Unit 4 Molecular Genetics

What makes up the DNA?

• tRNA

• nucleotide

• amino acids

• mRNA

what do the lines between the A-T and G-C pairs represent?

• ionic bonds

• hydrogen bonds

• covalent bonds

• van der walls forces

If the DNA molecule with 6 paired nitrogen bases were transcribed, how many codons would the resulting mRNA molecule contain?

• 1

• 2

• 3

• 6

If there are 6 pairs of nitrogen bases, how many nucleotides would be created?

• 2

• 1

• 6

• 12

Which portion of the DNA molecule varies from nucleotide to nucleotide and thus serves as the portion of the nucleotide which codes for amino acid sequences?

• phosphate sugar

• ribose sugar

• nitrogenous bases

• hydrogen bonds

Tags

NGSS.HS-LS1-1

Sickle Cell Anemia

Sequence for Normal Hemoglobin

DNA Sequence

ATGGTG CAC CTG ACT CCT GAG GAG AAG TCT GCC GTT ACT

Amino Acid Seq.

STARTValHisLeuThrProGluGluLysSerAlaVal

The Sequence for Sickle Cell Hemoglobin

DNA Sequence

ATGGTG CAC CTG ACT CCT GTG GAG AAG TCT GCC GTT ACT

Amino Acid Seq.

STARTValHisLeuThrProValGluLysSerAlaVal

Sickle Cell Anemia is a blood disorder caused by an error in the amino acid sequence of the protein hemoglobin. Figure 2 depicts the normal hemoglobin DNA sequence and amino acid sequence and the sequences found in patients affected by sickle cell anemia. Why would the highlighted changes likely cause problems for affected individuals?

• Different amino acids have different polarities. The change in the amino acid sequence thus causes a change in the overall shape of the protein. Since structure largely determines function, the changed protein doesn’t function correctly.

• The indicated changes should have little effect on the overall protein structure/function. The problem must have something to do with the mRNA instead of the DNA.

• Since “Val” and “Glu” are very similar amino acids, the amino acid substitution is not the cause of the symptoms associated with sickle cell. The problem must be related to the environment.

• none of the above

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Sickle Cell Anemia

Sequence for Normal Hemoglobin

DNA Sequence

ATGGTG CAC CTG ACT CCT GAG GAG AAG TCT GCC GTT ACT

Amino Acid Seq.

STARTValHisLeuThrProGluGluLysSerAlaVal

The Sequence for Sickle Cell Hemoglobin

DNA Sequence

ATGGTG CAC CTG ACT CCT GTG GAG AAG TCT GCC GTT ACT

Amino Acid Seq.

STARTValHisLeuThrProValGluLysSerAlaVal

What mRNA would be transcribed from the normal hemoglobin DNA?

• TAC CAC GTG GAC TGA GGA CAC CTC TTC AGA CGG CAA TGA

• UAC CAC GUC GAC UGA GGA CUC CUC UUC AGA CGG CAA UGA

• UAC CAC GUG GAC UGA GGA CAC CUC UUC AGA CGG CAA UGA

• TAC CAC GTC GAC TGA GGA CTC CUC TTC AGA CGG CAA TGA

Tags

NGSS.HS-LS1-1

Sickle Cell Anemia is caused by a “point” mutation. Which of the following correctly describes this type of mutation?

• A nucleotide or group of nucleotides is inserted into the wrong location in the DNA. This changes the order in which the nucleotides are “read” and results in the synthesis of an incorrect amino acid sequence.

• A nucleotide or group of nucleotides is deleted from the DNA. This changes the order in which the nucleotides are “read” and results in the synthesis of an incorrect amino acid sequence.

• An incorrect nucleotide is substituted for the correct nucleotide. This changes one codon in the gene sequence. This results in a change in one amino acid in the protein. This change in one amino acid changes the overall shape/function of the protein.

• Several incorrect nucleotides are substituted for their correct counterparts. This changes several of the amino acids in the protein and results in a protein that is misshapen and not functional.

Tags

NGSS.HS-LS3-2

What process is occurring in Figure 3?

• DNA replication

• transcription

• translation

• mitosis

What is structure 1?

• tRNA

• mRNA

• DNA

• rRNA

Tags

NGSS.HS-LS1-1