Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

34 Cards in this Set

  • Front
  • Back
  • 3rd side (hint)

What is evolution?

The gradual change in organisms when adapting to their environment

What is the theory of natural selection/survival of the fittest? (Darwin) (4 points)
1. There's a wide variation in species
2. Competition for limited resource and the best adapted survive
3. Those that survive reproduce
4. They pass on their successful adaptations to their offspring
What are three reasons for why people disagreed with Charles Darwin's theory?
1. It went against religious beliefs
2. Not enough evidence to show how organisms changed
3. No explanation for why the useful characteristics formed
What are two reasons for why Charles Darwin's theory is now accepted?
1. Discussed and test by wide range of scientists
2. Provides explanation for observations from scientists
What was Lamarck's theory for evolution?
If a characteristic was used a lot then it would be developed and passed on to offspring
Why was Lamarck's theory rejected?
There was no genetic basis
What is speciation?
Over a long period of time, natural selection can cause new species to be made
What causes speciation?
1. A physical barrier develop and splits a species. Eg river
2. The species are now in two different areas
3. Each area has different environments and so they develop different adaptations
4. Species become so different, they can no long breed to produce fertile offspring
5. Become reproductively isolated
What three things are the increase in the amount of pollution causing?
1. Global warming
2. Acid rain
3. Ozone depletion
What causes global warming?
When fossil fuels are burnt, lots of carbon dioxide is released which is a greenhouse gas, these trap heat in the atmosphere causing the global temp to rise
What three effects may occur if the global temperature continues to rise?
– Sea level rise
– Weather system become less predictable
– Agricultural output will fall
What causes acid rain?
Sulfur dioxide is release from burning of fossil fuels and waste material. This reacts with water in the atmosphere to form sulfuric acid which falls as acid rain
What three effects does acid rain have?
– Damages soils and kills trees
– Makes lakes acidic and many orgains are sensitive to pH changes and cannot survive
– Damages limestone (buildings and statues)
What causes ozone depletion?
The use of CFCs break down the ozone in the upper atmosphere
What effects does ozone depletion have?
More exposure to UV rays = skin cancer risk increased
Kill plankton in the sea = massive effect on sea ecosystem
What are indicator species?
Organisms which show whether an area is polluted or not
What two species survive in unpolluted conditions and what are they used to monitor?
Lichen = air quality
Mayflay larvae = water quality
What are three species that live in polluted water?
Water lice
Rat–tailed maggot
How do we use indicator species to measure pollution?
– Survey to see presence or absence of species
– Counting the number of times a species occurs gives a numerical value
How can pollution be measured directly, without indicator species? (Two methods)
–Using sensitive instruments to measure the concentrations of chemical pollutants
– Using satellite data to indicate pollutant level
What are three advantages of using indicator species to measure pollution?
– Quick
– Cheap
– Easy
What is a disadvantage of using indicator species to measure pollution?
Other factors like temperature may affect the survival of species = not always reliable
What are two advantages of using non–living methods to measure pollution?
– A reliable, numerical data is given which is easy to compare to other areas
– The exact pollutant can be identified
What is a disadvantage of using non–living methods to measure pollution?
Expensive = trained workers and specialised equipment
What does conservation mean?
Keeping everything the same
What is captive breeding?
Breeding species so there is less chance of extinction
What does endangered mean?
There is a low population of a species
What three factors cause extinction?
– Number of habitats: hard to find resources
– Number of individuals: hard to find mate
– Genetic variation: if low species is less likely to be able to adapt to changes in the environment or a disease
What four things can we evaluate conservation programmes on?
1. Genetic variation: to survive disease outbreak and environmental change
2. Viability of populations: able to reproduce
3. Available habitats: suitable habitats
4. Interaction between species: as they would in normal habitat eg. hunt prey
Give 3 ways that conservation programmes benefit humans

– Protects food supply: prevent over – fishing
– Medical research: plants in rainforest
– Cultural aspects: a species may be important to a nation eg. bald eagle in USA

How are conservation programmes benefitting to wildlife?
Minimal damage to food change (conserving one species, helps others to survive)
What does sustainable development mean?
Providing for the needs of todays population without harming the environment
Give 5 reasons for why whales are hunted

1. Tourism
2. Oil
3. Food
4. Cosmetics
5. Scientific research


If hunting of whales continues what three things will scientists not be able to find out?

1. Survival at extreme depths
2. Communication
3. Migration patterns