all exam questions that i dont know Flashcards
what is the maximum number of X chromosomes found in the nucleus of a sperm cell
1
suggest the function of the acrosome
the acrosome’s function is to release enzymes that break down the membrane of the egg to allow for fertilisation.
describe the route taken by a sperm cell from when it enters a women’s body to the site of fertilisation of the egg
It travels up the vagina, through the cervix into the oviducts.
the fish they eat is initially crushed in part of their digestive system called the gizzard.
suggest why crushing the fish in the gizzard helps the birds to digest the fish.
1) increase surface area
2) enzymes
the scientist concludes that training improves the athletic performance. (capillaries question)
1) more capillaries to transport oxygen
2) more aerobic repsiration
3) more energy
4) more muscle contraction
5) less lactic acid
explain how natural selection could be responsible for the results shown in the graph between 0 and 100 metres.
1) more grass flourishes
2) less competition
3) mutation
4) reproduce
5) passes allele onto offspring
describe a method the scientist could use to compare the population size of the grass species at 50 metres and 100 metres from the mine
1) use tape measure
2) quadrat
3) repeat
4) count plants
give one reason why the student uses the same volume of water in each beaker
1) to prevent surface area affecting heat loss
2) fair test
the scientist concludes that it is better for farmers to keep their animals indoors.
Discuss this conclusion
1) less heat loss indoors
2) depends upon outside temperature
3) animals move around less
4) more energy for growth
5) diseases are easier to spread
describe how the student could modify his investigation to find out if an animal’s body size affects heat loss
1) use container of different sizes
2) keep beakers out of box
explain the advantage of a withdrawal reflex when a finger touches a hot object
1) fast
2) automatic
3) less damage
describe how the scientists could tell if a maize seed had germinated
if the shoot has grown
explain the effect of increasing the concentration of salt solution on germination
1) increasing salt concentration decreases germination
2) as concentration of the solution increases , lower water potential
3) less water absorbed
4) by osmosis
compare the responses of roots and stems to gravity
roots grow towards gravity meaning they are positively geotropic
compare the responses of roots and stems to light
1) roots grow away from light
2) negatively phototropic
suggest why spring and winter wheat have different percentages of insecticide applied to them
1) in winter there is a lower temp
2) fewer insects
3) less insecticide needed
explain an alternative to insecticide that a farmer could use
1) use biological control
2) use a predator to target pests
a person with sickle cell anaemia often suffers pain as some of their blood vessels become blocked by the sickle cells.
suggest why the person’s blood vessels may become blocked
sickle shaped red blood cells stick to eachother/caught trapped
people with sickle cell anaemia have symptoms of tiredness and joint pain that get worse if they are exposed to cold temperatures and high altitudes.
suggest why these symptoms get worse
1) cold temp reduces blood flow
2) less oxygen at high altitudes
3) less repsiration
4) more lactic acid
5) less energy
what is meant by the term recessive
no dominant allele present
what type of organism causes malaria
protoctist
give two differences in structure between red blood cells and white blood cells
1) red cells smaller
2) red cells have no nucleus
3) red cells are biconcave
explain the factors that affect the rate if movement of substances into and out of cells
1) temp increases kinetic energy/more collisions
2) concentration gradient increases rate of movement
3) shorter distances increase diffusion
4) surface area to volume ratio increases diffusion
5) size of smaller particles move faster
6) charged particles cannot pass through membrane
7) increased energy for actibve transport
describe the differences between
diffusion and active transport
1) diffusion is passive
2) diffusion from high to low concentration
3) active transport requires energy
4) active transport requires membrane
5) diffusion can take place in non-living systems
design an investigation to find out if changing the starch content of the flour causes the bread to expand more.
1) change amount of starch
2) use same species of yeast
3) repeat each flour type more than once
4) measure height using ruler
5) after stated time
6) use same measure of flour
7) same temperature
explain the function of the paddles in the fermenter
1) to distribute food/nutrients
2) to distribute oxygen
explain why the ph in the fermenter needs to be controlled
1) it needs to be suitable for enzymes
2) would prevent denaturation of enzymes
explain two changes that need to be made to the design of the fermenter so it can be used to produce biogas by anaerobic fermentation
1) stop air supply
2) open pressure release valve
describe the role of the air supply in the fermenter
to supply oxygen to the organism so they can repsire
suggest why the air filter is included in the fermenter
to prevent the entry of bacteria
explain what will happen to the growth of the microorganisms if temperature regulation fails
the temp will get too high and the enzymes will denature
what is meant by the term gentically modified transgenic organism?
An organism that contains genes from another species.
explain the benefits of cloning transgenic organisms
mroe genetically identical organisms produced
describe the process of making yoghurt from milk
1) pastureisation
2) kill bacteria
3) reduce temperature
4) add lactobacillicus
5) leave for a fixed amount of time
explain why people who are lactose intolerant are able to eat yoghurt without becoming ill
1) it contains no lactose
2) Therefore the lactose doesn’t need to be digested
suggest the benefits of adding fruit to sweeten yoghurt
1) it gives you fructose, natural sugar
2) provides vitamin c which prevents scurvy
name the carbohydrate stored in the cytoplasm of a yeast cell
glycogen
descirbe how the student makes sure that the yeast cells respire anaerobically
use oil
design an investiagtion to determine which variety of yeats is best for producing low alcohol beer.
1) use yeast A and B
2) same concentration of yeast
3) repeat
4) measure concentration of alcohol in beer
5) add same concentration of starch
6) control temperature
describe the stages that are used to gentically modify a bacterium that is able to manafacture human growth hormone
1) human gene
2) restriction enzyme
3) plasmid
4) vector
5) same restriction enzyme
6) ligase
7) recombinant plasmid
what is meant by the term hormone
something that travels in the blood stream to target cells.
describe how selective breeding could be used to increase milk production
1) cow with high milk yield
2) are allowed to reproduce
3) repeat the process with high milk yield offspring
descibe how a name bacterium produced this yoghurt from milk
1) lactobacillicus
2) lactose
3) lactic acid
