// Topic 2 Flashcards
when an eye changes from focusing on a distant object to focus on a near object…
A) the lens gets thinner to bend the light rays more
B) the lens gets thicker to bend the light rays more
C) the lens gets thinner to bend the light rays less
D) the lens gets thicker to bend the light rays more
B - the lens gets thicker to bend the light rays more
give a reason why people who are short sighted cannot see distant objects clearly
light rays meet in front of retina
state the type of lens that can be used to correct short sightedness
concave
a student was given the hypothesis that people with brown eyes are more likely to be short sighted than people with blue eyes
devise an experiment to test this hypothesis
choose equal numbers of people with brown and blue eyes. test their vision using a test to test their vision. then count the number of people in each group who are short sighted. if the conclusion is that people with brown eyes are more likely to be short sighted then hypothesis is correct
name the process as cells turn into root hair cells
differentiation
describe the advantages of producing plants by the method shown in figure 8 (agar growth)
many plants produced - quicker than sexual production
one of the plantlets had different coloured leaves. give one reason why this plant let had different coloured leaves
mutation - disease
in 2012 two scientists were awarded the nobel prize for their research on stem cells showing that adult cells could be programmed to become cells with the properties of embryonic stem cells.
describe the possible benefits of this research
have the potential to produce any cell type so there’s no need to use embryonic stem cells. this means there is less chance of the patient rejecting their own cells
which is the correct order for mitosis?
A) Q —> R —> S —> P
B) R —> Q —> S —> P
C) R —> S —> Q —> P
D) Q —> S —> R —> P
B) R —> Q —> S —> P
the stage of mitosis labelled in S in figure 11 is
A) anaphase
B) prophase
C) telophase
D) metaphase
A - anaphase
describe what happens during interphase
DNA is replicated and the production of cells proteins occur as well as metabolic activities occurring
the effect of age on focusing distance was investigated. when the words became out of focus of a book read the distance was recorded. figure 4 shows data
give one conclusion that can be made from the data in figure 4
as age increases focusing distance increases
the effect of age on focusing distance was investigated. when the words became out of focus of a book read the distance was recorded. figure 4 shows data
give two improvements that are needed in this investigation before a valid conclusion can be made
- use more ages
2. repeat the test for each person
which part of the eye detects coloured light?
A) iris
B) lens
C) cones
D) cornea
C) cones
describe how light rays are focused to given normal vision
light rays are bent at the cornea and light rays focus on the retina
figure 6 shows light rays entering a defected eye and two lenses tat can be used to correct eye defects (concave, convex)
explain which lens would correct the eye defect shown in figure 6
lens X which is a concave lens. lens X will spread out the light rays
name the part of the brain labelled
cerebral cortex
explain why myelination is needed on motor neurones but not on neurones in the brain
myelination speeds up impulses and insulates the axon. its needed on motor neurones because they transmit information over a greater distance
describe the role of sensory neurones
transmit electrical impulses from receptors to the brain
explain how impulses are transmitted at synapses
a synapse is a gap between neurones, and the electrical impulse stimulates the release of the chemical known as a transmitter. this diffuses across the gap
describe the function of a meristem in the growth of a plant
are undifferentiated and divide by mitosis to produce more cells
drink manufacturer wants to advertise the effect of the drink on reaction time but needs to confirm the effect on reaction time by improving the experiment
give two improvements the manufacturer would need to make to this investigation
- more repeats on same people
2. repeat the experiment with just water
name the type of neurone shown in figure 10
sensory neurone
which row identifies structure p and q?
A) myelin sheath, axon
B) cell body, dendron
C) myelin sheath, dendron
D) cell body, axon
B) cell body, dendron
some painkillers prevent neurotransmitters binding to receptors in a synapse. explain how a signal is transmitted at a synapse and how the painkillers reduce the pain felt by the person
neurones transmit electrical impulses and the synapse is the gap between two neurones. this triggers the release of neurotransmitters which diffuse across the synapse as a chemical signal. neurotransmitters bind to receptor cells on next neurone triggering an electrical impulse in the next neurone. the painkiller prevents neurotransmitters from binding to receptors in next neurone and as a result the electrical impulse isn’t triggered and the signal not received by central nervous system (CNS). this means the person doesnt feel pain
cell division occurs during the cell cycle. during which stage of the cell cycle is DNA replicated?
A) anaphase
B) prophase
C) interphase
D) telophase
C) interphase
