Unit 4 Flashcardizz

Front

What is the genotype of a homozygous dominant organism?

Back

BB

Front

What is the genotype of a heterozygous organism?

Back

Bb

Front

What is the phenotype of an organism?

Back

The physical trait of an organism.

Front

What does genotype refer to?

Back

The possible combination of alleles in a gene.

Front

What type of chromosomal abnormality is associated with Down Syndrome?

Back

Trisomy 21.

Front

In a Punnett Square, what does each box represent?

Back

A possible genotype of the offspring.

Front

What is the expected genotype ratio from a cross between BB and Bb?

Back

50% BB and 50% Bb.

Front

What is the expected phenotype ratio from a cross between two heterozygous organisms (Bb x Bb) for a dominant trait?

Back

75% dominant phenotype and 25% recessive phenotype.

Front

What is the definition of a dominant allele?

Back

An allele that expresses its trait even in the presence of a recessive allele.

Front

What is the definition of a recessive allele?

Back

An allele that expresses its trait only when two copies are present.