Variation and Selection
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Variation and mutation
SubtopicVariation and mutation under Variation and Selection for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
Which type of reproduction leads to more variation in the offspring?
A.Asexual reproduction
B.Sexual reproduction
C.Binary fission
D.Budding
- 2.
Which of these is a likely cause of a mutation?
A.Gamma rays
B.Vitamin C
C.Nitrogen gas
D.Pure water
- 3.
A gene mutation is a change in the base sequence of:
A.Protein
B.DNA
C.Carbohydrate
D.Lipid
- 4.
What is the relationship between genotype and phenotype?
A.Genotype is determined by the phenotype
B.Phenotype is the expression of the genotype in a specific environment
C.They are the same thing
D.Environment determines the genotype
- 5.
Which of the following factors is a source of new alleles in a population's gene pool?
A.Inbreeding
B.Meiosis
C.Gene mutation
D.Random mating
- 6.
Which of these statements about variation is correct?
A.All variation is caused by mutations
B.Variation only exists in species that reproduce sexually
C.Variation is the differences between individuals of the same species
D.Variation always results in the death of the organism
- 7.
Which of the following is an example of a phenotypic variation caused by an interaction of genetics and environment?
A.A person's ABO blood group
B.A person's final adult height
C.The presence of a scar on the arm
D.A person's natural eye color
- 8.
A single point mutation occurs in a germ-line cell during DNA replication, just before the cell enters meiosis. This mutation affects only one of the two sister chromatids of a single chromosome. According to the process shown in the diagram, what is the probability that any single gamete produced from this specific meiosis will carry the mutated allele, and what is its biological significance?
A.; it ensures that the mutation will be passed on to the majority of the offspring in the next generation.
B.; it introduces a new allele into the gene pool, increasing genetic variation for natural selection.
C.; it results in a chromosomal mutation that changes the species' diploid number ().
D.; it causes the variation for that specific trait in the population to become continuous.
- 9.
If a mutagen causes a Cytosine to be replaced by a Guanine () in a DNA sequence, this is specifically known as a:
A.Transition substitution
B.Transversion substitution
C.Translocation
D.Inversion
- 10.
Which of these processes decreases the variation within a population's gene pool?
A.Mutation
B.Sexual reproduction
C.Natural selection
D.Gene flow
Download the worksheet for Variation and Selection - Variation and mutation to practice offline. It includes additional chapter-level practice questions.
Adaptive features
SubtopicAdaptive features under Variation and Selection for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
Why do some deep-sea fish have the ability to produce their own light (bioluminescence)?
A.To stay warm in the cold water
B.To attract prey or mates in the total darkness
C.To help them swim faster
D.To see through the muddy water
- 2.
Which of these features helps a frog survive in a habitat that occasionally dries up?
A.The ability to burrow into the mud and become inactive (estivation)
B.Having bright green skin
C.Laying thousands of eggs at a time
D.Having long back legs for jumping
- 3.
What adaptation allows some seeds, like those of a dandelion, to be dispersed over long distances?
A.A heavy, protective shell
B.A tasty fruit coating
C.Lightweight structures like 'parachutes' for wind travel
D.Hooks that attach to animal fur
- 4.
How does the ability to 'play dead' help an opossum survive?
A.It helps it conserve energy
B.It discourages predators that prefer to hunt live prey
C.It allows it to hide from the sun
D.It attracts smaller animals that the opossum eats
- 5.
Which statement about natural selection is correct?
A.It leads to individuals becoming perfectly adapted to all environments
B.It causes the frequency of advantageous alleles to increase over time
C.It occurs only when there is a lack of competition for resources
D.It results in new species being formed within a single generation
- 6.
Why do some plants in the understory of a tropical rainforest have very large, broad leaves?
A.To maximize the loss of excess water through transpiration
B.To capture as much of the limited sunlight as possible
C.To prevent the leaves from being damaged by heavy rain
D.To provide a large surface for gas exchange in dry air
- 7.
The mountain hare changes its coat color from brown in summer to white in winter. This is an example of:
A.A permanent mutation
B.A seasonal structural adaptation
C.The inheritance of acquired traits
D.A behavioral adaptation
- 8.
What is the primary benefit of 'counter-illumination' (bioluminescence on the underside) in some marine animals?
A.To light up the sea floor to find prey.
B.To attract mates in the dark water.
C.To mask the animal's silhouette against the faint light from the surface, making it invisible to predators below.
D.To communicate with other members of the same species.
- 9.
In the context of evolution, what is the 'selective pressure' acting on a population of insects that are being sprayed with a new pesticide?
A.The mutation that makes some insects resistant.
B.The chemical pesticide itself, which determines which individuals survive.
C.The food source that the insects are eating.
D.The reproductive rate of the insects.
- 10.
Which of these features in a polar bear is a 'physiological' adaptation rather than a structural one?
A.A thick layer of blubber under the skin.
B.White fur for camouflage against the snow.
C.The ability to slow down its metabolism during periods of food scarcity.
D.Wide paws that act like snowshoes.
Download the worksheet for Variation and Selection - Adaptive features to practice offline. It includes additional chapter-level practice questions.
Selection (Natural and Artificial)
SubtopicSelection (Natural and Artificial) under Variation and Selection for Grade 11 IGCSE.
Preview questions (no answers)
- 1.
Which of these is an example of artificial selection in dogs?
A.Wolves hunting in packs
B.Breeding Labradors for their friendly nature
C.Wild dogs developing thick fur for winter
D.Puppies growing larger as they age
- 2.
How do advantageous alleles get passed on to the next generation?
A.By breathing on other individuals
B.Through reproduction
C.Through the soil
D.By eating the same food
- 3.
Why are some organisms in a population more likely to survive than others in the wild?
A.They have been trained by their parents
B.They possess alleles that give them a survival advantage
C.They choose to be faster or stronger
D.They are the oldest members of the group
- 4.
Which of these describes an adaptation to a cold environment?
A.Large ears to lose heat
B.A thick layer of blubber or fat
C.Thin skin to absorb sunlight
D.Short roots to find water
- 5.
What is the main reason why humans perform selective breeding on livestock like sheep?
A.To increase the sheep's ability to survive in the wild
B.To produce specific products like wool or meat more efficiently
C.To observe how natural selection works in real time
D.To prevent the sheep from evolving into new species
- 6.
Which of the following correctly describes the interaction between genes and the environment in natural selection?
A.The environment creates new genes to help the organism survive
B.Genes determine traits, and the environment determines if those traits are successful
C.The environment and genes have no relationship in the process of selection
D.Organisms change their genes based on what the environment needs
- 7.
In a population of fish, some are better at escaping nets. Over time, the fish become smaller and more agile. What was the selection pressure?
A.The temperature of the water
B.The presence of fishing nets
C.A lack of food in the ocean
D.Competition for mates
- 8.
Which of the following is the best example of 'co-evolution' driven by natural selection?
A.A farmer selecting for both larger corn kernels and sweeter taste.
B.A species of orchid developing a shape that perfectly fits the beak of a specific hummingbird species that pollinates it.
C.A population of bacteria developing resistance to three different antibiotics at once.
D.A breed of dog being selected for both thick fur and a friendly temperament.
- 9.
In the process of selective breeding, why might a breeder choose to cross two distantly related individuals of the same species?
A.To decrease the mutation rate in the offspring.
B.To increase the chance of producing homozygous recessive offspring.
C.To introduce new alleles and reduce the risk of inbreeding depression.
D.To ensure the offspring are exactly like one of the parents.
- 10.
What happens during a 'selective sweep' when a highly beneficial mutation appears in a population?
A.The mutation is immediately deleted from the gene pool.
B.The beneficial allele increases in frequency, and nearby DNA sequences on the same chromosome also increase in frequency.
C.The entire population dies out because the mutation is too powerful.
D.Natural selection stops occurring because the 'perfect' individual has been found.
Download the worksheet for Variation and Selection - Selection (Natural and Artificial) to practice offline. It includes additional chapter-level practice questions.