Flashcards in Waves, Specific heat capacity, Reactivity series, Acids and bases, Disease and Evolution Deck (30):
Describe natural selection...
Natural selection states that offspring will show variation in their characteristics and some variations will be better adapted to the environment than others. The limited resources will cause competition between individuals and those who have variations will be more likely to survive as they are better adapted and those who are not will die. Individuals that survive may breed and so many pass their variations on to their offspring.
What did Darwin realise which led to the theory of evolution?
Darwin realised that if the environment changes, the different variations may be better suited to the new competition. Also, he realised that the range of that range of variation in characteristics of the population will gradually change over generations, which i evolution.
According to Darwin's theory, what happens if the environment changes too rapidly?
No individuals have time to adapt (which will help them survive) and they will all die out and therefore the specie may become extinct.
Give an example of new evidence for Darwin's theory...
Warfarin is a chemical that was used to poison rates in the 1940s/50s and when it was first used most rats died from it. But within ten years most rats were resistant to warfarin, they had adapted in order to survive.
What are the 4 ways to neutralise an acid?
1. acid + base = salt + water
2. acid + metal = salt + hydrogen
3. acid + metaloxide = salt + water
4. acid + metal carbonate = salt + water + carbon dioxide
What is a compound?
More than one element together
What are bases? What are alkalis?
Bases are compounds that can neutralise acids, and alkalis are those bases that that are soluble in water, such as the hydroxides of group 1 metals.
What are the two similarities between transverse waves and longitudinal waves?
1. Can reflect.
2. Waves carry energy from place to place.
What are the three most reactive elements in the reactivity series?
Which non metal is ranked higher in the reactivity series, carbon or Hydrogen?
HCL+ Na0H =
Hydrochloric + Sodium
NaCL + H(small2)0
Sodium + water
2HCL + mg =
Hydrochloric + magnesium
MgCL(small 2) + H(small2)
Magnesium + Hydrogen
List the reactivity series...
What are the four pathogens that cause disease? Give examples of the diseases the cause...
1. Bacteria (cholera, food poisoning and TB)
2. Viruses (influenza, measles and AIDS)
3. Fungi (athlete's foot)
4. Protoctisits (malaria)
How is AIDS spread?
By body fluids (blood shared on syringe or during sexual intercourse)
H(small 2)SO(small4) + KO =
Sulphuric acid + Potassium oxide
KSO(small 4) + H(small 2) O
Potassium sulphate + water
H(small 2)NO(small3) + LiCO(small 3) =
Nitric acid + carbonate
LiNO(small 3) + H(small2)O + CO(small 2)
Lithium Nitrate + water + carbonate
How do transverse waves particles move?
Particles move at right angles to the direction the wave is moving.
What do longitudinal wave particles do?
The air particles are pushed together and move back and forth and have vibrations that are parallel to the direction of energy transfer.
An example of a longitudinal wave...
An example of a transverse wave...
What happens when water waves go from deep to shallow water?
The energy spreads itself out more and its speed slows down.
What is a genetic disease?
A disease which is caused by an abnormality in someone's DNA, which are passed on by Autosomal recessive inheritance.
What can white blood cells do?
Ingest pathogens (the cause of the disease and therefore destroy them)
Produce antibodies which neutralize pathogens such as bacteria and viruses.
Produce antitoxins that counteract the toxins released by pathogens.
What is made in the stomach to kill harmful bacteria?
What happens to the bacteria that can survive acid conditions in the stomach?
This bacteria can later be identified and killed with antibiotics.
What enzyme does blood, tears, mucus and saliva contain? What does it do?
Lysozyme. It breaks down cells walls of bacteria and destroys them.
How does the body defend itself when the skin is cut?
The blood begins to clot in order to prevent the entry of pathogens.
How do diseases spread:
through contact with animals,
through contaminated foods,
through touch (direct or indirect, like athlete's foot),