Biology 1b Flashcards
How has a polar bear evolved to stay warm ?
Thick layer if blubber for insulation
True or False - animals in the desert have a large surface area to volume ratio
True
What is another benefit of blubber ?
Acts as an energy store when food is scarce
How has the arctic fox evolved to avoid predators ?
Light fur to blend in with snow
Why do cacti have spines rather than leaves ?
- Plants lose water vapour from the surface of the leaves. Spines have a smaller surface area so less water is lost
- They deter predators as they are sharp
give two ways wasps deter predators
- Stinger
- Sting contains poisons
- Yellow and black coat signifies danger
What is an extremophile ?
A microorganism that can live in very extreme environments, like volcanic vents
What do plants compete for ?
Light
Space
Water
Minerals from soil
What do animals compete for ?
Space (territory)
Food
Water
Mates to reproduce with
What is a living factor ?
Disease
Predators
Prey or food sources
Competitors
What is a non-living factor ?
Temperature
Rainfall
Pollution - air or water
What is a living indicator of air pollution ?
Lichen
What is lichen an how does it show pollution ?
They are a moss like plant that grow on tree bark. Different species grow in different areas depending on the sulphur dioxide in the atmosphere.
What is a pollution indicator of water pollution ?
Mayfly lavae
How does mayfly larvae indicate water pollution ?
They are very sensitive to the concentration of dissolved oxygen in water - left by sewage. If you see mayfly larvae the water is clean
What is an example of a non-living indicator of environmental change ? How does it measure this ?
Satellites, it can measure snow and ice cover and sea temperature
What does a pyramid of biomass show ?
The mass of living material on each tropic level of a food chain
What is a tropic level ?
It is the word given for the different stages of the food chain
What is a producer ?
A plant
The energy gradually decreases as you go up a tropic level. Why does this happen ?
Each tropic level uses some of the energy for movement ( any of the 7 life processes )
What are the perfect conditions for microorganisms ?
Moist, warm conditions
How do you make the most of a compost bin ?
Finely shredded waste
Air holes
How is carbon dioxide released into the atmosphere ?
- Burning fossil fuels
- Plant/animal respiration
- CO2 released from decay
How is carbon dioxide removed from the atmosphere ?
Mainly photosynthesis
Some dissolves in sea
What is genetic variation ?
Your characteristic differences to others that is down to your genetic information
What is environmental variety ?
When you are different because of the environment. Like dying your hair or losing a limb
What is the nucleus ?
The part of a cell which holds your genetic material in chromosomes
What is a chromosome ?
Coils of DNA
What is DNA ?
DNA is the genetic material of humans, found in the nucleus of cells
What is sexual reproduction ?
It involves the fusion of male and female gametes. There are two parents so the offspring will contain a mixture of their parents’ genes
What is asexual reproduction ?
Only one parent, so no gamete fusion no mixing of DNA and therefore no genetic variation. Producing a clone of the parent
How do you clone plants from cuttings ?
You cut parts of the plant off and re-plant them making identical copies
How do you clone a plant by tissue cloning ?
When a few plant cells are put on hormones an quickly grow to be clones of the parent
How do you clone animals ?
An egg is taken from a prize cow and fertilised by a prize bull. The embryo is split and placed in other cows, when born you will have multiple clones
Explain adult cell cloning
- Adult cell cloning is when you take an unfertilised egg and taking the genetic information out of it.
- A males body cell’s DNA is then implanted in
- The now fertilised egg is implanted into a surrogate mother and a clone will be born
What is genetic engineering ?
It is when you can change the genes to alter the corresponding characteristics
How do scientists ‘cut’ parts of the genes out ?
They use enzymes
What is a GM crop ?
A genetically modified plant
What are the benefits if GM crops ?
Resistant to:
Insects
viruses
Herbicides (weed killer)
How do scientific milestones like genetic engineering help the human body ?
Cystic fibrosis is a disorder caused by faulty genes, by developing genetic engineering we may be able to eradicate it
What is the theory of evolution ?
The idea that more than 3 billion years ago life on earth began as simple organisms from which more complex organisms have evolved into
What is natural selection ?
- Individuals within a species have variety because of genetic differences
- If they have better characteristics then they will survive and reproduce
- Eventually only the new variation will survive
What, other than genetic variety, can cause natural selection
Mutation
Why did some not believe in Darwin’s theory ?
- Went against religious beliefs that life was created by god
- He couldn’t give a reason why these varieties occurred
- There wasn’t enough evidence
What was lamarck’s theory ?
He thought that if the characteristics were used a lot then they would develop and pass on to their offspring. For example if a rabbit ran a lot then its legs would get longer
Why was lamarck’s theory wrong ?
Because these changes weren’t involved with your DNA, therefore it wouldn’t pass on to offspring
What are genes ?
They develop different characteristics like eye colour
