Sex Linkage (Leaving Cert Biology): Quizzes
📚Quizzes
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12 questions from this quiz
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Practise the questions
12 questions from this quiz
What is sex linkage?
What is sex linkage?
When a gene is on a sex chromosome
What sex chromosomes do females have?
What sex chromosomes do females have?
XX
What sex chromosomes do males have?
What sex chromosomes do males have?
XY
Which trait is an example of sex linkage in humans?
Which trait is an example of sex linkage in humans?
Red-green colour blindness
Haemophilia is a sex-linked trait. What does it affect?
Haemophilia is a sex-linked trait. What does it affect?
Ability to form blood clots properly
Why are sex-linked traits more common in males?
Why are sex-linked traits more common in males?
Males need only one recessive gene
How many recessive genes do females need to express a sex-linked trait?
How many recessive genes do females need to express a sex-linked trait?
Two (one on each X chromosome)
What is a carrier female for a sex-linked trait?
What is a carrier female for a sex-linked trait?
Heterozygous female who doesn't express it
What is the genotype of a colour blind male?
What is the genotype of a colour blind male?
Xn Y
What is the genotype of a carrier female for colour blindness?
What is the genotype of a carrier female for colour blindness?
XN Xn
Which chromosome contains most sex-linked genes?
Which chromosome contains most sex-linked genes?
X chromosome
Cross: carrier female (XN Xn) × normal male (XN Y). What % of offspring are colour blind males?
Cross: carrier female (XN Xn) × normal male (XN Y). What % of offspring are colour blind males?
25%