0610_w14_qp_31
A paper of Biology, 0610
Questions:
6
Year:
2014
Paper:
3
Variant:
1
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2
In tulip plants, the petals can have markings called flecks. There are two alleles for flecks in tulip plants: with flecks F; and without flecks f. Explain the meaning of the term dominant allele. A tulip grower crosses two tulip plants. He finds that 76 of the offspring have petals with flecks and 23 of the offspring have petals without flecks. Complete the genetic diagram to explain this result. parental genotypes ………………… X ………………… parental phenotypes ………………… X ………………… gametes X offspring genotypes …………………………… …………………………… offspring phenotypes petals with flecks present petals without flecks The tulip grower wants to produce a pure-breeding variety of tulips with petals without flecks. State the genotypes of the parent plants he should use to produce tulip plants without flecks. Explain your answer. parental genotypes ………………… X ………………… explanation
17. Inheritance  →  17.4. Monohybrid inheritance
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The blood of a fetus does not mix with the blood of its mother, but substances are exchanged across the placenta. Table 3.1 shows five substances that cross the placenta, their direction of movement and the reason for the movement. Complete Table 3.1. The second row has been completed for you. Table 3.1 substance direction of movement reason amino acids carbon dioxide from fetus waste gas from respiration glucose oxygen urea During pregnancy, women are often given dietary advice. Explain why pregnant women require more iron and vitamin D in their diet. iron vitamin D Mothers may be encouraged to breast-feed their newborn babies. The first milk that a mother secretes is called colostrum and contains antibodies. Name the cells that produce antibodies. Explain why it is important for newborn babies to have antibodies. Some mothers bottle-feed their newborn babies with formula milk rather than breast-feed. Describe four advantages of breast-feeding, other than providing antibodies.
16. Reproduction  →  16.4. Sexual reproduction in humans
10. Diseases and immunity  →  10.1. Diseases and immunity
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Ecologists study plants and animals in their natural environment. Some ecologists inserted probes into the water-conducting tissue in trees, as shown in . The ecologists measured the time taken for water to move up from probe 1 to probe 2. probe 1 data logger probe 2 tree Name the water-conducting tissue into which the two probes were inserted. Describe how the structure of this water-conducting tissue is adapted to its function. Explain the mechanism of water movement from the roots up the tree to the leaves. shows the rate of water conduction up three different trees in a forest over 24 hours. time / h rate of water conduction / dm3 per hour 0.5 1.0 1.5 2.0 2.5 tree A tree B tree C Describe the rate of water conduction in tree A, during this 24 hour period. You will gain credit for using the data in to support your answer. Suggest how the ecologists used the data in to calculate the total volume of water used by a tree in 24 hours. In , tree A is a tall tree, tree B is a medium-height tree and tree C is a short tree. Suggest reasons for the different rates of water conduction in the three trees. Loggers often cut down the tall trees in a forest. Describe the effects on the forest ecosystem of cutting down trees.
3. Movement into and out of cells  →  3.2. Osmosis
8. Transport in plants  →  8.2. Water uptake
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shows a species of bacterium, Lactobacillus bulgaricus. List two features that distinguish bacteria from other groups of organisms. L. bulgaricus are added to milk to make yoghurt. shows the changes in a population of L. bulgaricus during fermentation to make yoghurt. number of living bacterial cells time Name the stages shown on . Write your answers in the boxes on . Explain why the population of L. bulgaricus does not continue to increase during the fermentation to make yoghurt. The curve shown in is a sigmoid population growth curve. Define the term growth. Bacteria, such as L. bulgaricus, can reproduce rapidly. Name the process of reproduction in bacteria. Sometimes food additives are added to yoghurt. Some people suggest that it is healthier to eat yoghurt without additives. Suggest the advantages and disadvantages of putting food additives into yoghurt. advantages disadvantages
19. Organisms and their environment  →  19.4. Populations
21. Biotechnology and genetic modification  →  21.1. Biotechnology and genetic modification
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Microorganisms in the soil release enzymes to digest dead leaves. Explain how enzymes catalyse chemical reactions. Protease and cellulase are two enzymes secreted by soil microorganisms. Protease digests protein. Suggest what part of the dead leaf cells are digested by the enzyme cellulase. Table 6.1 shows the results of a study comparing the decomposition of dead leaves at two locations A and B. Table 6.1 location A location B protease activity / µmol min–1 cellulase activity / µmol min–1 soil pH 6.0 3.5 soil water content / % Compare the enzyme activity at location A with the enzyme activity at location B. You will gain credit for using the data from Table 6.1 to support your answer. Suggest possible reasons for any differences in the enzyme activity at location A and location B. Describe how nitrogen in proteins in dead leaves is recycled to be absorbed by plants. Microorganisms also process and convert atmospheric nitrogen to form a nitrogen compound that can be absorbed by plants. Name this process of converting atmospheric nitrogen. Explain how this process happens.
5. Enzymes  →  5.1. Enzymes
19. Organisms and their environment  →  19.3. Nutrient cycles
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