Feb/March 2018

What feature is shared by all living organisms?

Characteristics of living organisms

The diagram shows a cross-section through part of a leaf. Which kind of cell is present in layer X?

Leaf structure

Which molecule has magnesium in it?

Photosynthesis

In what part of a mammal’s body does mechanical digestion take place?

Physical digestion

In what sequence does water move through these tissues in a plant?

Water uptake

Which blood component contains haemoglobin?

Blood

The body has defences that protect it against disease. What is meant by a mechanical barrier to disease?

Diseases and immunity

Compared with inspired air, which statement correctly describes expired air?

Gas exchange in humans

An experiment is arranged to examine the uptake of oxygen by germinating seeds. What change occurs in the levels of the coloured water at X and Y?

Aerobic respiration

Which organ controls the quantity of water in a mammal’s body?

Excretion in humans

When a boy accidentally contacts a very hot object, he instantly pulls his hand away. In this reflex action, what acts as the effector?

Coordination and response

What features do fish have?

Features of organisms

The graph illustrates how an antibiotic treatment affects bacterial populations in the blood. What conclusion can be drawn from the graph?

Diseases and immunity

Consuming alcohol before driving a car is hazardous. Which statement correctly explains why drinking alcohol and driving is hazardous?

Drugs

Which of the following statements about sexual reproduction is correct?

Sexual reproduction

The diagram illustrates a transverse section of a flower. At which location does fertilisation occur?

Sexual reproduction in plants

The graph illustrates how the thickness of the lining of the uterine wall changes over a menstrual cycle. On which day does menstruation end for the final time?

Sexual reproduction in humans

The table displays the percentage of pregnancies in four groups of women. Each group had used a different contraceptive method. Which contraceptive method was the least effective?

Sexual reproduction in humans

Which sex chromosomes in the egg and the sperm would result in a male child?

Chromosomes, genes and proteins

Cell division carries out the following functions. Which of these functions are specific to mitosis?

Mitosis

The diagram illustrates how fur colour is inherited in a small mammal. If the allele for white fur is dominant, which animal must be heterozygous for the gene that controls fur colour?

Monohybrid inheritance

Four phenotypes of a population of people were investigated. Which phenotype would show discontinuous variation?

Variation

The diagram illustrates part of a flowering plant. Using the key, identify this plant. 1 three petals $\rightarrow$ move to 2 more than three petals $\rightarrow$ move to 3 2 leaves longer than they are wide $\rightarrow$ A leaves wider than they are long $\rightarrow$ B 3 leaves are parallel-veined $\rightarrow$ C leaves that are not parallel-veined $\rightarrow$ D

Concept and uses of classification systems

Which statement concerning selective breeding is correct?

Selection

Which diagram illustrates the way energy moves through an ecosystem?

Energy flow

The diagram illustrates part of a food web. Which organisms in the food web are examples of producers, herbivores and carnivores?

Food chains and food webs

The diagram illustrates part of the carbon cycle. Which process lowers the carbon dioxide content in the atmosphere?

Nutrient cycles

Which factor will result in a reduction in population size?

Populations

A number of bacterial characteristics are given below. Which features make bacteria useful in biotechnology and genetic engineering?

Biotechnology and genetic modification

What is one product of anaerobic respiration in yeast?

Anaerobic respiration

Which statement concerning genetic engineering is correct?

Genetic modification

Deforestation has harmful impacts on the environment. Which impact contributes most to global warming?

Nutrient cycles

Methane is a gas that adds to the greenhouse effect. Which human activity produces methane?

Pollution

The diagram depicts one cell from an organism called $\textit{Spirogyra}$. Which characteristics are shared by $\textit{Spirogyra}$ and plant cells?

Cell structure

Which stage of sewage treatment gets rid of large floating items, such as plastic bags?

Pollution

What level of organisation is illustrated in the diagram?

Characteristics of living organisms

The diameter of an egg was measured as $6.5\,\text{cm}$. A student then produced a drawing of the egg, and its diameter was found to be $19.5\,\text{cm}$. What magnification did the drawing have?

Size of specimens

The diagram illustrates a plant cell. How will this cell look after it has been kept in pure water for 30 minutes?

Osmosis

When a food substance is tested using iodine solution, what colour indicates that starch is present?

Biological molecules

The graph illustrates the activity of three digestive enzymes at different pH values. Which statement is correct?

Enzymes

Biology is the science that investigates living organisms. Which characteristic is shared by every form of life?

Characteristics of living organisms

The diagram illustrates a section through part of a leaf. Which kind of cell is present in layer X?

Leaf structure

Which molecule includes magnesium?

Photosynthesis

In what region of a mammal’s body does mechanical digestion take place?

Physical digestion

While potato plants are growing, they form flowers and underground storage organs known as tubers. In this period, which parts of the plant function as sources and sinks for translocation?

Translocation

What advantage does a double circulatory system give mammals?

Circulatory systems

The body has defences that help protect it from disease. What is a mechanical barrier against disease?

Diseases and immunity

During exercise, receptors sense a change in the blood and make the breathing rate rise. What change do the receptors sense, and where in the body are they located?

Homeostasis

A practical is arranged to investigate oxygen uptake by germinating seeds. How do the levels of the coloured water at X and Y change?

Aerobic respiration

The diagram shows part of a kidney. Which labels are correct?

Excretion in humans

A boy accidentally touches an object that is very hot and instantly pulls his hand back. In this reflex action, what is the effector?

Coordination and response

Two animals possess the same amino acid sequence in one of the proteins in their cells. What does this suggest about these animals?

Chromosomes, genes and proteins

Which description of the way the pupil of the eye becomes smaller is correct?

Sense organs

There are two kinds of diabetes, type 1 and type 2. The graph presents the number of children with each type of diabetes per $100\,000$ children in one country. Which conclusion can be drawn from the graph?

Diseases and immunity

The diagram illustrates an experiment that uses wheat shoot tips to investigate plant growth. Which statement is supported by the evidence from this experiment?

Tropic responses

What features does a wind-pollinated plant have?

Sexual reproduction in plants

Which option gives the description of a human male gamete?

Sexual reproduction in humans

What effect does HIV infection have on the human body?

Diseases and immunity

Which sex chromosomes in the egg and in the sperm must combine to produce a male child?

Chromosomes, genes and proteins

Cell division performs the following roles. Which of these roles are unique to mitosis?

Mitosis

The diagram illustrates the inheritance of fur colour in a small mammal. If the allele for white fur is dominant, which animal has to be heterozygous for the gene that controls fur colour?

Monohybrid inheritance

In regions of the world where malaria occurs, the sickle-cell allele is found at a higher frequency. What is the explanation for this?

Selection

The diagram illustrates a section of a flowering plant. Use the key to identify this plant. 1 three petals lead to 2 more than three petals lead to 3 2 leaves longer than they are wide A leaves wider than they are long B 3 leaves parallel-veined C leaves not parallel-veined D

Concept and uses of classification systems

Which adaptation enables a xerophyte to survive in its environment?

Adaptive features

What is one characteristic of natural selection?

Selection

The diagram illustrates energy transfer within an ecosystem. In which form is energy passed on at X?

Energy flow

The diagram illustrates a section of the carbon cycle. Which process decreases the carbon dioxide content in the atmosphere?

Nutrient cycles

The graph illustrates how the human population of the world has changed over the last 2000 years. What phase is indicated by P?

Populations

Some characteristics of bacteria are given. Which of these characteristics make bacteria useful in biotechnology and genetic engineering?

Biotechnology and genetic modification

Which condition is needed for penicillin production in a fermenter?

Biotechnology

Large amounts of human insulin may be made using modified $E.\ coli$ bacteria. Four stages in this production method are given below. In which order do these stages occur?

Genetic modification

What is one major factor that contributes to the problem of famine across the world?

Food supply

The flow diagram illustrates a process that may happen because of pollution in a river. Which term names the process shown in the flow diagram?

Pollution

The diagram depicts one cell from an organism named Spirogyra. Which characteristics does Spirogyra have in common with plant cells?

Cell structure

At which treatment stage of sewage are large floating items, such as plastic bags, removed?

Pollution

A student was informed that a diagram of a bacterial cell had been enlarged 30 000 times. The diagram measured $45\text{ mm}$ in length. What was the bacterium’s actual length?

Size of specimens

Which graph shows the effect of a rise in temperature on the rate of diffusion?

Diffusion

Protoplasts are plant cells from which the cell wall has been removed. What occurs if plant protoplasts are put into distilled water?

Osmosis

When a food substance is tested using iodine solution, which colour indicates that starch is present?

Biological molecules

The graph illustrates the activity of three digestive enzymes at different pH levels. Which statement is correct?

Enzymes

Table 1.1 gives a list of chemicals that are useful to humans. Complete Table 1.1 by giving one use for each chemical.

Biological molecules

Fig. 10.1 illustrates a section of the water cycle. The letters stand for the processes occurring within the water cycle.

Nutrient cycles

Fig. 2.1 shows a cross-section through a blood vessel.

Blood

The boxes on the left show the names of structures in the body. The boxes on the right show the names of processes carried out by the body. Join each structure to the process it is involved in with one straight line. Draw six lines.

Characteristics of living organisms

The kidneys remove surplus water by passing it out in urine.

Excretion in humans

Fig. 5.1 presents a diagram of a cell from a leaf.

Cell structure

This question concerns enzymes. Use the words in the list to fill each gap. A word can be used once, more than once, or not used at all. amino acids, amylase, bacteria, biological, fatty acids, glucose, humidity, lipase, living, protease, salivary, temperature

Enzymes

Certain animals make milk to nourish their young. Table 7.1 gives the mass of the substances present in 100 g of milk from two animals.

Diet

Define what is meant by pollination.

Sexual reproduction in plants

Some insects are able to reproduce by sexual reproduction as well as asexual reproduction. In both forms, chromosomes are transferred from the parent or parents to the offspring. Fig. 9.1 is a sketch of a parent insect and seven of her offspring: M, N, P, R, S, T and U.

Variation

Fig. 1.1 is a branching key for identifying different species of bacteria. Fig. 1.2 presents six different species of bacteria. Use the key to identify the six different species of bacteria. Place the letters on the lines in Fig. 1.2.

Concept and uses of classification systems

A study was conducted to estimate how many people in India had chronic obstructive pulmonary disease (COPD). Information was gathered from two sets of people: those living in cities and those living in villages. Fig. 2.1 presents the outcomes.

Gas exchange in humans

Ecologists surveyed a patch of woodland and estimated the biomass at each trophic level for one food chain in that woodland. Some students wished to use these data to sketch a pyramid of biomass for the food chain. Table 3.1 displays the students’ table. The students also added a column so that they could work out the width of the bars they would need to draw.

Food chains and food webs

Fig. 4.1 shows a diagram of the human female reproductive system.

Sexual reproduction in humans

2,4-D is a synthetic plant auxin used as a weedkiller. Researchers tested how effective different 2,4-D treatments were at controlling the weed Conyza canadensis in maize, Zea mays, fields. The findings are given in Table 5.1.

Tropic responses

Define what chemical digestion means.

Chemical digestion