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WorksheetsIGCSE 18.1-2
Total questions: 22
Worksheet time: 11mins
Which statement best describes variation in a population?
Variation decreases the chance of survival.
Variation is differences between individuals of the same species.
Variation only applies to phenotypic features.
There is no variation within a species.
What type of variation in pea plants did Mendel study in his experiments?
Continuous variation in height
Discontinuous variation in flower color
Continuous variation in seed shape
Discontinuous variation in seed color
Which factor does NOT influence continuous variation?
Environment
Genes
Number of legs
Diet
Fur color in mice is an example of:
Continuous variation
Discontinuous variation
Mutation
Environmental variation
Compared to discontinuous variation, continuous variation:
Has more limited phenotypes
Is influenced only by the environment
Produces a range of phenotypes
Is caused only by genetic differences
Which statement about variation in a population is FALSE?
Variation originates from mutation.
Variation can be inherited.
Variation only applies to visible features.
Variation allows for natural selection.
What is the original source of genetic variation in a population?
Meiosis
Fertilization
Mutation
Hybridization
How does random mating influence variation?
It only produces identical offspring.
It limits the combinations of alleles.
It increases the genetic combinations.
It eliminates recessive alleles.
What is the main advantage of sexual reproduction regarding variation?
It requires less energy.
It combines alleles from two parents.
It involves fewer differences.
It does not require fertilization.
Which condition would likely result in a population having limited genetic variation?
High mutation rate
Large population size
Random mating
Genetic drift
Why does mutation play a key role in evolution?
It eliminates harmful alleles.
It produces completely new phenotypes.
It is the ultimate source of heritable variation.
It limits discontinuous variation.
What term describes features that improve an organism's fitness?
Neutral variations
Useless variations
Harmful variations
Adaptive features
What enables a desert plant to limit water loss?
Wide, flat leaves
Spines instead of leaves
Short life cycle
Bright flower colors
Cacti and succulents store water in which structures?
Flowers
Stems
Roots
Stomata
How does mimicry help some insects avoid predators?
By using cryptic coloration
By looking like poisonous species
By producing foul odors
By having protective shells
What adaptive feature allows pollination of wind-pollinated plants?
Bright flowers
Lots of pollen
Strong scents
Nectar guides
What was the evidence Darwin used to develop his theory of natural selection?
Fossil evidence showing relationships
Molecular data on DNA sequences
Observed inheritance patterns
Adaptations of organisms to the environment
Individuals with a CCR5 gene deletion are resistant to HIV infection because:
The deletion prevents HIV from entering and infecting T cells.
The deletion causes overproduction of antibodies against HIV.
The deletion prevents fusion of the viral envelope with host cells.
The deletion blocks HIV from integrating its genes into host DNA.
What conditions likely contributed to the CCR5 deletion becoming more common?
Widespread vaccination against HIV
High rates of HIV infection and death
Use of antiretroviral drugs to treat HIV
Public health measures to block HIV transmission
How did the CCR5 deletion mutation originate?
It was induced by a vaccine.
It naturally arose and provided a selective advantage.
It was intentionally engineered to resist HIV.
It spread through gene flow from another species.
Mice living on dark lava rocks are more likely to have mutations leading to dark fur because:
The dark fur helps hide them from predators.
The habitat induces new mutations.
Dark fur mice migrate there from other areas.
Mating is non-random among the mice.
What evidence suggests the mouse fur color variation is adaptive?
The mutation rate on the lava rocks is higher.
Mice breed selectively based on fur color.
Fur color matches the background environment.
Migration introduces new mutations.
