1What is a gene?
A section of DNA coding for a protein.
2What is an allele?
An alternative form of a gene.
3What is a locus?
The position of a gene on a chromosome.
4What is a genotype?
The genetic makeup of an organism.
5What is a phenotype?
The observable characteristics of an organism.
6What is a dominant allele?
An allele expressed when present.
7What is a recessive allele?
An allele only expressed when homozygous.
8What is homozygous?
Having two identical alleles.
9What is heterozygous?
Having two different alleles.
10What is codominance?
Both alleles are fully expressed.
11What is incomplete dominance?
A heterozygote shows an intermediate phenotype.
12What is a monohybrid cross?
A genetic cross involving one gene.
13What is a dihybrid cross?
A genetic cross involving two genes.
14What is an F1 generation?
The first offspring generation.
15What is an F2 generation?
The offspring of the F1 generation.
16What is a sex-linked gene?
A gene located on a sex chromosome.
17Which chromosome usually carries sex-linked genes?
The X chromosome.
18Why are males more affected by sex-linked disorders?
They only have one X chromosome.
19What is a carrier?
A heterozygous individual carrying a recessive allele.
20What is a mutation?
A change in the DNA base sequence.
21What causes genetic variation?
Mutation, meiosis, and random fertilisation.
22What is variation?
Differences between individuals of a species.
23What is discontinuous variation?
Variation with distinct categories.
24What is continuous variation?
Variation showing a range of values.
25What is polygenic inheritance?
A characteristic controlled by many genes.
26What is autosomal inheritance?
Inheritance involving non-sex chromosomes.
27What is a pedigree chart?
A diagram showing inheritance across generations.
28What is a test cross?
Crossing with a homozygous recessive organism to determine genotype.
29What is genetic screening?
Testing for genetic disorders or carrier status.
30What is selective breeding?
Choosing organisms with desired traits to reproduce.
31What is a chromosome?
A DNA molecule carrying genes.
32How many chromosomes do humans have?
46 chromosomes.
33What is a haploid cell?
A cell with one set of chromosomes.
34What is a diploid cell?
A cell with two sets of chromosomes.