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1. (a) Fig. 1.1 is a photomicrograph showing a cross-section of an artery.
On Fig. 1.1, identify and label the:
- artery wall
- lumen. [2]
(b) Complete the table by circling the correct words to show the differences between arteries and veins.
[Table_1]
- type of blood vessel
- relative thickness of the wall
- relative diameter of the lumen
artery thick / thin wide / narrow
vein thick / thin wide / narrow [2]
(c) State the name of the structures in veins that ensure one-way flow of blood. [1]
(d) Fig. 1.2 is a simplified diagram of the circulatory system in humans.
(i) State the names of the organs represented by the letters A, B and C in Fig. 1.2. [3]
(ii) Draw two arrows on Fig. 1.2 to show the direction of blood flow in the pulmonary vein and the pulmonary artery. [1]
(e) State the name of the blood vessels that transfer substances to and from cells. [1]
(f) Circle the names of two waste substances that are transferred from cells to blood.
amino acids carbon dioxide fatty acids
glucose oxygen urea [2]
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2. (a) Tick (✓) all the boxes that describe enzymes.
- they are permanently changed by the reaction
- they are involved in all metabolic reactions
- they are proteins
- they are solvents
- they slow down all chemical reactions [2]
(b) Fig. 2.1 shows the effect of pH on the activity of three different digestive enzymes, X, Y and Z.
Using the information in Fig. 2.1:
(i) State the optimum pH of enzyme Z. [1]
(ii) State a pH value at which both enzymes X and Y are active. [1]
(iii) State a pH value at which enzyme Y is completely denatured. [1]
(iv) Enzyme X is a protease. Describe its location and action in the digestive system. [2]
(v) Enzyme Y is produced by the salivary glands. State the substrate and product of enzyme Y. [2]
(c) State the type of digestion that uses enzymes. [1]
(d) State one factor, other than pH, that affects enzyme activity. [1]
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3. (a) Fig. 3.1 is a diagram of part of the carbon cycle.
Three processes that occur in the carbon cycle are labelled Q, R and S.
(i) Complete the table by stating the names of processes Q, R and S in Fig. 3.1. [3]
(ii) Draw one arrow on Fig. 3.1 to represent the transfer of carbon by respiration in herbivores. [1]
(b) Carbon dioxide is one gas that causes climate change.
State the name of one other gas that causes climate change. [1]
(c) Suggest one way that humans can increase the rate of removal of carbon dioxide from the atmosphere. [1]
(d) Proteins contain carbon.
State two other chemical elements all proteins contain. [2]
(e) Describe what is meant by the term carnivore. [1]
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4. A population of a species of fish was accidentally introduced into a lake.
(a) State two features that can be used to classify this introduced species as a fish. [2]
(b) Describe what is meant by the term population. [2]
(c) Fig. 4.1 shows the changes in the population size of the introduced fish species in the lake between 2004 and 2010.
(i) The boxes on the left show the letters identifying the sections of the graph in Fig. 4.1. Draw lines to link each letter with the correct phase.
Draw three lines.
A
B
C
death
exponential (log)
lag
stationary [3]
(ii) Describe possible reasons for the change in population size between 2009 and 2010 in Fig. 4.1. [3]
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5. (a) A student investigated the effect of windspeed on the rate of transpiration.
The student placed a fan at different distances from a plant shoot and measured the distance the air bubble moved in three minutes.
The distance the air bubble moved can be used to calculate the rate of water uptake, which is equivalent to the rate of transpiration.
Fig. 5.1 shows the apparatus the student used.
Table 5.1 shows their results.
[Table_2]
(i) Calculate the rate of water uptake when the fan is 0.6 m from the plant shoot. Give your answer to two decimal places. [2]
(ii) Using the information in Fig. 5.1 and Table 5.1, complete the sentences by writing a word or phrase in the spaces to describe the results. [5]
(iii) State one other factor that affects the rate of transpiration. [1]
(b) State two uses of water in a plant. [2]
(c) Explain why the leaf can be described as an organ. [2]
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6. Fig. 6.1 is a photograph of intensive egg production on a chicken farm.
(a) In 1905, each chicken produced a mean of 120 eggs per year. In 2021, each chicken produced a mean of 300 eggs per year.
Calculate the percentage increase in mean egg production per year. [2]
(b) Egg production has increased due to selective breeding and intensive farming. Describe the disadvantages of intensive livestock farming. [3]
(c) Complete the flowchart to describe how egg production in chickens is increased by selective breeding.
identify the chickens that ...
use these chickens to ...
observe the offspring for improvement in egg production
repeat this process over many ... [3]
(d) Selective breeding is also used to increase crop plant production.
State two other ways to increase crop plant production. [2]
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7. (a) A scientist investigated the effect of the enzyme pectinase on the volume of fruit juice produced by the same mass of two different fruits.
Fig. 7.1 shows the results.
Describe the results shown in Fig. 7.1. [3]
(b) State two components of a balanced diet that are provided by fruits such as blackcurrants and plums. [2]
(c) State two reasons why bacteria are useful in biotechnology and genetic modification. [2]
(d) The box on the left contains the beginning of a sentence. The boxes on the right show some sentence endings.
Draw two lines to make two correct sentences.
Genetic modification ... [2]
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8. (a) Alveoli are the gas exchange surfaces in humans.
(i) State two features of gas exchange surfaces in humans. [2]
(ii) State the name of the organ system alveoli belong to. [1]
(b) State the word equation for aerobic respiration. [2]
(c) Explain why muscle cells have a high rate of respiration. [2]
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