Past Paper Flashcards
Suggest TWO reasons why people should stop smoking
Smoking can cause cancers such as lung cancer
Cigarettes decrease life expectancy
Why do people find it difficult to stop smoking?
Cigarettes include nicotine which is addictive
What word is used to describe the differences between members so the same species?
Variation
Adders whose colour is all black, for example, are seen occasionally.
What word is used to describe the sudden change in colour?
What chemical is altered to cause this change in colour?
Mutation
DNA
State ONE way the offspring produced by sexual reproduction differ from those produced by asexual reproduction.
Sexual reproduction involves two organisms whereas asexual involves only one organism that splits into two and therefore, have different genes and chromosomes
When body temperature rises, how does a sweat gland help to lower it?
When the body temperature rises, the sweat evaporates and it transfers heat from your skin to the environment, cooling you down.
If the results were recorded, describe how, after eating a meal, a pre-diabetic man’s resulted would differ from a normal mans results.
A normal man’s glucose level would only go up slightly whereas the prediabetic man’s would rise a lot. The rise and fall would be more rapid.
The prediabetic glucose level in his blood would drop below the normal man.
The glucose in the prediabetic man’s blood would take longer to get back to normal or level off.
How could a diabetic man avoid the high rise in blood glucose that could occur after eating?
He could inject himself with insulin before his meal.
What happens in the body of a normal man to reduce the blood glucose level after a couple of hours after eating a meal?
Insulin is released into the mans bloodstream where it converts glucose into glycogen, which is stored in the liver.
Rabbits - allele for black fur is B (dominant)
- allele for white fur is b
A rabbit breeder bought a rabbit with black fur but didn’t know if it was homozygous or heterozygous. She used a white rabbit to find out the genotype of the rabbit that was bought.
Cross 1 - if the black rabbit is BB
Cross 2 - if the black rabbit is Bb
Look in pictures.
Relating to the rabbit question, explain how the results shown in the Punnett squares determine whether the bought rabbit was homozygous or heterozygous.
If the bought rabbit was homozygous or BB the all of the offspring would be black.
If the bought rabbit was heterozygous or Bb, then 50% of the offspring would be black.
The bought rabbit must be Bb to produce any white rabbits.
Biologists compared a chemical from a newly found species of slug with the same chemical of other types of slug or see if they we’re closely related.
Name the chemical that was compared.
DNA
(Relating to the slug question)
From which structures found in the nucleus of cells was the chemical taken?
Chromosomes / genes
Give ONE reason why scientists use scientific rather than common names for organisms.
Scientific names are used by all.
Check page 7 of the booklet
How well did she know it?
Give ONE reason why some people might object to research involving mice.
Unethical to experiment on animals.
Explain, in terms of natural selection, the change in brain size during the evolution of Homo sapiens.
They mutated which lead to variation.
A large brain is essential to survival value. Genes / alleles passed on.
Why were the ideas of Charles Darwin concerning human evolution not accepted by many people in the 19th century?
Most people believed in creationism and went against religious views.
Describe the path taken by a nerve impulse during a withdrawal reflex when a hand touches a hot object.
The receptor detects a stimulus or change in environment and the sensory neurone sends a signal to the relay neurone. The motor neurone sends a signal to the effector, which produces a response.
Cats: Allele for short hair - D (dominant) Allele for long hair - d The short haired cat was mated with a long harried cat. All the offspring had short hair. Complete the following to show the genotypes of the parents. 1. The cat with short hair 2. The cat with long hair
- DD
2. dd
In 1982, the same species of pine tree was planted on both sides of a river valley. In 2011 the trees were surveyed at 3 different points;
A - north facing slope
B - beside the river
C - south facing slope
The average height of the trees were recorded;
A - 8.6m
B - 11.4m
C - 10.7m
1) what is the term used to describe the differences found between members of the same species?
2) suggest TWO environmental reasons for the differences in the average height of the trees growing at survey points A and B.
3) all the trees growing at survey point C were growing under exactly the same environmental conditions, but the difference in height between the individual trees was as much as 0.5m. Suggest a reason for this difference.
1) variation
2) i. ‘A’ have less water than ‘B’ as they are further away from the river.
ii. ‘A’ have less sunlight than ‘B’ as the south facing slope has more sunlight.
3) they are genetically different.
Explain in detail the role the sweat gland plays in lowering body temperature in warm conditions.
Sweat is produced by removing water and salts from the blood.
Sweat travels up the sweat duct, through the sweat pore onto the surface of the skin.
The water in the sweat then evaporates, removing the heat from the body.
The energy in 100g of white sliced bread is 992kJ and the GDA for an adult is 8400. Calculate the mass of the bread which an adult needs to eat to reach their GDA of energy.
8400 divided by 992 x 100
=846
If a test was done to try and find out the energy content of bread by burning it, why would be a reason you would not get an accurate result?
Most of the heat produced will be lost to the surroundings.
John grew some seedlings in a laboratory. When the shoots were long enough, he placed a lamp on one side of where the plant was growing. After 48 hours John examined the shoots.
1) State how their appearance had changed.
2) State the name of the response shown by the shoots of the seedlings.
3) Name the group of chemicals that controls this type of response.
1) The shoots would have grown or curved towards the light from the lamp.
2) Positive phototropism
3) Hormones
John did the same experiment but put the seedlings on a rotating plate.
1) Were the shoots growing; away from the light, towards the light or straight up?
2) Explain why you chose the answer.
1) Straight up
2) All sides of the shoot received an equal amount of light because the shoots are revolving.
