T2 Midterm Review

Front

What does it mean to be homozygous?

Back

Having two of the same alleles for a trait, such as TT or tt.

Front

What does it mean to be heterozygous?

Back

Having two different alleles for a trait, such as Ll.

Front

What is a dominant allele?

Back

An allele that expresses its trait even when paired with a different allele.

Front

What is a recessive allele?

Back

An allele that only expresses its trait when paired with another recessive allele.

Front

What does a filled square represent in a pedigree chart?

Back

An affected male.

Front

What does a filled circle represent in a pedigree chart?

Back

An affected female.

Front

What could cause a species to go extinct?

Back

Drastic environmental changes that no one can adapt to.

Front

What is the significance of the rock layer containing the newest fossils?

Back

It indicates the most recent geological time period.

Front

What is the difference between homozygous dominant and homozygous recessive?

Back

Homozygous dominant has two dominant alleles (e.g., LL), while homozygous recessive has two recessive alleles (e.g., ll).

Front

What is natural selection?

Back

The process where organisms better adapted to their environment tend to survive and produce more offspring.