Alelo recesivo

The video tutorial explains the concept of alleles, focusing on recessive alleles. It describes how recessive alleles are expressed only when two copies are present, using the example of blue eyes in humans. The tutorial contrasts this with dominant alleles, such as brown eyes, which are expressed even if only one copy is present.

What is an allele?

• A type of cell

• A version of a gene

• A chromosome

• A protein

When is a recessive allele expressed?

• When it is on the Y chromosome

• When only one copy is present

• When it is dominant

• When two copies are present

Which of the following is true about recessive alleles?

• They are expressed only when two copies are present

• They are expressed only in males

• They are never expressed

• They are always expressed

In humans, what is the allele for blue eyes considered?

• Dominant

• Recessive

• Co-dominant

• Incomplete dominant

What eye color will a person have if they inherit a brown allele and a blue allele?

• Blue

• Green

• Brown

• Hazel