Gender is controlled in humans by the X and Y chromosomes. Genetic screening involves testing people or groups of people for the presence of a particular allele or other genetic abnormality.
Why does a person need to have two copies of the cystic fibrosis allele to have cystic fibrosis?
The allele is a carrier.
The allele is recessive.
The allele is dominant.
Which statement about chromosomes and human gender is correct?
Males are XX.
Females are XY.
Males are XY.
During fertilisation what are the chances of a male zygote being produced?
Which sex chromosome contains more genes because it is larger?
Both are equal.
Which gender has more haemophilia sufferers?
Individuals with Down syndrome have how many chromosomes?
What liquid is tested during amniocentesis?