Oct/Nov 2023

A list of processes performed by living organisms is given below. 1 egestion 2 excretion 3 reproduction 4 respiration Which of these processes are performed by every living organism?

Characteristics of living organisms

The graph illustrates how temperature affects the activity of four different enzymes. Which conclusion drawn from the data in the graph is correct?

Enzymes

What colour does hydrogencarbonate indicator become when the carbon dioxide concentration rises?

Photosynthesis

The diagram shows a test-tube at the beginning and at the end of an enzyme experiment. By the end of the experiment, the contents of the test-tube include glycerol. Which row correctly names the enzyme and the substrate on which it acts?

Enzymes

The diagram illustrates the teeth in the human lower jaw. Which tooth is a molar?

Digestive system

What does the term chemical digestion mean?

Chemical digestion

Which food provides a good source of vitamin C?

Diet

What does transpiration describe?

Transpiration

Several parts of a plant are named. What route does water follow through the plant?

Transpiration

Some components of the human circulatory system are given. Which structures contain valves that guarantee blood flows in only one direction?

Circulatory systems

Which kind of cells make antibodies?

Diseases and immunity

The scientific name of humans is $\text{Homo sapiens}$. To what does $\text{Homo}$ refer?

Concept and uses of classification systems

State one example of a transmissible disease.

Diseases and immunity

Which table correctly presents the difference in composition between inspired air and expired air?

Gas exchange in humans

Where does gas exchange occur in humans?

Gas exchange in humans

The following three statements refer to anaerobic respiration. 1. In humans, the product is lactic acid. 2. In yeast, the product is lactic acid. 3. It gives more energy per glucose molecule than aerobic respiration. Which statements are correct?

Anaerobic respiration

Which organ is responsible for producing insulin?

Hormones

The diagram illustrates the human excretory system. Which labelled structure represents the urethra?

Excretion in humans

The diagrams illustrate three kinds of neurones. Which order shows the direction in which impulses travel in a reflex action?

Coordination and response

Which section of the eye senses red light?

Sense organs

The diagram illustrates a human sperm cell. Which structure breaks down the egg cell membrane?

Sexual reproduction in humans

Which illnesses can antibiotics be used to treat successfully?

Drugs

Which row gives the correct arthropod classification?

Concept and uses of classification systems

Some species of plant reproduce by forming bulbs. The diagram shows a bulb. A single parent plant produces the bulb, and this bulb develops into a new plant. Which statement about the new plant is correct?

Asexual reproduction

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

Sexual reproduction in humans

What can be used to lower the transmission of HIV?

Sexually transmitted infections

Which of the statements about human sex chromosomes is correct?

Chromosomes, genes and proteins

In pea plants, seed colour is determined by a single gene. The allele for yellow seed colour, $Y$, is dominant, whereas the allele for green seed colour, $y$, is recessive. What are the possible genotypes of a pea seed that is yellow?

Monohybrid inheritance

The graph displays the heights of the students in a class. Which statement about these data is correct?

Variation

Which process lowers the amount of carbon dioxide in the atmosphere?

Photosynthesis

It is estimated that $90\%$ of the energy passing through living organisms in a food chain is lost from one trophic level to the next. The producers in a food chain have $1000$ units of energy. How many units of energy will reach the quaternary consumers in the food chain?

Energy flow

What may rise as a consequence of deforestation?

Habitat destruction

The diagram indicates where a farmer’s field is located beside a river. The farmer uses chemical fertilisers that run off into the river, polluting it. Large amounts of the chemical fertiliser lead to greater growth of aquatic plants. At which point is aquatic plant growth least influenced by fertilisers?

Pollution

Within a mesophyll cell, where can chloroplasts be located?

Leaf structure

The diagram presents a food web. Which food chain shows the correct direction of energy transfer through the web?

Food chains and food webs

The cell in the diagram has been enlarged 3000 times. The diagram is 21 mm wide. What is the cell’s true diameter?

Size of specimens

The diagrams illustrate how a cell looks under a microscope at the beginning of an experiment and after being kept in a dilute solution of salts for 5 minutes. Which statement explains the change?

Osmosis

What leads to oxygen diffusing into a plant cell?

Diffusion

What colour change does Benedict’s solution undergo when it is heated with a reducing sugar?

Biological molecules

The diagram illustrates the digestive system. Which part absorbs the greatest amount of water?

Absorption

Which of the following processes occur in all living organisms? 1 digestion 2 respiration 3 excretion

Characteristics of living organisms

Which changes could make an enzyme denature? 1 change in pH 2 change in temperature 3 change in substrate concentration

Enzymes

What leaf features allow more carbon dioxide to diffuse into the palisade cells for photosynthesis?

Leaf structure

The diagram shows a cell with clusters of bacteria along its outer edge. The bacteria have moved towards regions with a high oxygen concentration. Which process in the cell causes the bacteria to gather into these clusters?

Aerobic respiration

The diagram shows the teeth in the lower jaw of a human. Which tooth is a premolar?

Physical digestion

Some medicines are formed into tablets and then covered with a substance that is similar to starch. This covering shields the medicine from the action of gastric juice. Which enzyme breaks down the covering, and what is formed as a result of this?

Chemical digestion

In which section of the alimentary canal are most nutrients taken into the blood?

Absorption

From which region of a leaf does most water evaporate during transpiration?

Transpiration

The photograph shows a transverse section of a sunflower stem. What is the tissue labelled Z called, and what is its function?

Xylem and phloem

What feature makes blood flow in only one direction in the human circulatory system?

Heart

In which row is the blood component matched correctly with its function?

Blood

In the binomial system, the Arctic fox is named Vulpes lagopus. Which row is correct?

Concept and uses of classification systems

Which statement identifies a transmissible disease?

Diseases and immunity

How does the composition of expired air compare with that of inspired air?

Gas exchange in humans

The diagram illustrates the human respiratory system. Which structures are labelled?

Gas exchange in humans

Yeast cells are able to change glucose into alcohol and carbon dioxide. Which statement about this process is accurate?

Anaerobic respiration

In an experiment designed to investigate anaerobic respiration, two bottles are arranged in a warm room, as shown. What would happen to each balloon after one day?

Anaerobic respiration

Which row identifies an organ and the substance that it excretes?

Excretion in humans

The diagram illustrates a reflex arc in a human nervous system. The person’s finger has just touched a sharp object. Which part is the motor neurone?

Coordination and response

Which lines on the graphs display the effects of adrenaline on pupil diameter and heart rate?

Hormones

Which of the following statements about tropisms in plants are correct?

Tropic responses

How is a substance described if it is taken into the body and changes or influences chemical reactions in the body?

Drugs

The diagrams illustrate four distinct kinds of arthropod. Which organism has been labelled with its correct arthropod group?

Concept and uses of classification systems

Which row shows the correct statement about asexual reproduction?

Asexual reproduction

The diagram illustrates several stages in reproduction. Which letter correctly names the structure or process?

Sexual reproduction

The diagram displays half of a flower. Which structure makes pollen?

Sexual reproduction in plants

Two parents have genotypes Bb and bb for a particular feature. What is the chance that their offspring will be homozygous recessive for this feature?

Monohybrid inheritance

A genetic cross involving two organisms can be represented as $Tt \times Tt$. What does $T$ stand for?

Monohybrid inheritance

Several phenotypes are given. Which of these phenotypes are examples of continuous variation?

Variation

A food chain is shown. lettuce plant $\rightarrow$ slug $\rightarrow$ hedgehog Through which process is energy passed from the lettuce plant to the slug?

Food chains and food webs

One bush provides food for a very large population of greenfly. The greenfly are eaten by several ladybirds. A bird eats the ladybirds. Which diagram represents the pyramid of numbers for this food chain?

Food chains and food webs

Scientists investigated how wheat plants absorb potassium ions from chemical fertilisers. The results are shown. What difference is there in the uptake of potassium ions $360$ days after planting, compared with $30$ days after planting?

Xylem and phloem

A student carried out an investigation into gas exchange with the apparatus shown. After breathing in and out through the mouthpiece for one minute, what would the limewater look like in tube X and tube Y?

Gas exchange in humans

Which features are present in every plant cell?

Cell structure

The diagram illustrates the transfer of energy within an ecosystem. Which row correctly fills boxes $1$, $2$ and $3$?

Food chains and food webs

An egg has a diameter of 6.5 cm. A student makes a drawing of the egg. In the drawing, the egg’s diameter measures 19.5 cm. What magnification has been used for the drawing?

Size of specimens

The diagram illustrates an experiment designed to investigate osmosis in living cells. What happens to the volumes of water and sugar solution after 12 hours?

Osmosis

Which process allows oxygen to diffuse from an alveolus in the lung into a blood capillary?

Gas exchange in humans

Which row shows the chemical elements present in proteins?

Biological molecules

The table lists some large biological molecules and some smaller biological molecules. Which rows correctly match each large molecule with the smaller molecules that join together to form it?

Biological molecules

What characteristics are shared by all living organisms?

Characteristics of living organisms

The diagrams show an enzyme together with its substrate. Which region of the enzyme molecule acts as the active site for this substrate?

Enzymes

What is one use of the carbohydrates produced by photosynthesis?

Photosynthesis

The diagram illustrates an experiment that examines how light intensity affects an aquatic plant. In both test-tube P and test-tube Q, photosynthesis took place. The two test-tubes were maintained at the same temperature. Test-tube P produced $12$ bubbles per minute. Which number of bubbles is most likely to be produced in one minute in test-tube Q?

Photosynthesis

Which human teeth are used for biting and cutting up food?

Physical digestion

The diagram shows part of the human digestive system. Which organ is responsible for producing hydrochloric acid?

Digestive system

Which component of a balanced diet is lacking if a person develops rickets?

Diet

Through which process does a leaf lose water vapour?

Transpiration

The route followed by water as it moves through a plant is shown. root hair cells $\rightarrow$ root cortex cells $\rightarrow$ Z $\rightarrow$ mesophyll cells Which section of the pathway does Z represent?

Xylem and phloem

Which of the following statements about the human circulatory system is correct?

Circulatory systems

What characteristics do arteries have?

Blood vessels

According to the binomial system, the scientific name of a lion is Panthera leo. Which statement is correct?

Concept and uses of classification systems

What are organisms that cause disease?

Diseases and immunity

Which row shows the composition of exhaled air from a healthy person?

Gas exchange in humans

What route does carbon dioxide follow as it leaves the lungs?

Gas exchange in humans

Which statement concerning anaerobic respiration is correct?

Anaerobic respiration

What term is used for a ball of cells that attaches itself to the lining of the uterus?

Sexual reproduction in humans

The diagram illustrates parts of the human body that take part in excretion. What are the labelled parts?

Excretion in humans

The diagram illustrates a reflex action as a person makes contact with a hot object and withdraws their hand. hot object contacted $\rightarrow$ skin of hand E $\rightarrow$ neurone F $\rightarrow$ relay neurone $\rightarrow$ neurone G $\rightarrow$ arm muscle H $\rightarrow$ hand pulled away Which letter indicates a structure correctly?

Coordination and response

The diagram illustrates a cross-section of a human eye. Which structure alters its shape in response to adrenaline?

Sense organs

Give one example of a population.

Populations

Which of the following statements about antibiotics is correct?

Drugs

Which characteristic would classify organisms as members of the crustacean group of arthropods?

Features of organisms

When a pea plant with genotype $YY$ is crossed with a pea plant with genotype $yy$, what possible genotypes can the offspring have?

Monohybrid inheritance

Which graph illustrates the effect of temperature on the rate of respiration in yeast?

Anaerobic respiration

What is the accurate description of asexual reproduction?

Asexual reproduction

The diagram illustrates the reproductive organs of a human female. In which part does fertilisation usually take place?

Sexual reproduction in humans

A section of a genetic diagram about sex inheritance in humans is shown below. The sex chromosomes in two gametes are indicated. Identify the sex chromosomes in gametes 1 and 2.

Chromosomes, genes and proteins

Tusks are modified teeth. In one region of the world, most elephants were formerly born with tusks. During the past 50 years, a greater number of female elephants have been born without tusks. These elephants are producing offspring that also lack tusks. Which kinds of variation are shown by this example?

Variation

The diagrams illustrate pyramids of numbers and biomass. Which of the pyramids might be pyramids of biomass?

Food chains and food webs

Which process passes energy from the first trophic level to the second trophic level in a food chain?

Food chains and food webs

The diagram illustrates a section of the carbon cycle. Which arrow shows respiration?

Nutrient cycles

Why do bacteria play an important role in biotechnology and genetic modification?

Biotechnology and genetic modification

The diagram illustrates the structure of a palisade cell from a leaf. Which structure contains chlorophyll?

Leaf structure

Why are genes inserted into bacterial cells?

Genetic modification

A bacterial cell appears to have a length of $40\,\text{mm}$ after being enlarged by $\times 20\,000$. What is the real length of the bacterial cell?

Size of specimens

Which diagram illustrates the look of a plant cell after it has been put into pure water?

Osmosis

What would cause the rate of diffusion into a cell to decrease?

Diffusion

Which row identifies the chemical elements present in fats?

Biological molecules

Glycogen is a giant molecule formed from smaller units. Which smaller molecules are used to make glycogen?

Biological molecules