Biology Fall Exam Review

Carbohydrates are more easily metabolized than lipids. However, on a gram-for-gram basis lipids cells with more — A. nitrogen B. proteins C. structure D. energy

• nitrogen

• proteins

• structure

• energy

Sickle-shaped red blood cells result from a mutation in the gene that codes for hemoglobin. This mutation results in sickle-cell anemia. A partial sequence of bases from a normal hemoglobin gene and a sequence that results in sickle-cell anemia are shown below. What type of mutation is depicted in this sequence?

• Insertion

• Substitution

• Deletion

• Frameshift

In certain species of plants, purple flowers (P) are dominant to white flowers (p). If two heterozygous plants are crossed, what will be the phenotype of the offspring?

• 75% purple flowers, 25% white flowers
• 75 % white flowers, 25% purple flowers

• 50% white flowers, 50% purple flowers

• 0% white flowers, 100% purple flowers

Transmembrane proteins span the width of cell membranes. Four types of transmembrane proteins are shown in a section of cell membrane.

Although these proteins have different functions, they all-

• synthesize molecules that signal other cells

• help the cell interact with its external environment

• stop chemical reactions within the cell

• remove large waste particles from the cytoplasm of the cell

A model of a DNA molecule is shown.

The arrow indicates -

• the hydrogen bond between the complementary nucleotides

• the bond between adjacent phosphate and deoxyribose molecules

• the junction of introns and exons in the sense strand of DNA

• the junction of a codon and a DNA triplet

In cattle the allele for cloven hooves (H) is dominant over the allele for mule-foot hooves (h). The phenotype for each trait is shown in the picture.

What is the probability of cloven hooves in the offspring of parents that are heterozygous for the trait?

• 25%

• 50%

• 75%

• 100%

Different types of mutations can occur in DNA. The diagram represents a type of mutation.

Which statement describes the mutation in the diagram?

• A silent mutation results in the insertion of a different amino acid.

• A substitution occurs with the adenine base.

• A deletion of a cytosine base occurs.

• A base is inserted into one strand of the DNA.

Which of these is the direct result of an error in the transcription of a DNA nucleotide?

• The nuclear membrane is ruptured.

• Amino acids do not bond to tRNA.

• A codon sequence is incorrect

• Transportation of mRNA does not occur

Four different nucleotides are used as building blocks of DNA. Which of the following can be used to distinguish one nucleotide from another?

• The shape of the deoxyribose sugar

• The nitrogenous base

• The length of the phosphate group

• The type of fatty acid

A mutation that occurs in the gametes of an organism will most likely be transferred to which of the following?

• The offspring of the organism

• The siblings of the organism

• The other organisms living nearby

• The mating partner of the organism