Feb/March 2017

The illustration shows a ground squirrel. Which characteristic identifies this animal as a mammal?

Features of organisms

Which substances take part in photosynthesis?

Photosynthesis

Which term means the taking of substances into the body through the mouth?

Digestive system

What is required to produce the haemoglobin in red blood cells?

Blood

The diagram shows a tooth that is decayed. What caused the hole in the enamel of the tooth?

Diseases and immunity

Four leafy plant stems were each put into measuring cylinders containing $100\, \text{cm}^3$ of water. An oil layer stopped the water in the measuring cylinder from evaporating. The stems were then kept in air with different humidities and temperatures for $48$ hours, as listed in the table. The final volume of water left in the measuring cylinders is given for plant stems 1, 3 and 4. What is a likely final volume for plant stem 2?

Transpiration

Which blood vessel, if it were blocked, could cause a heart attack directly?

Blood vessels

A patient in hospital who feels unwell has a blood test. The blood test results indicate a very low platelet count. What effect is this likely to have?

Blood

What does the term pathogen mean?

Diseases and immunity

The graph shows a person’s breathing rate and breathing depth before exercise. Which graph shows the breathing rate and breathing depth of the same person immediately after a period of exercise?

Gas exchange in humans

In an experiment, three glass bell jars were arranged as shown in the diagram. When the experiment ended, which bell jar contained the greatest amount of oxygen and which contained the least?

Photosynthesis

The diagram illustrates how a seed changes once it has been planted in soil and watered. Which characteristics of living things are shown by this sequence?

Characteristics of living organisms

Which substances are produced during anaerobic respiration in muscles?

Anaerobic respiration

Which substance stays in the blood as it flows through the kidney?

Excretion in humans

When the nervous system reacts to a stimulus, the response happens in several stages. 1. The receptors pick up the stimulus. 2. A nerve impulse is carried to the central nervous system. 3. The central nervous system interprets the information. 4. A nerve impulse is carried to the muscles. 5. A response is made. What is the correct sequence of these stages?

Coordination and response

In which regions of the body are receptors for blood temperature found?

Homeostasis

Which row indicates the effects of increased adrenaline release?

Hormones

Which of these statements correctly describes the growth response of a plant shoot?

Tropic responses

A patient has an infection. Her doctor gives her an antibiotic. After one week, the infection is still there. What might explain this?

Diseases and immunity

The diagram shows Hydra growing and then releasing an offspring from one side of its body. Which row is correct?

Asexual reproduction

The photograph displays the structures required for reproduction in the flower of a dicotyledon. What part is labelled P?

Sexual reproduction in plants

What is the name of the organ where a human fetus develops until birth?

Sexual reproduction in humans

The diagram shows a palisade cell from a leaf. In what way is a palisade cell unlike the other cells in the same plant?

Leaf structure

What would provide protection against a sexually transmitted infection?

Sexually transmitted infections

Which term refers to the passing of genetic information from one generation to the next?

Chromosomes, genes and proteins

What does the term gene mean?

Chromosomes, genes and proteins

Which process includes meiosis?

Meiosis

The allele for brown coat colour is dominant over the allele for albino coat colour. A mammal that is homozygous for brown coat colour is crossed with a mammal that is heterozygous for brown coat colour. What percentage of the offspring are expected to be albino?

Monohybrid inheritance

Which statement gives the correct description of an adaptive feature?

Adaptive features

The diagram illustrates part of the carbon cycle. What is represented by arrow X?

Nutrient cycles

The diagram illustrates the water cycle. What processes are shown by Y and Z?

Nutrient cycles

What is put into a bacterium so that the bacterium produces insulin?

Genetic modification

The graph illustrates world wheat production between 1950 and 2000. What factors have led to the changes shown in wheat production?

Food supply

The diagram shows a number of cells. In which part of the body are these cells found?

Leaf structure

Which graph illustrates how pollution from untreated sewage affects the amount of oxygen dissolved in a river?

Pollution

A specimen shown in a photograph measures $45\,\text{mm}$ in length. Its real length is $25\,\text{mm}$. What magnification does the photograph have?

Size of specimens

The diagram illustrates a cross-section of a leaf. Which arrow indicates the direction in which carbon dioxide diffuses on a sunny day?

Leaf structure

The diagram shows two liquids with a membrane between them, allowing osmosis to take place. Which statement explains the way the molecules will move?

Osmosis

Which element is present in proteins but absent from carbohydrates?

Biological molecules

Two samples of a human enzyme were used in an experiment. Before use: • sample X was heated to $80\, ^\circ\text{C}$ and then allowed to cool to $37\, ^\circ\text{C}$, • sample Y was cooled to $0\, ^\circ\text{C}$ and then warmed to $37\, ^\circ\text{C}$. How will this change their activity?

Enzymes

An illustration shows a ground squirrel. Which characteristic shows that this animal is a mammal?

Features of organisms

Which substances take part in photosynthesis?

Photosynthesis

Which term means the intake of substances into the body through the mouth?

Digestive system

Which nutrient is lacking in the diet of a child who has kwashiorkor?

Diet

The diagram shows a tooth that has signs of decay. What has caused the gap in the tooth’s enamel?

Diseases and immunity

Which option gives a description of translocation?

Translocation

Which one of the following describes a function of the lymphatic system?

Circulatory systems

A patient in hospital who feels ill has a blood test. The blood test results show a very low platelet count. What effect would this cause?

Blood

Which feature is common to both active immunity and passive immunity?

Diseases and immunity

The graph illustrates a person’s breathing rate and depth before exercise. Which graph represents that same person’s breathing rate and depth immediately after exercising?

Gas exchange in humans

A set of three glass bell jars was arranged as shown in the diagram. Bell jar P: a green plant was kept in sunlight for 8 hours. Bell jar Q: was left open to the air for 8 hours. Bell jar R: contained air breathed out by a student for 5 minutes. After the experiment, which bell jar contains the greatest amount of oxygen and which contains the smallest amount?

Photosynthesis

The diagram illustrates the changes that a seed undergoes once it has been sown in soil and watered. Which characteristics of living things are shown by this sequence?

Characteristics of living organisms

Which products are formed by anaerobic respiration in muscles?

Anaerobic respiration

Which substance stays in the blood as it flows through the kidney?

Excretion in humans

The diagram illustrates the mechanisms that regulate the concentration of glucose in the blood. Which row correctly names the glands and hormones labelled W, X, Y and Z?

Hormones

Which row indicates the effects of a greater release of adrenaline?

Hormones

The graph illustrates how a plant’s photosynthesis rate varies as light intensity changes, at three different carbon dioxide concentrations. In every case, the temperature is $15^\circ \text{C}$. Which factor is limiting the rate of photosynthesis at point X on the graph?

Photosynthesis

State one benefit of asexual reproduction for a population of flowering plants in the wild.

Asexual reproduction

In plant sexual reproduction, what will produce the widest variation among the offspring?

Sexual reproduction in plants

The diagram illustrates the head of a sperm. What is the role of structure X?

Sexual reproduction in humans

Which hormone is administered to women receiving fertility treatment?

Sex hormones in humans

The diagram shows sperm and ovum joining together during fertilisation. Which statement about cell X is correct?

Sexual reproduction in humans

The diagram illustrates a section of the classification of the animal kingdom and gives one example of each group. Which pair of animals is shown by the classification to share the most recent common ancestor?

Concept and uses of classification systems

A cell that has 16 chromosomes divides twice by mitosis. How many chromosomes are in each of the cells formed?

Mitosis

A man with genotype $I^A I^O$ and a woman with genotype $I^B I^O$ have a child. What is the probability that the child will have the same blood group as one of the parents?

Monohybrid inheritance

Which human phenotype is influenced by both environmental and genetic factors?

Variation

Which adaptation might be found in a xerophyte?

Adaptive features

In what way does artificial selection differ from natural selection?

Selection

The diagram illustrates the energy contained in a food chain: $40\,000\ \text{kJ}$ photosynthesising phytoplankton $\rightarrow$ $4000\ \text{kJ}$ krill $\rightarrow$ $400\ \text{kJ}$ herring $\rightarrow$ $40\ \text{kJ}$ bass. What percentage of the energy in the producer is passed on to the secondary consumer?

Energy flow

Which process causes nitrates to be removed from soils?

Nutrient cycles

In the exponential (log) stage of a sigmoid growth curve, which factor constrains population growth?

Populations

Genes are removed from human DNA by means of ……1…… enzymes. A bacterial plasmid is then cut by the same enzyme, producing ……2…… . The human DNA is joined into the bacterial plasmid using the enzyme ……3……, creating a ……4…… plasmid. Which row completes spaces 1, 2, 3 and 4 correctly?

Genetic modification

In what way does the removal of trees add to the greenhouse effect?

Nutrient cycles

The diagram shows a specimen of material collected from an organism. Which level of organisation is shown by the specimen?

Characteristics of living organisms

What graph illustrates the effect of pollution from untreated sewage on the amount of oxygen dissolved in a river?

Pollution

A specimen measures $45\,\text{mm}$ in a photograph. Its real length is $25\,\text{mm}$. What magnification does the photograph show?

Size of specimens

The diagram represents a cross-section of a leaf. Which arrow indicates the direction in which carbon dioxide diffuses on a sunny day?

Leaf structure

The diagram shows two liquids separated by a membrane that allows osmosis to take place. Which statement explains how the molecules will move?

Osmosis

Which element is present in proteins but not in carbohydrates?

Biological molecules

A large number of enzymes stop functioning at temperatures above $60\,^{\circ}\text{C}$. Which statement gives the explanation?

Enzymes

The boxes on the left show the names of glands that release enzymes. The boxes on the right list the digestive enzymes. A few glands make more than one enzyme.

Chemical digestion

Fig. 2.1 is a diagram of the heart.

Heart

Fig. 3.1 depicts a reflex arc.

Coordination and response

The boxes on the left list cells and tissues adapted for a specific role. The boxes on the right give the descriptions of those specialised roles.

Features of organisms

Define the biological term species.

Concept and uses of classification systems

State the word equation that represents photosynthesis.

Photosynthesis

Fill in the sentences about the enhanced greenhouse effect.

Habitat destruction

Fig. 8.1 presents a section of a food web.

Food chains and food webs

Fig. 9.1 illustrates the male reproductive system from a side view.

Sexual reproduction in humans

Fig. 1.1 presents a vertical section of a human heart together with the main blood vessels.

Heart

Bacteria are placed in the Prokaryote kingdom. MRSA is a bacterium that shows resistance to antibiotics. The number of MRSA cases found in hospitals in the USA from 1995 to 2005 was recorded. Fig. 2.1 presents these data.

Features of organisms

Colour blindness in humans is the result of a defect in some of the light receptor cells in the retina of the eye. Rod cells and cone cells are the two kinds of light receptor.

Monohybrid inheritance

Water is one requirement for photosynthesis. Table 4.1 gives the number of hectares of forested land in several African countries for 1990, 2000 and 2005.

Transpiration

Yeast, which is a microorganism, can be used to make alcohol.

Enzymes

Table 6.1 presents several enzymes together with their substrates, products and the parts of the digestive system where they are formed.

Chemical digestion