Genetics Review

Which statement is an accurate description of genes?

• Proteins are made of genes and code for DNA

• Genes are made of proteins that code for nitrogen bases

• DNA is made of carbohydrates that code for genes.

• Genes are made of DNA and code for proteins.

A woman changes her hair color to red; however, her children will not inherit this red hair color because the woman does not have

• genes for red hair in her skin

• genes for red hair in her sex cells

• proteins for red hair in her placenta

• proteins for red hair in her egg cells

The region labeled A is made up of a section of

• a protein that becomes an enzyme

• DNA that may direct protein synthesis

• a carbohydrate made from amino acids

• glucose that may be copied to make DNA

The molecule DNA contains the four bases listed below.

A – adenine

C – cytosine

G – guanine

T – thymine

Which base pairings normally occur during DNA replication?

• Guanine pairs with cytosine. Thymine pairs with thymine.

• Adenine pairs with thymine. Cytosine pairs with guanine.

• Thymine pairs with guanine. Cytosine pairs with adenine.

• Cytosine pairs with cytosine. Thymine pairs with thymine.

Which molecules are needed to cut and copy segments of DNA?

• reproductive hormones

• carbohydrates

• antibodies

• biological catalysts

Which event takes place first during DNA replication?

• A single-stranded RNA molecule is formed.

• Transfer RNA links to an amino acid.

• Free nucleotides are bonded together in the correct sequence.

• The DNA molecule "unzips" along weak hydrogen bonds.

If 15% of a DNA sample is made up of thymine, T, what percentage of the sample is made up of cytosine, C?

• 15%

• 35%

• 70%

• 85%

The Molecule coded from DNA is represented by

• 1-mRNA

• 2- Codon

• 3- Amino Acid

• 4- Ribosome

Which base is normally used in the synthesis of RNA but not in the synthesis of DNA?

• adenine

• uracil

• cytosine

• guanine

DNA is able to control cellular activities most directly by regulating the process of

• meiotic division

• protein synthesis

• active transport

• selective breeding