Y11 Autumn Term Biology Round Up

Question 1

What is an environment?

Answer 1

The conditions surrounding an organism (abiotic and biotic)

Question 2

What is a habitat?

Answer 2

A place where organisms live (eg. woodland, lake)

Question 3

What is a population?

Answer 3

Individuals of a species living in a habitat

Question 4

What is a community?

Answer 4

Populations of different species living in a habitat. Organisms require a supply of materials from their surroundings as well as other living organisms

Question 5

What is meant by competition in the natural world?

Answer 5

• Plants in a community or habitat compete with each other for light, space, water and mineral ions
• Animals compete with each other for food, mates and territory

Question 6

What is interdependence?

Answer 6

Species depend on each other for food, shelter, pollination, seed dispersal etc., removing a species can affect the whole community

Question 7

What are abiotic factors?

Answer 7

Non-living factors that affect a community. These include:

• Living intensity
• Temperature
• Moisture levels
• Soil pH, mineral content
• Wind intensity and direction
• Carbon dioxide levels
• Oxygen levels for aquatic organisms

Question 8

What are biotic factors?

Answer 8

Living factors that affect a community. These include:

• Availability of food
• New predators arriving
• New pathogens
• One species outcompeting so numbers are no longer sufficient to breed

Question 9

What are the steps in the carbon cycle?

Answer 9

1) CO2, taken in during photosynthesis
2) Dead organisms decayed by bacteria and fungi releasing carbon
3) Organisms respire releasing CO2

Question 10

What are the steps in the water cycle?

Answer 10

1) Precipitation (rain)
2) Surface run-off
3) Evaporation from oceans, lakes and streams
4) Transpiration from plants
5) Condensation

Question 11

What are the different types of adaptations and give some examples

Answer 11

Adaptations can be structural, behavioural or functional. Examples include:

1) Cactus in dry desert - No leaves to reduce water loss, wide deep roots for absorbing water
2) Polar bear in cold arctic - Hollow hairs to trap layer of heat. Thick layer of fat for insulation
3) Deep sea bacteria - Populations form in thick layers to protect outer layers from extreme heat of vents

Question 12

What are food chains and what order do they go in?

Answer 12

Feeding relationships in a community. The order of a food chain is:

Producer —> Primary consumer —> Secondary consumer —> Tertiary consumer

• All food chains begin with a producer that is usually a plant
• Consumers that kill and eat other animals are predators and those eaten are prey
• In a stable community the numbers of predators and prey rise and fall in cycles

Question 13

What is biodiversity?

Answer 13

The variety of all different species of organisms on Earth, or within an ecosystem

Question 14

What are quadrats and transects?

Answer 14

• Organisms are counted within a randomly placed square
• Organisms are counted along a belt of the ecosystem

Question 15

What are trophic levels?

Answer 15

Trophic levels are numbered sequentially according to how far they are along the food chain.

Level 1: Producers - Plants and algae
Level 2: Herbivores - Primary consumers
Level 3: Carnivores - Secondary consumers
Level 4: Carnivores - Tertiary consumers

• Apex predators are carnivores with no predators

Question 16

What is the transfer of biomass?

Answer 16

• Biomass is lost between the different trophic levels
• Producers transfer about 1% of the incident energy from light for photosynthesis
• Decomposers break down dead plants and animal matter by secreting enzymes. Small soluble food molecules than diffuse into the microorganism
• Approximately 10% of the biomass from each trophic level is transferred to the level above
• Large amounts of glucose is used in respiration, some material engested as faeces or lost as waste

Question 17

What is global warming?

Answer 17

• Levels of CO2 and methane in the atmosphere are increasing
• Decreased land availability from sea level rise, temperature rise damages delicate habitats, extreme weather events harm populations of plants and animals
• There is a global consensus about global warming and climate change based on systematic reviews of thousands of peer reviewed publications

Question 18

Why is it important to maintain biodiversity?

Answer 18

1) Ensures the stability of ecosystems - By reducing dependence on one species on another for food, shelter, maintenance of the physical environment
2) Future of human species - Many human activities are reduce biodiversity and only recently measures have been taken to stop it

Question 19

What are some of the negative impacts of human activities on biodiversity?

Answer 19

1) Waste management - Rapid growth in human population and higher standard of living. This leads to:
- More resources being used and more waste being produced
- Pollution in water; sewage, fertiliser, toxic chemicals etc.
- Pollution in air; smoke or acidic gases
- Pollution on land; landfill and toxic chemicals

2) Land use - Humans reduce the amount of land and habitats available for other plants, animals and microorganisms. This includes:

• Building and quarrying
• Farming for animals and food crops
• Dumping waste
• Destruction of peat bogs to produce cheap compost for gardeners/farmers to increase food production

Question 20

Why is destroying peat bogs bad from the environment?

Answer 20

• The decay/burning of peat release CO2 into the atmosphere
• This conflicts with conserving peat bogs and peatlands as habitats for biodiversity and reduce CO2 emissions

Question 21

What are the impacts of large scale deforestation?

Answer 21

• Deforestation is where trees are cut down in tropical areas to provide land for cattle and rice fields, grow crops for biofuels
• It reduces biodiversity and removes a sink for increasing the amount of CO2 in the atmosphere

Question 22

What is the impact of environmental change?

Answer 22

Environmental changes affect the distribution of species. These changes can be seasonal, geographic or caused by human interaction. Examples include:

• Temperature
• Availability of water
• Composition of atmospheric gases

Question 23

What are some of the positive impacts of human activities on biodiversity?

Answer 23

• Scientists and concerned citizens put in place programs to reduce the negative impacts of humans on ecosystems and biodiversity
• Breeding programs for endangered species
• Protection and regeneration of rare habitats
• Reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
• Reduction of deforestation and CO2 emissions by some governments
• Recycling resources rather than dumping waste in landfill
• However, some of the programs potentially conflict with human needs for land use, food production and high living standards

Question 24

What are the factors that affect food security?

Answer 24

Enough food is needed to feed a changing population. Factors affecting food security are:

• Increasing birth rate
• Changing diets in developing countries
• New pests and pathogens affecting farming
• Environmental changes (eg. famine)
• Cost of agricultural input
• Conflicts affecting water/food availability

Question 25

Give some examples of types of food production and how they effect the environment

Answer 25

1) Farming techniques: increasing efficiency of food production - reduce energy waste, limiting movement, control temperature, high protein diet to increase growth
2) Sustainable fisheries: fish stocks in oceans are declining - maintain/grow fish stocks to a sustainable level where breeding continues or certain species may disappear. By controlling net size, fishing quotas however some people have concerns about the treatment of animals
3) Biotechnology: meeting the demands of a growing population. This includes:

• Fungus fusarium to produce mycoprotein. Requires glucose syrup, aerobic conditions. Biomass is harvested and purified
• GM bacterium produces insulin to treat diabetes
• GM crops to provide more/nutritional food (golden rice)