PAPER 2 REVISION Includes work on the following sections: B5 - Homeostasis and Response B6 - Inheritance, Variation and Evolution B7 - Ecology ...
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PAPER 2 REVISION
Includes work on the following sections:
B5 – Homeostasis and Response
B6 – Inheritance, Variation and Evolution
B7 - Ecology
B5 content – Homeostasis and Response (Paper 2) ❑ Homeostasis and Body Temperature ❑ The Nervous System, The Brain and The Eye ❑Hormones (endocrine system, blood glucose, water balance) ❑Reproduction (sex hormones, menstrual cycle, reducing fertility, increasing fertility[HT]) ❑Plant hormones (functions of plant hormones, uses of plant hormones[HT]) Required practicals: – Reaction time (page 48 in revision guide) – The effect of light and gravity on cress seeds (page 55 in revision guide)
Make notes for Homeostasis and Body
Temperature (P. 46 – 47)
• The importance of homeostasis
• Control systems
• Control of body temperature
Homeostasis and body temperature exam style question
Q1.
A scientist measured the volume of sweat lost between 9.00 am and 2.59 pm in one day
by one person. The graph below shows the results. (iii) Suggest one way the person could replace the water that was lost as sweat.
______________________________________________________________
______________________________________________________________
(1)
(b) (i) Sweating helps keep our internal body temperature within a narrow range.
Which organ monitors body temperature?
Tick (✔) one box.
brain
kidney
pancreas
(1)
(ii) The organ that monitors internal body temperature receives information about
temperature from the skin.
Which structures in the skin send impulses with this information?
Tick (✔) one box.
(a) (i) Suggest what happened at 11.00 am.
capillaries
Tick (✔) one box.
The person moved into a cold
glands
room.
The person removed their
receptors
coat.
(1)
The person started running a
race.
(c) How does sweating help to control body temperature?
(1)
___________________________________________________________________
(ii) Calculate the total volume of sweat lost between 11.00 am and 1.59 pm.
___________________________________________________________________
______________________________________________________________ (1)
(Total 6 marks)
______________________________________________________________
Total volume of sweat lost = _________ cm3
(1)
Make notes for the nervous system and
the eye (P. 48 – 49)
• The nervous system
• The brain
• The eye
The nervous system and the eye exam style question
Q2.
(e) Figure 2 shows some structures involved in the coordination of a reflex action.
Many human actions are reflexes.
(a) Which two of the following are examples of reflex actions? Figure 2
Tick two boxes.
Jumping in the air to catch a ball
Raising a hand to protect the eyes in bright light
Releasing saliva when food enters the mouth
Running away from danger
Describe how the structures shown in Figure 2 help to coordinate a reflex action.
Withdrawing the hand from a sharp object ___________________________________________________________________
(2) ___________________________________________________________________
Figure 1 shows how the size of the pupil of the human eye can change by reflex action.
___________________________________________________________________
Figure 1
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(b) Name one stimulus that would cause the pupil to change in size from A to B, as
shown in Figure 1. ___________________________________________________________________
____________________________________ ___________________________________________________________________
(1)
___________________________________________________________________
(c) Structure Q causes the change in size of the pupil.
___________________________________________________________________
Name structure Q.
___________________________________________________________________
____________________________________
(1)
___________________________________________________________________
(d) Describe how structure Q causes the change in the size of the pupil from A to B.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________ (6)
(1) (Total 11 marks)
Make notes for hormones (P. 50 – 51) • The endocrine system • Control of blood glucose • Water balance
Hormones exam style question
Q3. How is the recommended diet of a person with diabetes different from the diet of a
Diabetes is a disease in which blood glucose (sugar) concentration may rise more than person without diabetes?
normal.
Use information from the charts.
(a) Which organ in the body monitors this rise in blood sugar?
Tick ( ) two box.
Draw a ring around your answer.
liver pancreas stomach The diabetic should get more energy from fat.
(1)
(b) One way of treating diabetes is by careful attention to diet.
The diabetic should get more energy from protein.
Chart 1 shows the recommended diet for a person with diabetes.
Chart 2 shows a diet for a person without diabetes. The diabetic should get less energy from carbohydrate.
The diabetic should get less energy from protein.
(2)
(c) Other than diet, give one way in which diabetes may be treated.
___________________________________________________________________
___________________________________________________________________Make notes for hormones and reproduction
(P. 52 – 53)
• The sex hormones
• Control of the menstrual cycle
• Reducing fertility
• Increasing fertilityReproduction exam style question
Q4.
(c) Complete the sentence.
The menstrual cycle in a woman is controlled by hormones.
In the menstrual cycle, one egg is released approximately every ____________
The diagram shows some of the glands in a woman’s body that produce hormones. days.
(1)
(d) Which hormone is used in the oral contraceptive pill?
Tick one box.
Adrenaline
Insulin
Progesterone
Testosterone
(1)
(e) Describe how the oral contraceptive pill stops a woman becoming pregnant.
___________________________________________________________________
___________________________________________________________________
The hormones that control the menstrual cycle are produced by the pituitary gland and by ___________________________________________________________________
the ovaries.
___________________________________________________________________
(a) Which gland is the pituitary gland? (2)
Tick one box. (f) Complete the sentences.
Choose the answers from the box.
A B C D E
(1)
(b) Which gland is the ovary?
Tick one box. Development of the female secondary sex characteristics is controlled
by ____________________________ .
A B C D E
Sperm production is stimulated by ____________________________ .
(1) (2)
(Total 8 marks)Make notes for plant hormones (P. 54 –
55)
• Functions of plant hormones
• Uses of plant hormonesPlant hormones exam style question
Q5.
(b) After the plant had grown, the student put the plant pot by a window with lots of light.
A student investigated growth in plants.
The illustration below shows this.
The student:
• planted a seed in damp soil in a plant pot
• put the plant pot in a dark cupboard.
The image below shows the result after 5 days.
(i) Complete the diagram below to show the appearance of the student’s plant
after 20 days by the window.
(a) Draw a ring around the correct answer to complete each sentence.
away from water. (1)
(i) After the 5 days, the root had grown in the direction of the force of gravity. (ii) Explain the advantage to the plant of growing in the way that you have drawn
towards light. in part (b)(i).
(1) ______________________________________________________________
against the force of gravity. ______________________________________________________________
(ii) After the 5 days, the shoot had grown away from light.
______________________________________________________________
towards water.
(1)
______________________________________________________________
(2)
(Total 5 marks)B5 Required Practical Notes – Reaction time (page 48 in revision guide) – The effect of light and gravity on cress seeds (page 55 in revision guide)
Required practical exam style question
Q6.
Two students investigated reflex action times. (a) Suggest two ways the students could improve the method to make sure the test
would give valid results.
This is the method used. 1. _________________________________________________________________
1. Student A sits with her elbow resting on the edge of a table. ___________________________________________________________________
2. Student B holds a ruler with the bottom of the ruler level with the thumb of Student 2. _________________________________________________________________
A.
___________________________________________________________________
3. Student B drops the ruler. (2)
4. Student A catches the ruler and records the distance, as shown in the diagram (b) The table below shows Student A’s results.
below.
Distance ruler
Test Number
5. Steps 1 to 4 were then repeated. dropped in mm
1 117
2 120
3 115
4 106
5 123
6 125
7 106
What is the median result?
Tick one box.
106
115
116
117
123
(1)Required practical exam style question
continued
(c) The mean distance the ruler was dropped is 116 mm. (e) A woman has a head injury.
Calculate the mean reaction time. Her symptoms include:
Use the equation: • finding it difficult to name familiar objects
• not being able to remember recent events.
reaction time in s = Suggest which part of her brain has been damaged.
Give your answer to 3 significant figures ___________________________________________________________________
(1)
___________________________________________________________________
___________________________________________________________________ (f) A man has a head injury.
___________________________________________________________________ He staggers and sways as he walks.
Mean reaction time = ______________________ s Suggest which part of his brain has been damaged.
(3)
___________________________________________________________________
(d) The students then measured Student A’s reaction time using a computer program. (1)
(Total 10 marks)
This is the method used.
1. The computer shows a red box at the start.
2. As soon as the box turns green the student has to press a key on the
keyboard as fast as possible.
3. The test is repeated five times and a mean reaction time is displayed.
Student A’s mean reaction time was 110 ms.
Using a computer program to measure reaction times is likely to be more valid than
the method using a dropped ruler.
Give two reasons why.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________
(2)B5 Revision – Homeostasis and Response (page 46-55 in revision guide)
Name three things that must be What happens to pupil size in dim Fill in the missing eye diagram labels:
controlled by the body: light and why?
1.
2.
3.
What does the body do when we
get too hot?
Why do we need reflexes?
What does the body do when we
get too cold?
How can we map the brain?
Complete the table below on the different types of
diabetes:
What are the three main regions Why is the pituitary gland often Diabetes Cause Treatment
of the brain? called the master gland?
• Type 1
•
• List 2 advantages of kidney
dialysis: Type 2
1.
Why is contraception used?
2.
KEY WORDS: Retina
Homeostasis Iris
Receptor Negative
How many days in length is the
Where does auxin build up in a Reflex action Feedback
average menstrual cycle?
plant shoot? Synapse Vasodilation
Cerebellum Vasoconstriction
Cerebral cortex Insulin
Medulla Donor
MRI DialysisB6 content – Inheritance, Variation and Evolution
(Paper 2)
❑ Sexual and asexual reproduction (asexual,
sexual and meiosis)
❑DNA and Protein Synthesis (genome,
structure of DNA, making proteins,
mutations[HT])
❑Patterns of inheritance (Gregor Mendel,
modern ideas, genetic crosses, genetic
disorders, sex determination)
❑Variation and Evolution
❑Manipulating Genes (selective breeding,
genetic engineering, cloning)
❑Classification (classification, extinction,
evolutionary trees, speciation)Make notes for sexual and asexual
reproduction (P. 74 – 75)
• Asexual reproduction
• Sexual reproduction and meiosis
• Asexual versus sexual reproductionAsexual reproduction exam style question
Q1.
(a) Use words from the list to complete the sentences.
(c) When the foal grows up it will look similar to its parents but it will not be identical to
alleles chromosomes gametes genes mutations either parent.
The nucleus of a cell contains thread-like structures called __________________ . (i) Explain why it will look similar to its parents.
The characteristics of a person are controlled by __________________ ______________________________________________________________
which may exist in different forms called __________________ . ______________________________________________________________
(3) (1)
(b) The drawing shows some of the stages of reproduction in horses. (ii) Explain why it will not be identical to either of its parents.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(Total 8 marks)
(i) Name this type of reproduction ___________________________________
(1)
(ii) Name the type of cell labelled A __________________________________
(1)Make notes for DNA and protein synthesis
(P. 76 – 77)
• The genome
• The structure of DNA
• Making proteinsDNA and protein synthesis exam style question
Q2.
(d) Mutations of DNA cause some inherited disorders.
Our understanding of genetics and inheritance has improved due to the work of many
scientists. One inherited disorder is cystic fibrosis (CF).
(a) Draw one line from each scientist to the description of their significant work.
A recessive allele causes CF.
Scientist Description of significant work Complete the genetic diagram in Figure 2.
Carried out breeding experiments
on pea plants.
• Identify any children with CF.
• Give the probability of any children having CF.
Charles Darwin
Each parent does not have CF.
Wrote 'On the origin of species'.
The following symbols have been used:
Alfred Russel
Wallance D = dominant allele for not having CF
Worked on plant defence systems. d = recessive allele for having CF
Gregor Mendel Figure 2
Worked on warning colouration in
animals.
(3)
(b) In the mid-20th century the structure of DNA was discovered.
What is a section of DNA which codes for one specific protein called?
___________________________________________________________________
(1) Probability of a child with CF = _____________________
(3)
(c) Figure 1 shows one strand of DNA.
(e) What is the genotype of the mother shown in Figure 2?
The strand has a sequence of bases (A, C, G and T).
Figure 1 Tick one box.
Heterozygous
How many amino acids does the strand of DNA in Figure 1 code for?
Homozygous dominant
Tick one box.
Homozygous recessive
2
(1)
3 (Total 9 marks)
4Make notes for patterns of inheritance (P.
78 – 79)
• Gregor Mendel
• Modern ideas about genetics
• Genetic crosses
• Genetic disorders
• Sex determinationPatterns of inheritance exam style question
Q3. The diagram shows a representative sample of seeds produced by second generation
In the 1850s, Gregor Mendel carried out breeding experiments using peas. plants.
(a) The importance of Mendel’s work was not recognised until the early 1900s.
Explain why.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(i) Describe how the student could obtain a sample that is representative of
___________________________________________________________________ seeds produced by the second generation.
(2)
______________________________________________________________
(b) A student repeated one of Mendel’s experiments.
______________________________________________________________
The flow chart shows her procedure. (1)
(ii) What was the approximate ratio of yellow seeds to green seeds in the seeds
produced by the second generation?
______________________________________________________________
(1)
(iii) Seed colour in peas is controlled by a single gene which has two alleles.
Use a genetic diagram to show why this ratio of yellow seeds to green seeds
was produced by the second generation.
Use the symbol A to represent the dominant allele, and a to represent the
recessive allele.
(4)
(Total 8 marks)Make notes for Variation and Evolution (P.
80 – 81)
• Variation
• Natural selection
• Evidence for evolutionVariation and evolution exam style question
Q4.
The image below shows: (ii) Lamarck’s theory is different from Darwin’s theory.
• Phiomia, an ancestor of elephants
Use Lamarck’s theory to explain how the elephant’s trunk evolved.
• a modern African elephant.
______________________________________________________________
Phiomia lived about 35 million years ago.
______________________________________________________________
Phiomia African elephant
______________________________________________________________
______________________________________________________________
(2)
(b) (i) In the 1800s, many scientists could not decide whether Lamarck’s theory or
Darwin’s theory was the right one.
Give two reasons why.
© Dorling Kindersley via Thinkstock 1. ____________________________________________________________
Both Phiomia and the African elephant reach up into trees to get leaves. ______________________________________________________________
In the 1800s, Darwin and Lamarck had different theories about how the long nose of 2. ____________________________________________________________
Phiomia evolved into the trunk of the African elephant.
______________________________________________________________
(a) (i) Use Darwin’s theory of natural selection to explain how the elephant’s trunk
(2)
evolved.
______________________________________________________________ (ii) Before the 1800s, many people had a different idea to explain where all the
living things on Earth came from.
______________________________________________________________
What idea was this?
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________ (1)
(Total 9 marks)
______________________________________________________________
______________________________________________________________
______________________________________________________________
(4)Make notes for manipulating genes (P. 82 –
83)
• Selective breeding
• Genetic engineering
• CloningManipulating genes exam style question
Q5.
Many different types of animals are produced using selective breeding.
Some cats are selectively bred so that they do not cause allergies in people.
(a) Suggest two other reasons why people might selectively breed cats.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________
(2)
(b) Selective breeding could cause problems of inbreeding in cats.
Describe one problem inbreeding causes.
___________________________________________________________________
(1)
(c) Many people have breathing problems because they are allergic to cats.
The allergy is caused by a chemical called Fel D1.
Different cats produce different amounts of Fel D1.
A cat has been bred so that it does not produce Fel D1.
The cat does not cause an allergic reaction.
Explain how the cat has been produced using selective breeding.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(4)
(Total 7 marks)Make notes for classification (P. 84 – 85) • Principles of classification • Extinction • Evolutionary trees • Speciation
Classification exam Lemurs are only found on the island of Madagascar.
style question
Madagascar is off the coast of Africa.
Scientists think that ancestors of modern lemurs evolved in Africa and reached
Madagascar about 50-60 million years ago.
Today there are many species of lemur living on Madagascar.
Figure 2 shows information about water currents.
Q6.
Figure 3 shows the distribution of three species of lemur on Madagascar.
Figure 1 shows a ring-tailed lemur.
Figure 1 Figure 2 Figure 3
The table below shows part of the classification of the ring-tailed lemur.
Classification
Name
group
Kingdom Animalia
Phylum Chordata (c) Suggest how ancestors of modern lemurs reached Madagascar.
Mammalia ___________________________________________________________________
Primates
___________________________________________________________________
Lemuroidea (1)
Genus Lemur
(d) Describe how the ancestors of modern lemurs may have evolved into the species
catta shown in Figure 3.
(a) Complete the table above to give the names of the missing classification groups. ___________________________________________________________________
(2)
___________________________________________________________________
(b) Give the binomial name of the ring-tailed lemur.
___________________________________________________________________
Use information from the table above.
___________________________________________________________________
___________________________________________________________________
(1)
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________B6 – Inheritance, Variation and Evolution (page 74-85 in revision guide)
List two
characteristics that Complete the missing boxes: (Words: gene, nucleus).
are inherited:
1.
2.
What was Lamarck’s
theory, and why was he
wrong?
Complete the table below:
Why didn’t people Meiosis Mitosis
Label the oldest fossil layer. initially believe
Darwin’s theory of Sexual or
Label the newest fossil layer. evolution by Natural
selection?
asexual?
What can we learn from fossils?
No. of
divisions
Parents Cc x cc
No. of
Complete the Punnett square and identify
the probability of their child being normal,
daughter
a carrier or having Cystic Fibrosis. cells
Give two problems that
C c CC (normal) = %
can occur with
inbreeding animals.
KEY WORDS: Punnett square Fossil
c Cc (carrier) = %
Fossils
Extinction
Mendel
Environmental
Sediment
1. Layer
Allele Inherited
c Carrier Lamarck
Fossil record
Selective breeding
cc (affected) = % Dominant Darwin Genetic
2.
Recessive Natural selection Engineering
Variation Evolution HybridB7 content – Ecology (Paper 2) ❑ Ecosystems (relationships between organisms, adaptations, stable ecosystems) ❑Cycles and Feeding relationships ❑Disrupting Ecosystems (biodiversity, pollution, overexploitation, conserving biodiversity) ❑Feeding the World (need for more food, manipulating energy flow, biotechnology) Required practicals: – Investigating the population size of a common species in a habitat (page 87 in revision guide) – Investigating the decay of milk (page 88 in revision guide)
Make notes for ecosystems (P. 86 – 87) • Relationships between organisms • Adaptations • Studying ecosystems
Ecosystems exam style question
Q1.
Living organisms are classified into the following groups: The stone plant, Lithops bromfieldi, is adapted to live in very dry deserts.
• Kingdom Figure 1 shows several stone plants.
• Phylum
• Class
• Order
• Family
• Genus
• Species
(a) Which scientist first suggested this type of classification system?
Tick one box.
Alfred Russel Wallace
Carl Linnaeus
(b) Give the genus to which the stone plant belongs.
Charles Darwin ____________________________
(1)
Gregor Mendel
(1)Ecosystems exam style The jerboa is a small desert animal.
question continued
Figure 2 shows a jerboa.
(c) The stone plant has many adaptations that help it to survive in the desert.
Draw one line from each adaptation to how the adaptation helps the stone plant to
survive.
The jerboa is adapted for survival in the desert.
The jerboa spends the daytime in its underground burrow.
The jerboa only leaves its burrow to look for food during the night.
(d) Describe how these adaptations help the jerboa to survive in the desert.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(4)
(e) What type of adaptations are described in Question (d)?
Tick one box.
Behavioural
Functional
Structural
(1)
(Total 9 marks)Make notes for cycles and feeding
relationships (P. 88 – 89)
• Decomposition
• Recycling materials
• Feeding relationshipsCycles and feeding relationships exam style
question
Q2. (b) Name one type of living thing that causes decay.
A gardener investigates if turning over the waste in a compost heap makes the waste
decay more quickly. ___________________________________________________________________
(1)
The gardener:
• makes two separate heaps of garden waste, heap A and heap B (c) The gardener’s results are shown in the table.
• turns over the material in heap A every 2 weeks
Compost Estimated amount of
heap decay
• does not turn over the material in heap B
• estimates the amount of decay in the two heaps after 6 months. A A lot
The diagram shows the two heaps of garden waste at the beginning of the investigation.
B Very little
(i) Why does turning over the material in heap A make the material decay more
quickly?
______________________________________________________________
(a) Suggest two factors, other than time, the gardener should control to make the ______________________________________________________________
investigation fair. (1)
1. _________________________________________________________________ (ii) The gardener puts decayed material around his plants to help them grow.
___________________________________________________________________ Suggest why the plants in a woodland grow well each year without material
from compost heaps being added.
2. _________________________________________________________________
______________________________________________________________
___________________________________________________________________
(2) ______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(Total 6 marks)Make notes for Disrupting ecosystems (P.
90 – 91)
• Biodiversity
• Pollution
• Overexploitation
• Conserving biodiversityDisrupting (b) Another way to make sure there is food for an increasing human population is to
ecosystems exam
make food production more efficient.
Figure 2 shows how some cows are farmed.
style question
Q3.
It is important to conserve fish stocks.
Figure 1 shows a new type of fishing net and a traditional fishing net.
© Dageldog/iStock
(i) Use information from Figure 2 to suggest two ways in which this type of
farming reduces energy loss from the cows.
1. ____________________________________________________________
______________________________________________________________
(a) (i) Describe how the new type of fishing net helps to conserve fish stocks.
______________________________________________________________ 2. ____________________________________________________________
______________________________________________________________ ______________________________________________________________
(2)
______________________________________________________________
(ii) Give two reasons why some people disagree with farming cows in this way.
______________________________________________________________
1. ____________________________________________________________
______________________________________________________________
(3) ______________________________________________________________
(ii) Give one way, other than controlling nets, to reduce overfishing. 2. ____________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________ (2)
(1) (Total 8 marks)Make notes for feeding the world (P. 92 –
93)
• The need for more food
• Manipulating energy flow
• BiotechnologyFeeding the world (i) Suggest one reason why so much more energy is used per person in the USA
than in Bangladesh.
exam style question
______________________________________________________________
______________________________________________________________
(1)
(ii) Using a lot of resources for energy harms the Earth.
Q4. Explain why.
Improving the quality of life for everyone without damaging the planet for the future is
______________________________________________________________
known as sustainable development.
One problem is the rapid growth in the Earth’s population of humans during the last 500
years. This is shown by the graph. ______________________________________________________________
______________________________________________________________
(2)
(c) As we are using more resources, waste management is becoming more important.
In the UK much of the solid waste is still being dumped in landfill sites. In 1996, the
UK government introduced a landfill tax because landfill sites were being used up.
However, the year after the landfill tax was introduced it was estimated that 18
million tonnes of landfill waste was not reported. The government was trying to
encourage other forms of waste management, such as:
• reduce waste
• reuse waste
• recycle waste
(a) When the Earth’s population was much smaller, the effects of human activities on
forests were usually small and local. (i) Explain the main problem caused by the landfill tax.
In the past 500 years there has been large-scale deforestation in some areas. Give
two reasons for this. ______________________________________________________________
1. _________________________________________________________________ ______________________________________________________________
2. _________________________________________________________________ ______________________________________________________________
(2) (2)
(b) Look at the bar chart. It shows the average amount of energy used by each person (ii) Describe one example of how each of the different forms of waste
in one year in the USA, Japan and Bangladesh. management can be put into practice.
Reduce waste __________________________________________________
______________________________________________________________
Reduce waste __________________________________________________
______________________________________________________________
Reduce waste __________________________________________________
______________________________________________________________
(3)
(Total 10 marks)B7 Required Practical Notes – Investigating the population size of a common species in a habitat (page 87 in revision guide) – Investigating the decay of milk (page 88 in revision guide)
Required practical (c) How could the student improve the investigation so that a valid estimate can be
made?
exam style question
Tick two boxes.
Weigh the clover plants
Compare their results with another student’s
results
Q5.
A student was asked to estimate how many clover plants there are in the school field.
Count the leaves of the clover plants
The image below shows the equipment used.
Place more quadrats
Place the quadrats in a line across the field
(2)
(d) The table below shows the student’s results.
Number of
Quadrat
clover plants
number
This is the method used. counted
1. Throw a quadrat over your shoulder. 1 11
2. Count the number of clover plants inside the quadrat. 2 8
3. Repeat step 1 and step 2 four more times. 3 11
4. Estimate the number of clover plants in the whole field. 4 9
(a) What is the tape in the image above used for in this investigation? 5 1
___________________________________________________________________ Total 40
___________________________________________________________________ The area of the school field was 500 m2.
(1)
The quadrat used in the table above had an area of 0.25 m2.
(b) The teacher told the student that throwing the quadrat over his shoulder was not
random. Calculate the estimated number of clover plants in the school field.
The method could be improved to make sure the quadrats were placed randomly.
___________________________________________________________________
Suggest one change the student could make to ensure the quadrats were placed
randomly. ___________________________________________________________________
___________________________________________________________________ ___________________________________________________________________
___________________________________________________________________ Estimated number of clover plants = _________________
(1) (3)Required practical exam style question
continued
(e) What was the mode for the results in the table above?
Tick one box.
1
8
11
40
(1)
(f) Suggest which quadrat could have been placed under the shade of a large tree.
Give one reason for your answer.
Quadrat number ___________________
Reason ____________________________________________________________
___________________________________________________________________
(1)
(Total 9 marks)B7 – Ecology (page 86-93 in revision guide)
What is an ecosystem? Label the adaptations that a cactus has to help it survive
Draw the pyramid of biomass for this in its environment:
food chain next to it:
Pyramid of biomass
List 3 abiotic factors:
1.
2.
3.
What is a stable
community?
Give an example of an extremophile and where it lives.
What can we use to
estimate population
sizes of plants?
What is precipitation?
Give two ways that carbon is put back into the
List one advantage and atmosphere:
one disadvantage of
battery farming: 1.
2.
Advantage:
KEY WORDS:
Biodiversity Abiotic Carbon
Why are predator cycles out of phase Community Biotic Water
with prey cycles? Ecosystem Apex predator Decay
Disadvantage: Habitat Biomass Global warming
Population Quadrat Precipitation
Predator Adaptation Deforestation
Prey Extremophile Fishing quota
Relationship Sustainable MycoproteinB5 Answers/Mark scheme
Mark schemes
(e) Level 2: Scientifically relevant facts, events or processes are identified and
Q1. given in detail to form an accurate account.
4−6
(a) (i) The person started running a race.
1
Level 1: Facts, events or processes are identified and simply stated but their
(ii) 2300 relevance is not clear.
1 1−3
(iii) drinking (water / sports drink) No relevant content
0
or
through eating
1 Indicative content
(b) (i) brain • receptor detects stimulus
1 • e.g. receptor detects pressure
• receptor generates impulses / electrical signals
(ii) receptors
1 • neurones conduct impulses / electrical signals
• neurone A conducts impulses to spinal cord
(c) cools us down • neurone A = sensory neurone
allow evaporates • synapse between neurones
1 • chemical (/ neurotransmitter) crosses synapse
[6] • chemical stimulates impulse(s) in neurone B
• neurone B = relay neurone
• neurone C = motor neurone
Q2.
(a) releasing saliva when food enters the mouth • effector carries out response
1 • e.g. muscles of the arm / leg contract
• muscles contract or gland secretes chemicals
withdrawing the hand from a sharp object
1 to access level 2, candidates need to consider, in terms of the indicative
content, the receptor, the neurones and the effector in the correct sequence
(b) bright light
[11]
allow described method of increasing light
ignore light unqualified
allow correctly named drug e.g. morphine / Q3.
heroin (a) pancreas
1 1
(c) iris (b) the diabetic should get more energy from fat
1 1
(d) muscle contraction the diabetic should get less energy from carbohydrate
allow muscles shorten 1
ignore radial / circular
(c) (use) insulin
ignore muscles relax / constrict
allow pancreas / stem cell transplant
do not accept muscles expand
do not allow injection / transplant /stem cells / tablets alone
do not accept ciliary muscle contracts
1 ignore exercise
1
[4]B5 Answers/Mark scheme continued
Q4.
Q6.
(a) A
1 (a) any two from:
• drop the ruler from the same height each time
(b) E • let the ruler drop without using any force
1
• same type / weight of ruler
(c) 28 • thumb should be same distance from the ruler each time at the start
allow 27–29 • use the same hand to catch the ruler each time
1 • carry out the experiment with the lower arm resting in the same way on the
table
(d) progesterone
1 allow description of holding bottom edge of ruler opposite the
catcher’s thumb
(e) any two from: 2
• inhibits FSH production / release
(b) 117
1
• prevents egg maturation
allow prevents egg growth
• prevents ovulation (c)
allow prevents egg release 1
ignore prevents egg production
2 0.1539
(f) oestrogen
allow 01539 with no working shown for 2 marks
1 1
testosterone 0.154
allow in this order only allow 0.154 with no working shown for 3 marks
1 1
[8]
allow ecf as appropriate
Q5. (d) no indication beforehand when the colour will change
(a) (i) in the direction of the force of gravity or
1 you might be able to tell when the person is about to drop the ruler
1
(ii) against the force of gravity
1
measurement of time is more precise (than reading from a ruler)
(b) (i) diagram completed to show stem bending / leaning towards the window or
the bend / lean can be at / from any point above pot level resolution (of computer timer) is higher
1
ignore any leaves
1
(e) cerebral cortex
(ii) more light (for leaves) allow cerebrum
ignore heat 1
1
ignore identified lobes
more photosynthesis / biomass / glucose
ref to ‘more’ needed once only, eg ‘more light for (f) cerebellum
photosynthesis’ = 2 marks 1
if no other marks given allow 1 mark for ‘to get light for [10]
photosynthesis’
1B6 Answers/Mark scheme
Mark schemes
Q3.
(a) any two from:
Q1.
accept other logical / reasonable ideas
(a) chromosomes
genes (reject alleles)
• other scientists not aware of his work
alleles
for 1 mark each • chromosomes / DNA / genes not seen / discovered / known
3
do not accept there was no interest in genetics
(b) (i) sexual / sex
for one mark • other theories accepted at the time
1
• not considered to be a scientist / not eminent / respected
(ii) egg / gamete / sex cell / ovum (reject ovule)
allow ‘he was just / only a monk’
for one mark 2
1
(b) (i) random selection
(c) (i) information / genes / DNA passed from parents (reject chromosomes)
for one mark accept a method of achieving random selection
1 eg “take a handful”
if number given, minimum 20
(ii) genes / genetic information / chromosomes from two parents 1
alleles may be different
environmental effect / named may have been mutation (ii) any one from:
any two for 1 mark each
2 • 1:1 / one to one
[8]
• 19:21
Q2. accept any ratio to give correct answer, eg “50:50”
(a) do not accept 21:19 unqualified
1
st
(iii) A + a as gametes from 1 parent
1
a + a as gametes from 2nd parent
allow a alone
1
nd
(offspring / 2 generation) Aa aa
offspring must be derived from correct gametes
correct identification of yellow (Aa)
other symbols correctly used can gain full marks
3 1
(b) a gene
or
allow allele
1
green (aa) (if both given, both must be correct)
(c) 4 ignore references to previous generations
1
if no other marks awarded, both correct parental genotypes
(d) correct derivation of children’s genotypes given gains 1 mark
1
examples of award of first three marksB6 Answers/Mark scheme continued
Q5.
Q4.
(a) any two from:
(a) (i) variation (in population) / mutation • so that they do not have specific genetic defects
1
• to produce docile cats or so they are not aggressive
longer nosed individuals get more food / leaves allow descriptions of aggression such as biting and
allow longer nosed individuals more likely to survive scratching
1 • for aesthetic reasons
allow descriptions of suitable aesthetic reasons
(these) survivors breed (more) 2
1
(b) (cats) are more likely to pass on (recessive) disorders
pass on genes / alleles / DNA (for long nose) or
allow pass on mutation more likely to be susceptible to diseases
1 1
(ii) Phiomia / ancestor stretched its nose (during its lifetime) to reach food / (c) Level 2 (3–4 marks):
leaves A detailed and coherent explanation is given, which logically links the process of
1 selective breeding with explanations of how this produces cats that do not cause
allergic reactions.
passed on (stretched nose) to offspring
allow offspring inherit (stretched nose) Level 1 (1–2 marks):
Simple statements are made relating to process of selective breeding, but no
do not allow ref to genes
1 attempt to
link to explanations.
(b) (i) insufficient evidence / no proof
0 marks:
ignore other theories, eg religion
No relevant content.
do not allow no evidence
1 Indicative content
mechanism of inheritance not known process:
allow genes / DNA not discovered • parents with the desired characteristic are selected
1 • the parents are bred together to produce offspring
• offspring with the desired characteristics are selected and bred
(ii) God made all living things / them • this is repeated over many generations.
allow creationism
ignore religion explanations:
1 • parents who produce the least Fel D1 are initially selected
[9] • in their offspring there will be individuals with differing amounts of Fel D1
produced
• care is taken to ensure cats are healthy and avoid possible problems
associated
with selective breeding
• over time the population of (selectively bred) cats will produce less Fel D1
4
[7]B6 Answers/Mark scheme continued
Q6.
(a)
Classification
Name
group
Class Mammalia
Order Primates
Family Lemuroidea
Species catta
all 4 correct = 2 marks
2 or 3 correct = 1 mark
0 or 1 correct = 0 marks
2
(b) Lemur catta
ignore capitalisation / non-capitalisation of initial
letters
ignore italics / non-italics
ignore underlining / non-underlining
1
(c) carried by (favourable) currents on masses of vegetation
allow description of currents from Figure 2
ignore swimming
1
(d) isolation of different populations
1
habitat variation between lemur populations
allow examples − biotic (e.g. food / predators) or
abiotic (e.g. temperature)
1
genetic variation or mutation (in each population)
1
better adapted survive (reproduce) and pass on (favourable) allele(s) to
offspring
allow natural selection or survival of the fittest
and pass on (favourable) allele(s) to offspring
allow gene(s) / mutation as an alternative to
allele(s)
1
(eventually) cannot produce fertile offspring with other populations
allow cannot reproduce ‘successfully’ with other
populations
ignore cannot reproduce unqualified
1
[9]B7 Answers/Mark scheme
Mark schemes
Q2.
Q1. (a) any two from:
(a) Carl Linnaeus • amount of waste on each heap
1 allow size of heap
• (type of) materials on each heap
(b) Lithops
extras cancel if neither marking points one or two awarded, allow 1 mark
for same waste
ignore capitalisation / non-capitalisation
1 • put heaps in same (environmental) conditions.
e.g. keep at same (outside) temperature
allow put in same place
2
(b) microorganisms / microbes / bacteria / fungi / decomposers
ignore detritivores / examples (such as worms, maggots,
insects)
ignore pathogens / germs
(c) do not allow viruses
1 mark per line 1
extra line from adaptation negates the mark for that
(c) (i) oxygen / air added (when turning over)
adaptation
1 allow idea that decay will be aerobic
1
1 allow bacteria / microorganisms need oxygen / air
1 allow (microorganisms) respire faster
1
(d) any two from:
• cooler underground / at night (ii) any two from:
or • dead leaves / fruit / plants (fall off / onto the ground)
the jerboa can keep cool
• (fallen dead leaves / fruit / plants) decay
• loses less water
or • minerals / ions / nutrients are recycled / released.
sweats less ignore references to carbon dioxide
• less likely to be seen (by predators / prey) allow animal waste or dead animals
2 2
(e) behavioural [6]
1
[9]B7 Answers/Mark scheme continued
Q3. Q4.
(a) (i) any three from: (a) any two from:
• lights to help guide / attract fish (to the holes)
• (rigid so) holes stay open agriculture
• (holes) allow small / young fish to escape
• (so that) they can breed accept land to grow crops or graze cattle
3
buildings
(ii) (fishing) quotas / legislation
1 roads
(b) (i) movement is restricted any 2 different uses for wood for 1
1
mark each
(in a building or close together so) heat is conserved accept wood for burning (energy)
allow in heated buildings to reduce heat loss accept timber for wood
1 2
(ii) any two from: (b) (i) (USA has) more wealth / technology /
• it is cruel devices / need for electricity
allow descriptions of ‘cruelty’ 1
• disease spreads faster
• (meat) often has antibiotics in it (ii) damage done
2
e.g. pollutant / mining / non-renewable / deforestation
[8] 1
linked effect
e.g. greenhouse effect / visual pollution / run out of
resources / flooding
1
(c) (i) Problem – because some people did not want to pay the (landfill) tax
1
Waste dumped elsewhere
1
(ii) named example of
Reduce – such as less packaging / repairing
1
Reuse – such as glass bottles / shopping bags / ink jet cartridges
1
Recycle – such as metals, glass, paper
Mark as a whole
1
[10]B7 Answers/Mark scheme continued
Q5.
(a) measure the length / area of the field
1
(b) use (a) random number(s) (generator)
or
use coordinates method explained
1
(c) compare their results with another student’s results
1
place more quadrats
1
(d) 0.25 × 5 = 1.25
1
500 / 1.25 = 400
1
(40 × 400 =) 16 000
allow 16 000 with no working shown for 3 marks
1
(e) 11
1
(f) (quadrat) 5
both quadrat number and correct reason must be given for 1
mark
1
very few or only 2 growing (here)
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