Feb/March 2016

This equation represents a chemical reaction taking place inside living organisms. $\text{glucose} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water}$ Which characteristic of living organisms is linked to this equation?

Aerobic respiration

The table gives the conditions in four test-tubes, each containing equal amounts of starch and salivary amylase. In which test-tube is the starch broken down most quickly?

Enzymes

Plants produce their own carbohydrate supplies. Which raw materials are used in this process, and what waste product is formed?

Photosynthesis

A plant with variegated leaves is kept in a dark cupboard for 48 hours so that starch is removed from its leaves. Next, black paper is attached to one leaf, as shown, and the plant is then put in light. After 24 hours, which region of the leaf will contain starch?

Photosynthesis

The diagram illustrates part of the alimentary canal and the related organs. Which structures release enzymes that break down proteins?

Chemical digestion

The graph illustrates how pH in the mouth changes after food has been eaten. Why is it sensible to brush your teeth after eating?

Digestive system

The diagram illustrates a section of a protein molecule. What does X represent?

Biological molecules

Through which process does a leaf lose water?

Transpiration

The bottom part of a plant stem is put into water that has been coloured with red dye. After three hours, the stem is cut as shown in the diagram. Which labelled region is stained red?

Xylem and phloem

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

Heart

A cross-section of a blood vessel in the leg is shown in the diagram. Identify the kind of blood vessel illustrated, and state the direction that the blood moves in.

Blood vessels

Which of the following gives a correct name for an organism in the binomial system?

Concept and uses of classification systems

The table gives an approximate breakdown of the air exhaled by a mammal. Where does the nitrogen in the exhaled air come from?

Gas exchange in humans

What products are formed by yeast in anaerobic respiration?

Anaerobic respiration

What feature enables oxygen to enter the blood rapidly in the lungs?

Gas exchange in humans

The diagram illustrates an experiment used to study gas exchange in a leaf. In what direction will the ink drop move, and why does it move that way?

Photosynthesis

In which organ is urea produced?

Excretion in humans

The diagram illustrates the structures involved in a reflex action. In what order do impulses travel through these structures?

Coordination and response

Which structure of the human eye responds to light?

Sense organs

The diagram illustrates an experiment designed to explore how a plant stem responds to gravity. What would be an appropriate control for this experiment?

Tropic responses

Drug abuse may produce these effects: 1 addiction, 2 reduced self-control, 3 severe withdrawal symptoms. Which of these effects could result from excessive alcohol intake?

Drugs

What must be present at all times for seeds to germinate?

Sexual reproduction in plants

The diagram shows a leaf. Use the key to Identify the plant that the leaf comes from.

Leaf structure

The diagram illustrates a flower. In which structure do seeds form?

Sexual reproduction in plants

The graph illustrates the number of pregnancies among four groups of 100 women. Each group used a different contraceptive method. The contraceptive method that is least effective is

Sexual reproduction in humans

The statements below refer to some hormones in the human body. V brings about changes in the ovaries during the menstrual cycle W helps muscles become stronger and more developed X makes the voice deepen at puberty Y is made by the pancreas Which of these statements are true of testosterone?

Hormones

What substance is specified by a length of DNA?

Chromosomes, genes and proteins

What does the term alleles mean?

Chromosomes, genes and proteins

A pure-breeding plant with smooth stems was crossed with a heterozygous plant that had hairy stems. What ratio of hairy stems to smooth stems will appear in the offspring plants?

Monohybrid inheritance

Which processes form part of the carbon cycle?

Nutrient cycles

The diagram illustrates organisms that feed on a dead rat, as well as one organism that feeds on those organisms. What is required to complete the food chain?

Food chains and food webs

The diagram illustrates a food web. Which organisms consume the widest range of other organisms, according to this food web?

Food chains and food webs

The diagram illustrates how sewage is treated. Why is air bubbled through the aeration tank?

Aerobic respiration

A palisade cell and a nerve cell are viewed with a light microscope. Only the palisade cell contains a

Cell structure

Three human activities are given below. Which of these activities could bring about the change shown in the graph?

Pollution

The diagram depicts a palisade mesophyll cell from a green leaf. In which labelled part does photosynthesis take place and where is starch kept?

Leaf structure

Which row gives a description of a root hair cell?

Cell structure

The diagram shows a test-tube filled with clear jelly. A drop of blue ink is injected into the centre of the jelly. The blue colour from the ink spreads all through the jelly. By which process does the blue ink spread through the jelly?

Diffusion

Which diagram shows how the appearance of a plant cell changes after it has been kept in a concentrated sugar solution for thirty minutes?

Osmosis

The diagram illustrates a large food molecule being broken down into smaller molecules. What is process X?

Chemical digestion

Which of the following gives a correct name for an organism when the binomial system is used?

Concept and uses of classification systems

The diagram shows the shape of an enzyme molecule. Which substrate would this enzyme form an enzyme-substrate complex with most readily?

Enzymes

The table lists the conditions in four test-tubes that each contain equal amounts of starch and salivary amylase. In which test-tube does the starch break down most quickly?

Enzymes

A plant with variegated leaves is first kept in a dark cupboard for 48 hours so that the starch is removed from its leaves. Black paper is then placed over one leaf, as shown, and the plant is left in light. After 24 hours, which section of the leaf will contain starch?

Photosynthesis

Which row gives the effects on plant growth of a shortage of nitrate ions and magnesium ions?

Photosynthesis

The diagram illustrates part of the alimentary canal and the organs linked to it. Which structures produce enzymes that break down proteins?

Chemical digestion

The graph illustrates how pH in the mouth changes after eating. Why is it advisable to brush your teeth after eating?

Diseases and immunity

The lower end of a plant stem is immersed in water containing red dye. After three hours, the stem is cut as shown in the diagram. Which labelled region has turned red?

Xylem and phloem

Through which process is water lost from a leaf?

Transpiration

Which process is used to move sucrose from a plant’s leaves to its flowers?

Translocation

Which row lists the chambers of the heart in order from the thickest walls to the thinnest walls?

Heart

The diagram illustrates a leaf. Use the key to identify which plant the leaf comes from.

Concept and uses of classification systems

Why is aspirin occasionally taken as a medicine to lower the risk of coronary heart disease?

Drugs

What occurs when a child receives vaccination against tuberculosis?

Diseases and immunity

What enables oxygen to be absorbed rapidly into the blood in the lungs?

Gas exchange in humans

The diagram shows how the air pressure in the lungs changes during one full breathing cycle. The atmospheric pressure is $101\text{ kPa}$. At which point on the diagram do the ribs begin to be lowered?

Gas exchange in humans

The diagram illustrates the structure of a kidney tubule. In which part does filtration take place?

Excretion in humans

Within the eye, the fovea contains three types of cone cells, each absorbing light of a different colour. Which row is correct?

Sense organs

A person consumes a large bowl of rice. What changes occur in the amounts of insulin, glucagon and glycogen in their body?

Hormones

Which of the following is not an effect of the hormone adrenaline?

Hormones

The diagram illustrates an experiment used to study how a plant stem responds to gravity. What would be an appropriate control for this experiment?

Tropic responses

Drug abuse may lead to 1 addiction, 2 reduced self-control, 3 severe withdrawal symptoms. Which of these effects may happen after drinking too much alcohol?

Drugs

The diagram represents a palisade mesophyll cell taken from a green leaf. In which labelled part does photosynthesis take place, and where is starch kept?

Photosynthesis

Which hormone keeps the lining of the uterus during pregnancy?

Sex hormones in humans

The diagram illustrates a flower. In which structure do seeds develop?

Sexual reproduction in plants

In human sexual reproduction, why are sperm cells made in far larger numbers than egg cells?

Sexual reproduction in humans

What does the term alleles mean?

Chromosomes, genes and proteins

The diagram illustrates the sex chromosomes of a woman and a man. Their genotypes for a recessive sex-linked condition are also given. What is the likelihood that their daughter will have the sex-linked condition?

Chromosomes, genes and proteins

The diagram illustrates the inheritance of ABO blood groups. The blood groups of some individuals are shown. What might Priya’s genotype be?

Monohybrid inheritance

Which characteristic is not found in hydrophytes?

Adaptive features

The diagram displays a pyramid of numbers in a food chain. What type of organism is the hawk?

Food chains and food webs

The diagram illustrates organisms that feed on a dead rat, together with one organism that then feeds on them. What is required to complete the food chain?

Food chains and food webs

The diagram illustrates five stages in genetic engineering. Which of these stages includes the creation of sticky ends?

Genetic modification

The diagram illustrates the internal structure of a plant cell in detail. What is organelle X?

Cell structure

When nitrogenous fertiliser is used carelessly close to rivers and lakes, eutrophication may occur. This leads to fish dying. What directly causes the fish to die?

Pollution

The data present the findings from an investigation into osmosis using pieces of potato. The concentration of sugar solution is $0.6\ \text{mol per dm}^3$. The potato stick measures $60\ \text{mm}$ at the beginning and $54\ \text{mm}$ after $24$ hours. Which statements account for this change in length?

Osmosis

What is responsible for the diffusion of oxygen into a plant cell?

Diffusion

Which of the following is not an example of active transport?

Active transport

The diagram illustrates a section of DNA, with four bases marked on one strand. Which sequence of bases would appear on the opposite strand, beginning at the top?

Chromosomes, genes and proteins

The diagram illustrates a large food molecule being broken down into smaller molecules. What is process X?

Chemical digestion

The boxes on the left show the names of characteristics of living organisms, while the boxes on the right give the definitions of those characteristics. Join each characteristic to the correct definition with one straight line. One example has already been completed for you.

Characteristics of living organisms

Fig. 2.1 contains three mammals: gazelle, leopard and giraffe. The figures are not to scale.

Adaptive features

Define what is meant by the term enzyme.

Absorption

This question concerns sexual reproduction in humans.

Sexual reproduction in humans

An investigation examined blood flow in different regions of the body while resting and during mild exercise. Fig. 5.1 presents the results for the skeletal muscles, the skin and the alimentary canal.

Blood vessels

What does the term chromosome mean?

Chromosomes, genes and proteins

Fig. 7.1 shows a cross-section through part of a leaf.

Photosynthesis

Name the two parts that make up the central nervous system (CNS).

Coordination and response

A researcher examined epithelial cells taken from a human cheek using a light microscope. Fig. 1.1 is a photograph produced by the researcher of these cells.

Cell structure

Reflexes are automatic reactions that help protect the body. The route taken by nerve impulses during a reflex is known as a reflex arc.

Coordination and response

Yeast is used in bread-making. During anaerobic respiration, it produces carbon dioxide.

Anaerobic respiration

A rise in human population is associated with a shift in carbon dioxide concentration in the atmosphere. Fig. 4.1 plots the carbon dioxide concentration from 1958 to 2010, measured at Mauna Loa, Hawaii.

Nutrient cycles

Fig. 5.1 illustrates the various types of human teeth.

Digestive system

A frog species new to science was found in 2009 in the Amazon rainforest in Peru. Fig. 6.1 depicts this frog, Osteocephalus castaneicola.

Chromosomes, genes and proteins