

Question 31

Why is it important to preserve tropical rainforests?

Answer 31

importance of preserving tropical rainforests:

• protect biodiversity
• products like rubber, coffee, chocolate and medicines are sourced here
• to keep ecotourism
• reduce climate change

Question 32

How does selective logging sustainably manage tropical rainforests?

Answer 32

selective logging:

• only some trees are cut down
• this is less damaging as most trees are left standing

Question 33

How does ecotourism sustainably manage tropical rainforests?

Answer 33

ecotourism:

• minimises damage to the environment
• has economic and social benefits
• only small amount of people are allowed to visit at a time to minimise litter and waste
• local people won’t have to rely on logging and farming as their source of income
• successful in Costa Rica, largest source of income for country

Question 34

How does replanting sustainably manage tropical rainforests?

Answer 34

replanting:

• plant new trees to replace the cut down ones
• make sure it’s the same tree to keep diversity
• laws for this in some countries

Question 35

How does reducing debt sustainably manage tropical rainforests?

Answer 35

reducing debt:

• countries that owe money to others agree to reduce the amount of debt if they conserve their rainforest
• in 2008, USA reduced Peru’s debt by $25 million in exchange for rainforest conservation

Question 36

How does education sustainably manage tropical rainforests?

Answer 36

education:

• local people may not understand the true impacts of deforestation
• teach local people alternative ways of making money
• educate people to buy things that are certified by sustainably managed sources

Question 37

How does conservation sustainably manage tropical rainforests?

Answer 37

conservation:

• set up natural parks and reserves
• Norway paid $1 billion into Brazil’s Amazon fund to be used for conservation

Question 38

How does international hardwood agreements sustainably manage tropical rainforests?

Answer 38

international hardwood agreements:

• promoting sustainably managed forests
• the Forest Stewardship Council is an organisation made up of businesses, non-governmental organisations and individuals, who mark their products with a logo to show which products are sustainably produced

Question 39

What is the climate like in hot deserts?

Answer 39

In hot deserts, there is very little rainfall (less than 250 mm per year). Temperatures are extreme (45-5 degrees Celsius).

Question 40

What is the soil like in hot deserts?

Answer 40

In hot deserts, the soil is shallow with a coarse, gravelly texture. The soil isn’t fertile as there is hardly any leaf fall. The soil is dry due to the lack of rainfall and plant material.

Question 41

What are the people like in hot deserts?

Answer 41

In hot deserts, the people grow crops where there are natural springs or wells to supply natural water. People are often nomadic, so they travel all the time in search of food and water.

Question 42

What are some adaptations of plants in hot deserts?

Answer 42

plant adaptations in hot deserts:
- plant roots are extremely long to reach very deep water supplies
- plant roots spread out very wide near the surface to
catch as much water as possible when it rains
- many plants are succulents (eg. cacti). they have large stems for storing water and thick waxy skin to reduce water loss
- sharp spines and toxins to stop animals stealing water
- small leaves or spines reduces transpiration
- some seeds only germinate when it rains

Question 43

What are some adaptions of animals in hot deserts?

Answer 43

animal adaptions in hot deserts:

• nocturnal as to save energy
• long limbs or ears to lose energy quicker
• lizards and snakes are able to survive high body temperatures
• bigger animals store large amounts of fat which they can break down into water when needed
• some animals get all the water they need by eating
• camels have triple eyelids, long eyelashes and can close nostrils to keep sand out

Question 44

What is desertification?

Answer 44

Desertification is the degradation of land so that it becomes drier and less productive.

Question 45

What are the six causes of desertification?

Answer 45

causes of desertification:
- rainfall - less rainfall, so plants die. plant roots hold soil together, so if die, easily eroded. climate change is causing reduced rainfall

• temperatures - higher, more water evaporates, soils drier so plants die
• removal of fuel wood - soil is exposed, easily eroded
• overgrazing - cattle or sheep eat plants faster than they can regrow, so soil erosion as roots don’t hold soil together
• overcultivation - if crops planted in same area continuously, all nutrients get used up so plants can no longer be grown, so erosion increases
• population growth - puts pressure on land, leading to more deforestation, more overcultivation and more overgrazing

Question 46

What are four ways to reduce the risk of desertification?

Answer 46

reduce risk of desertification:
- water management - growing crops that don’t need much water, use drip irrigation so the soil isn’t eroded

• tree planting - protect soil from wind erosion, protects smaller crops by providing shade
• soil management - leaving areas to rest in between grazing or planting, rotate crops that use different nutrients, use compost to add extra nutrients
• appropriate technology - sand fences trap windblown sand, terraces stabilise the soil and reduce erosion, solar cookers use sun’s energy to heat food rather then deforestation