Question 1
What is meant by the genome of an organism?
-
Its entire genetic material
-
All proteins made by one cell
-
Only the genes on one chromosome
-
All traits caused only by environment
Question 2
How is DNA best described?
-
As a polymer made from nucleotide units
-
As a lipid that stores long-term energy
-
As a protein that catalyses respiration
-
As a carbohydrate in cell walls
Question 3
Which molecule carries genetic information in most organisms?
-
DNA
-
Glycogen
-
Haemoglobin
-
Cellulose
Question 4
What is a gene?
-
A section of DNA that codes for a sequence of amino acids
-
A whole chromosome
-
A type of cell organelle
-
A process that occurs during respiration
Question 5
Why can different versions of the same gene produce different phenotypes?
-
Different alleles can code for proteins with different effects
-
Alleles always make identical proteins
-
Genes are not involved in phenotype
-
Proteins are inherited only from the father
Question 6
Most human body cells contain how many chromosomes?
-
46
-
23
-
92
-
44
Question 7
In humans, what are gametes?
-
Haploid cells with 23 chromosomes
-
Diploid cells with 46 chromosomes
-
Body cells formed by mitosis
-
Cells that cannot carry genes
Question 8
Why does sexual reproduction increase genetic variation?
-
Offspring inherit a mix of alleles from two parents
-
Offspring are genetic clones of one parent
-
No mutation can occur in sexual reproduction
-
All gametes are genetically identical
Question 9
Why does asexual reproduction usually produce genetically identical offspring?
-
There is one parent and no fusion of gametes
-
Two parents each contribute half the genes
-
Chromosome number doubles in every generation
-
Genes are removed before cell division
Question 10
What does a dominant allele do?
-
Is expressed in the phenotype when only one copy is present
-
Is only expressed when two copies are present
-
Always produces a harmful phenotype
-
Is found only in male gametes
Question 11
Why can two brown-eyed parents have a blue-eyed child?
-
Both parents can carry a recessive blue-eye allele
-
Eye colour is controlled only by environment
-
Dominant alleles never pass to offspring
-
Blue eye alleles are not inherited
Question 12
In humans, which combination usually gives a male biological sex?
-
XY
-
XX
-
YY
-
XO
Question 13
What is selective breeding?
-
Choosing parents with desired traits so offspring are more likely to show them
-
Changing genes directly in a laboratory
-
Cloning an adult using embryo transfer
-
Allowing only natural selection with no human choice
Question 14
What is a common risk of selective breeding?
-
Reduced genetic variation and increased chance of inherited defects
-
Guaranteed resistance to all diseases
-
Instant formation of new species
-
Removal of all recessive alleles
Question 15
What does genetic engineering involve?
-
Inserting a gene from one organism into another organism's DNA
-
Crossing two organisms naturally to mix all genes
-
Growing only cloned plants from cuttings
-
Using fertilisers to change inherited characteristics
Question 16
Why might genetically engineered crop plants be useful?
-
They can be made resistant to some pests or herbicides
-
They no longer need photosynthesis
-
They can survive without water permanently
-
They remove all need for selective breeding
Question 17
What is natural selection?
-
Better-adapted individuals survive and reproduce more successfully
-
All individuals survive and reproduce equally
-
Organisms choose new genes when conditions change
-
Evolution happens without inheritance
Question 18
How do new resistant strains of bacteria evolve?
-
Mutations create variation, and resistant bacteria survive antibiotic treatment
-
Bacteria intentionally develop resistance when exposed
-
Antibiotics cause all bacteria to mutate identically
-
Resistant bacteria always grow slower and disappear
Question 19
What do fossils provide evidence for?
-
How organisms and species have changed over time
-
Exact DNA sequences of all extinct organisms
-
Daily weather in ancient ecosystems
-
Future mutations in current species
Question 20
How can isolation of populations contribute to speciation?
-
Different environments select different traits until populations can no longer interbreed
-
Isolation prevents any evolution from occurring
-
Isolation makes all populations genetically identical
-
Isolation immediately doubles chromosome number in every generation