Feb/March 2023

Which row identifies the substances eliminated by excretion?

Excretion in humans

What substances are enzymes composed of?

Biological molecules

What is left at the end of an enzyme-controlled reaction?

Enzymes

A plant is kept in darkness until every bit of its stored starch has been used. It is then put into light, with black paper covering part of one green leaf. After eight hours, the leaf is tested for starch. Which diagram shows how the leaf appears after this test?

Photosynthesis

The diagram shows part of a leaf cross-section. Which row gives the correct labels?

Leaf structure

The diagrams illustrate the various kinds of human teeth. Which teeth are used to grind food?

Physical digestion

Which row gives the correct names for parts of the large and small intestines?

Digestive system

The diagram illustrates the apparatus used in an experiment. The apparatus was maintained at $35\,^{\circ}\text{C}$. What is likely to be present in the water around the membrane after 45 minutes?

Diffusion

The arrows indicate the transfer of substances from the soil into a root hair cell. Which substances pass from the soil into the root hair cell?

Water uptake

Through which process does water vapour pass out from the stomata in leaves?

Transpiration

Which row concerning the circulatory system is correct?

Circulatory systems

Which two components make up the scientific name of an organism?

Concept and uses of classification systems

In coronary heart disease, which structures can be blocked?

Blood vessels

What term is used for a disease-causing organism?

Diseases and immunity

A student carried out an investigation into how temperature affects respiration in yeast. The diagram shows the apparatus they used. Which substance caused the indicator to change from clear to cloudy?

Anaerobic respiration

The apparatus illustrated was used to study aerobic respiration in seeds. It was kept in a dark room. Every environmental condition was maintained constant. What will happen in the apparatus?

Aerobic respiration

What is the reason for using yeast in bread-making?

Anaerobic respiration

In the diagram, which label shows the urethra?

Excretion in humans

The diagram illustrates a reflex arc. Which label indicates the motor neurone?

Coordination and response

What function does insulin have?

Hormones

The diagram shows a seedling growing within a dark box. What type of responses determine the direction of growth of the root and the shoot inside the box?

Tropic responses

Which row explains why antibiotics can successfully treat only some infections?

Diseases and immunity

How many jointed legs are there on an insect?

Features of organisms

The diagram shows a section of a flower. What is the name of the part marked X?

Sexual reproduction in plants

Which of the following statements about the hormones involved in human puberty is correct?

Sex hormones in humans

The diagram illustrates the human female reproductive system. In which structure does fertilisation normally take place?

Sexual reproduction in humans

In mice, the allele for black hair is dominant over the allele for brown hair. What proportion of the offspring would show brown hair if a homozygous black mouse is crossed with a heterozygous black mouse?

Monohybrid inheritance

Which table row about variation is correct?

Variation

For many centuries, humans have reared sheep because they provide wool. The flow chart illustrates how a farmer might breed sheep so that more wool is produced. Which process is shown by this flow chart?

Selection

The figures in the diagram indicate the amount of energy transferred through part of an ecosystem. How much energy is transferred from herbivores to carnivores?

Energy flow

The diagram illustrates a food web in a rainforest. How many trophic levels are displayed in this food web?

Food chains and food webs

The diagram illustrates the carbon cycle. Which labelled processes show respiration?

Nutrient cycles

Vitamin A deficiency is a serious health issue in some regions of the world and may lead to conditions including blindness. Rice can be genetically modified so that people can produce vitamin A when they eat it. $150\ \text{g}$ of this rice supplies $60\%$ of the adult recommended daily intake of vitamin A. What mass of rice does an adult require to obtain $100\%$ of the recommended daily intake of vitamin A?

Genetic modification

In the photomicrograph, a cell from an aquatic plant is shown. Which labelled structures show that it is a plant cell?

Cell structure

What characteristic of bacteria makes them useful in genetic modification?

Genetic modification

A magnified image of a cell is shown in the diagram. The magnification is $\times 360$. Line LM gives the width of the cell image. In this diagram, line LM measures $18\text{ mm}$. What is the actual width of the cell?

Size of specimens

Which factor would reduce the rate at which oxygen diffuses into cells?

Diffusion

Which molecule is able to pass through a partially permeable membrane during osmosis?

Osmosis

The diagrams illustrate particles moving across a membrane. The arrows indicate the direction of movement. Which diagram represents active transport?

Active transport

What substance is used to test food for vitamin C?

Biological molecules

What is used as a basis for classification?

Concept and uses of classification systems

Which characteristic explains the specificity of an enzyme?

Enzymes

A plant is kept in darkness until all of the starch it has stored is exhausted. It is then put in light, with black paper covering part of one green leaf. After eight hours, the leaf is tested for starch. Which diagram shows how the leaf looks after this test?

Photosynthesis

The diagram shows part of a leaf cross-section. Which row gives the correct labels?

Leaf structure

The diagrams illustrate the various kinds of human teeth. Which teeth are used for grinding food?

Physical digestion

The diagram depicts a villus. Structures P and Q take in different digestion products. Which row correctly names the products absorbed by P and Q?

Absorption

The arrows indicate how substances travel from the soil into a root hair cell. Which substances pass from the soil into the root hair cell?

Water uptake

Through which process does water leave the stomata in leaves?

Transpiration

Which row concerning the circulatory system is correct?

Circulatory systems

The graph illustrates the pressure changes occurring in the right atrium, right ventricle and left ventricle of a human heart as the muscle walls contract and relax. What is the pressure in the right ventricle when the left ventricle reaches its highest pressure?

Heart

Which function is made possible by the amino acid sequence in antibodies?

Biological molecules

What number of jointed legs does an insect possess?

Features of organisms

The table shows some of the changes that happen during breathing. Which changes happen to produce inspiration?

Gas exchange in humans

The apparatus illustrated was used to study aerobic respiration in seeds. The apparatus was kept in a dark room. All environmental conditions were held constant. What will occur in the apparatus?

Aerobic respiration

For what reason is yeast used in bread-making?

Anaerobic respiration

In the diagram, which label shows the urethra?

Excretion in humans

The diagram illustrates a reflex arc. Which label shows the motor neurone?

Coordination and response

What structures in neurones contain neurotransmitter molecules?

Coordination and response

The diagram shows a seedling growing in a dark box. Which kind of responses influence the direction in which the root and the shoot grow inside the box?

Tropic responses

What makes an MRSA infection hard to treat?

Drugs

In what sequence do the flower parts need to be traversed by the pollen tube in order to reach the egg cell nucleus during fertilisation?

Sexual reproduction in plants

Which diagram, illustrating the transfer of substances between mother and fetus, is labelled correctly?

Sexual reproduction in humans

The photomicrograph shows a cell from a species of aquatic plant. Which labelled structures show that this is a plant cell?

Cell structure

Which statement concerning the synthesis of a protein molecule inside a cell is correct?

Chromosomes, genes and proteins

The statements below refer to cell division by mitosis or meiosis in humans. 1 It creates cells that vary from one another. 2 It creates cells that are diploid. 3 It creates cells that are haploid. 4 It includes reduction division. Which statements refer to meiosis?

Meiosis

In humans, what genotype does a red-green colour-blind male have?

Chromosomes, genes and proteins

Which characteristic is present in a hydrophytic plant?

Adaptive features

Which statements are true in both natural selection and artificial selection?

Selection

The diagram illustrates a food chain. phytoplankton → zooplankton → herring → sea lion Which diagram represents a pyramid of energy for this food chain?

Energy flow

In the nitrogen cycle, which processes are labelled 1 and 2?

Nutrient cycles

Sewage that has not been treated is released by accident into a river for several weeks. What effect will this have on the number of bacteria, the oxygen concentration in the water, and the number of fish?

Pollution

There are several ways to conserve fish stocks. Which conservation method makes it so that mostly large fish are caught?

Conservation

Which part of bacteria is genetically altered to produce human insulin?

Genetic modification

The diagram represents a red blood cell. The cell’s true diameter is 7.0 micrometres. What is the magnification of this cell?

Size of specimens

Fermenters need conditions to be tightly controlled. Which condition is paired with the correct reason for controlling it?

Biotechnology

Which molecule moves through a partially permeable membrane during osmosis?

Osmosis

The graph illustrates the rate at which magnesium ions are taken up by two similar plants, X and Y. For each plant, the roots were placed in a series of solutions. Each solution had a different magnesium ion concentration. Every other condition was kept constant. What is a possible explanation for the difference in the results for the two plants?

Active transport

Which substance is used to check a food for vitamin C?

Biological molecules

Within DNA, which bases form the correct pairs?

Chromosomes, genes and proteins

What is left once an enzyme-controlled reaction has ended?

Enzymes

Five different foods were analysed for their nutrient content. The mass of each nutrient in 100 g of food was estimated. The results are displayed in Table 1.1. For an adult, the recommended daily allowance for these nutrients is: • fat - a maximum of 70 g per day • protein - 50 g per day.

Diet

A student compared how fast water is lost from leaves at two different temperatures. Every day for seven days, the student recorded the mass of one leaf at the same time. The leaf was kept at 15 ^{\circ}C. The student then repeated this using a similar-sized leaf kept at 25 ^{\circ}C. Fig. 2.1 shows some of the apparatus that was used. The results are displayed in Fig. 2.2.

Transpiration

Huntington’s disease is a hereditary disorder caused by a change in one gene. The allele for Huntington’s disease is dominant and is shown by the letter H. The allele for no Huntington’s disease is recessive and is shown by the letter h. Fig. 3.1 is a pedigree chart showing the inheritance of Huntington’s disease in one family.

Monohybrid inheritance

Fig. 4.1 presents a diagram of a bacterial cell.

Cell structure

Fig. 5.1 shows a diagram of the human breathing system.

Gas exchange in humans

Fig. 6.1 shows a diagram of part of the carbon cycle.

Nutrient cycles

The list includes some organs and glands found in the human body: adrenal, ovary, prostate, pancreas, salivary, testis.

Hormones

Fig. 1.1 gives a simplified representation of the human circulatory system.

Blood vessels

A learner examined how starch is digested. Fig. 2.1 shows the apparatus she used. Dialysis tubing is used as a model of a cell membrane. The dialysis tubing material lets small molecules pass through it, but not larger molecules. Test-tubes A and B were arranged as shown in Fig. 2.1 and kept in a water-bath at 37 ^{\circ}C for 30 minutes. The liquid outside the dialysis tubing in test-tubes A and B was checked with Benedict’s solution at 0 minutes and again after 30 minutes. Table 2.1 gives the results.

Chemical digestion

Complete every part of Fig. 3.1.

Sexual reproduction in plants

Fig. 4.1 shows a photograph of a tree that has been girdled. Girdling means removing a complete ring of bark and phloem all the way round the trunk.

Translocation

The eye functions as a sense organ and is a component of the nervous system.

Sense organs

Golden rice is a genetically modified variety of rice that contains the nutrient beta-carotene. Fig. 6.1 illustrates the genetic modification procedure used to make golden rice.

Genetic modification