STAAR Biology Category 2 Review

Front

What is a nucleotide?

Back

A nucleotide is the basic building block of nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base.

Front

What are the components of a DNA nucleotide?

Back

A DNA nucleotide consists of deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine, thymine, cytosine, or guanine.

Front

What are the components of an RNA nucleotide?

Back

An RNA nucleotide consists of ribose sugar, a phosphate group, and one of four nitrogenous bases: adenine, uracil, cytosine, or guanine.

Front

What is the difference between ribose and deoxyribose?

Back

Ribose is a five-carbon sugar found in RNA, while deoxyribose is a five-carbon sugar found in DNA, lacking one oxygen atom.

Front

What is codominance in genetics?

Back

Codominance is a type of non-Mendelian inheritance where both alleles in a heterozygote are fully expressed, resulting in offspring with a phenotype that is neither dominant nor recessive.

Front

What is incomplete dominance?

Back

Incomplete dominance is a form of inheritance where the phenotype of a heterozygote is intermediate between the phenotypes of the two homozygotes.

Front

What is polygenic inheritance?

Back

Polygenic inheritance is a type of inheritance where multiple genes influence a single trait, resulting in a continuous range of phenotypes.

Front

What is the difference between dominant and recessive traits?

Back

Dominant traits are expressed in the phenotype even when only one copy of the allele is present, while recessive traits are only expressed when two copies of the allele are present.

Front

What does it mean for a trait to 'skip a generation'?

Back

A trait 'skips a generation' when it is not expressed in one generation but reappears in the next, often due to recessive inheritance.

Front

How do muscle cells and nerve cells have the same DNA but different functions?

Back

Muscle cells and nerve cells have the same DNA, but they express different sets of genes, leading to the production of different proteins that determine their functions.