Feb/March 2021

Woodlice are small organisms that live in moist habitats. In an experiment, three live woodlice are placed inside a glass container. The diagram shows the situation after $30$ minutes. Which characteristic of living organisms is demonstrated by this experiment?

Characteristics of living organisms

An experiment used a human enzyme. Every factor except temperature was held constant. What occurred to the rate of reaction as the temperature was lowered steadily from $35^{\circ}\text{C}$ to $5^{\circ}\text{C}$?

Enzymes

Which graph shows how pH affects the activity of a digestive enzyme?

Enzymes

During which process is oxygen produced as a waste product?

Photosynthesis

The table presents diagrams of three cell types found in a leaf. Which row correctly names each cell type?

Leaf structure

In which part of the body does egestion occur?

Digestive system

The diagram shows a tooth with signs of decay. What is responsible for the hole in the enamel of the tooth?

Diseases and immunity

The diagram shows enzymes and the products formed in the reactions that they catalyse. Which diagram correctly pairs each enzyme with its product?

Enzymes

Which statement correctly describes one function of xylem tissue?

Xylem and phloem

What forms part of the definition of transpiration?

Transpiration

Which structures prevent blood from flowing in the reverse direction in the human circulatory system?

Heart

Which species is able to breed with $\textit{Prunella vulgaris}$ in order to produce fertile offspring?

Concept and uses of classification systems

The diagram shows a cross-section of the heart. Which chamber pumps blood to the aorta?

Heart

Which defence stops pathogens from entering the body?

Diseases and immunity

The air that enters human lungs contains about 21% oxygen and 0.04% carbon dioxide. Which row gives the concentrations of these gases in the air that leaves the lungs?

Gas exchange in humans

What products are formed during anaerobic respiration in yeast?

Anaerobic respiration

The diagram illustrates the human excretory system together with the blood vessels linked to it. Which structures are X, Y and Z?

Excretion in humans

Sensory neurones relay impulses from

Sense organs

The diagram illustrates a cross-section of human skin. Which row correctly pairs the labelled part with its function?

Sense organs

The diagram depicts a seedling growing in a pot in the light. The pot was then laid on its side in a dark room. What will the seedling look like after 48 hours?

Tropic responses

Heroin is an illegal drug that affects the body in many ways. Which statement about the effects of heroin abuse is correct?

Drugs

What process is taking place at X?

Diffusion

Which sequence of arthropod groups is correct, arranged from the group with the greatest number of legs to the one with the fewest?

Features of organisms

Which diagram of the male reproductive system has the labels placed correctly?

Sexual reproduction in humans

Which birth-control method prevents an egg from being released?

Sexual reproduction in humans

What term is used for ‘a thread-like structure of DNA, carrying genetic information in the form of genes’?

Chromosomes, genes and proteins

The diagram illustrates the formation of a male embryo. Which row identifies the sex chromosomes in the cells and the type of cell division at P?

Mitosis

Foxes belong to the mammal group. The table lists adaptations of four different fox species. Which fox is most suited to living in a hot, dry desert area?

Adaptive features

What is the main source of energy that enters food chains?

Energy flow

How would reducing forest cover affect the concentration of carbon dioxide in the atmosphere?

Nutrient cycles

State one example of a population.

Populations

In the extraction of apple juice, ripe apples are crushed and the enzyme pectinase is then added. Which observation indicates that pectinase has been used to make the apple juice?

Enzymes

Rice has been genetically altered by inserting genes from bacteria and another plant, enabling it to produce the nutrient beta carotene. What is this process called?

Genetic modification

The diagram illustrates four animal cells, viewed using a light microscope. What would be found at X?

Cell structure

What does screening remove during the treatment of sewage?

Pollution

The diagram illustrates a root hair cell. How is this cell adapted for the absorption of water?

Water uptake

The diagram is a sketch of part of a tulip flower. The stigma’s real width, represented by the line $PQ$, is $5\,\text{mm}$. The length of line $PQ$ is $15\,\text{mm}$. What is the magnification of the diagram?

Size of specimens

An upside-down jar of air was positioned above a jar that contains a brown gas, as illustrated. Which process has occurred?

Diffusion

Which row gives the definition of active transport?

Active transport

Each of these nutrients was investigated in four foods: fat (with the ethanol emulsion test), protein (with the biuret test), reducing sugar (with Benedict’s solution). Which food has both protein and fat?

Biological molecules

Woodlice are small organisms that live in moist places. In an experiment, three living woodlice are placed in a glass container. The diagram shows the result after 30 minutes. Which characteristic of living organisms is demonstrated by this experiment?

Characteristics of living organisms

The graph illustrates how temperature changes the rate of an enzyme-controlled reaction. Which statements are correct?

Enzymes

Which graph shows how pH affects the activity of a digestive enzyme?

Enzymes

During which process is oxygen formed as a waste product?

Photosynthesis

Identify the leaf layer that contains interconnecting air spaces?

Leaf structure

In which location does egestion occur?

Digestive system

The diagram displays a fat globule (P) in one section of the alimentary canal and the same fat globule (Q) as it is seen in a different section of the alimentary canal. In which sections of the alimentary canal are P and Q located?

Physical digestion

The diagram illustrates enzymes and the products formed by the reactions that they catalyse. Which diagram pairs the enzymes with the correct products?

Enzymes

Which statement about a function of xylem tissue is correct?

Xylem and phloem

What forms part of the definition of transpiration?

Transpiration

The diagram illustrates blood circulation in an organism. In which part of the organism is the box located showing the capillaries?

Blood vessels

Which species is able to interbreed with Prunella vulgaris and produce fertile offspring?

Concept and uses of classification systems

The photomicrograph displays human blood. Which blood component is able to perform phagocytosis?

Blood

Which diagram illustrates how vaccination can produce long-term immunity?

Diseases and immunity

Air taken into the human lungs contains about 21% oxygen and 0.04% carbon dioxide. Which row gives the concentrations of these gases in air exhaled from the lungs?

Gas exchange in humans

After completing a sprint race, a student felt pain in the muscles of their leg. This pain was due to the accumulation of a product formed during anaerobic respiration. Which product was responsible for the pain?

Anaerobic respiration

The diagram illustrates the formation and removal of materials from the human body. What do V, W, X, Y and Z represent in the diagram?

Excretion in humans

What does a synapse do?

Coordination and response

Hormones and the nervous system both regulate the body. Which statement about the control exerted by hormones is correct?

Hormones

Auxin is a chemical synthesised by plants. It regulates plant growth. Which statement about auxin is correct?

Hormones

In what way do some antibiotics kill bacteria?

Drugs

A number of statements about asexual reproduction are given. Which of these statements are correct?

Asexual reproduction

What is the correct sequence of arthropod groups, beginning with those that have the greatest number of legs and ending with those that have the smallest number of legs?

Features of organisms

What kinds of human contact are able to transmit HIV?

Sexually transmitted infections

Which birth-control method prevents release of an egg?

Sex hormones in humans

How would you define ‘a thread-like structure of DNA, carrying genetic information in the form of genes’?

Chromosomes, genes and proteins

The statements below show stages in protein synthesis. 1 Copies of the gene are moved to the cytoplasm as mRNA molecules. 2 Each ribosome links amino acids together to make a protein molecule. 3 The gene that codes for a protein is copied in the nucleus. 4 The mRNA molecules move through ribosomes. Which order of steps is correct?

Chromosomes, genes and proteins

A sunflower contains 17 chromosomes in each pollen nucleus. These nuclei are formed by the process of in the anthers. They are genetically all the pollen nuclei produced by those anthers. Once fertilisation has occurred, the zygote that is formed will have chromosomes. Which row correctly fills gaps 1, 2 and 3?

Mitosis

A male who is heterozygous for the sickle cell anaemia allele, Hb$^{S}$Hb$^{A}$, has children with a female who is homozygous for the normal haemoglobin allele, Hb$^{A}$Hb$^{A}$. What is the chance that the first child will be resistant to malaria?

Monohybrid inheritance

Which leaf characteristic acts as an adaptation of xerophytes to their environment?

Adaptive features

The graph illustrates how the population of an organism changes over time in an ecosystem. Which row correctly names each phase of the population graph?

Populations

The diagram illustrates the organisation of a bacterium. One reason that bacteria are used in genetic engineering is that they contain structure X. What is structure X?

Genetic modification

When nitrates get into a lake, they trigger a fast increase in algae growing across the water surface. As a result, the following changes happen in the lake: 1 The amount of dissolved oxygen in the water falls. 2 Fish and other aquatic animals die. 3 Aerobic respiration in decomposers rises. 4 Producers die and decomposition rises. What is the correct sequence for these changes?

Nutrient cycles

The diagram displays four animal cells, viewed using a light microscope. What is located at X?

Cell structure

Which type of bacteria would, through its activity, leave the soil short of nitrates?

Nutrient cycles

The diagram illustrates a root hair cell. In what way is this cell adapted for absorbing water?

Water uptake

A student makes a drawing of a mitochondrion. This diagram is shown at a magnification of $\times 20000$. Its length on the page is 5 cm. What is the mitochondrion's actual size?

Size of specimens

An inverted jar of air was set on top of a jar that contained a brown gas, as illustrated. Which process has occurred?

Diffusion

Which row gives a description of active transport?

Active transport

On one strand of a DNA molecule, the bases are arranged in the order CAGCT. What base sequence is found on the complementary strand?

Chromosomes, genes and proteins

Fig. 1.1 shows the alimentary canal together with the organs linked to it.

Digestive system

People from different age groups in one area were questioned about their tobacco-smoking habits. Fig. 2.1 is a graph showing the percentage of people who currently smoke tobacco and the percentage of people who used to smoke tobacco but have since given it up.

Gas exchange in humans

Fig. 3.1 presents a food web.

Selection

Identify the parts of the plant cell in Fig. 4.1 by filling in the spaces provided with words from the list.

Xylem and phloem

A student carried out an investigation into how the concentration of carbon dioxide affects the rate of photosynthesis in an aquatic plant. The findings are shown in Table 5.1.

Photosynthesis

Join the left-hand box to three boxes on the right so that you make three correct sentences.

Anaerobic respiration

Fig. 7.1 shows the circulatory system.

Blood vessels

State the age at which first menstruation most commonly occurred.

Sexual reproduction in humans

Fig. 1.1 is a diagram that shows the locations of some organs in the human body. Some of the organs in Fig. 1.1 are endocrine glands. Table 1.1 gives the names of some endocrine glands, their identifying letters, and the hormones they produce. Complete Table 1.1.

Sex hormones in humans

State one visible feature in Fig. 2.1 that shows this cell is prokaryotic.

Cell structure

Heart activity can be tracked in several ways. Fig. 3.1 presents two ECG traces: one was taken while the person was resting and the other while they were exercising. In the ECG trace recorded at rest, Fig. 3.1 marks the time taken for one heart beat.

Heart

What does the term organ mean?

Photosynthesis

Measles is a communicable disease. The proportion of the population in a country that had been vaccinated against measles was measured, and the number of confirmed measles cases in that country was also noted. Fig. 5.1 presents the data gathered from 1975 to 2010.

Diseases and immunity

Fig. 6.1 presents a food web.

Food chains and food webs