DNA Review for STAAR

the hydrogen bond between complementary nucleotides

A model of a DNA molecule is shown below. The arrow indicates — F the bond between adjacent phosphate and deoxyribose molecules G the junction of introns and exons in the sense strand of DNA H the hydrogen bond between complementary nucleotides J the junction of a codon and a DNA triplet

The offspring of the organism

A mutation that occurs in the gametes of an organism will most likely be transferred to which of the following? A The siblings of the organism B The offspring of the organism C The other organisms living nearby D The mating partner of the organism

Messenger RNA

A section of a nucleic acid is shown in the photo. The process represented in the diagram produces a molecule that is complementary to the template strand of DNA. What type of molecule is produced? A New DNA B Polypeptide C Messenger RNA D Carbohydrate

As a sequence of nucleotides

A segment of DNA is represented in the illustration.How is information for a specific protein carried on the DNA molecule? F As a sequence of nucleotides G In the double-helix shape of the condensed chromosome H In the ratio of adenines to thymines J As a pattern of phosphates and sugars

Methionine, serine, histidine, aspartate, glycine

A segment of DNA produces methionine, threonine, histidine, aspartate, and glycine when translated. A substitution mutation occurs and causes the synthesis of the segment as shown. New DNA strand: 3'-TACAGGGTGCTACCCACT-5' Which is the new peptide chain when the new DNA segment is translated? A Methionine, leucine, histidine, aspartate, glycine B Methionine, phenylalanine, histidine, aspartate, glycine C Methionine, proline, histidine, aspartate, glycine D Methionine, serine, histidine, aspartate, glycine

Gene expression that is regulated by temperature

At birth Himalayan rabbits are usually white over their entire bodies. But when parts of their bodies reach temperatures below 35°C, a pigment that causes these parts to turn black is produced. Which of the following is most likely the cause of this phenomenon? A Poor blood circulation B Infection caused by cold temperatures C Gene expression that is regulated by temperature D A trait that is both sex-linked and hormone-dependent

Nitrogenous bases

Characteristics such as a widow's peak or attached earlobes are determined by the genetic code. Which components of DNA are referred to as the genetic code? F Phosphate groups G Nitrogenous bases H Deoxyribose sugars J Hydrogen bonds

F 0% (You must make a Punnett square and identify the genotypes of each of the parents. In this case both genotypes would be [ff].

Chickens can have different types of feathers. Frizzled feathers curl toward a chicken's head. Assume that feather type is determined by a single gene and that the allele for frizzled feathers is dominant over the allele for straight feathers. In a cross between two chickens with straight feathers, what percentage of the offspring can be expected to have frizzled feathers? F 0% G 25% H 50% J 100%

H. 5' ACATCGACGCGCA 3'

Each strand of a DNA molecule contains nitrogenous bases that pair with other nitrogenous bases in very specific ways. A diagram of a section of DNA is shown in the picture. Which DNA strand is complementary to the one in the picture? F. 5' AUGGCUGCGCGUA 3' G. 5' TGTAGCTGCGCGT 3' H. 5' ACATCGACGCGCA 3' J. 5' TCGCGCAGCTACA 3'

FAD is the result of a genetic change in one or more chromosomes.

Early-onset Alzheimer's disease affects people under the age of 65. Less than five percent of people who are diagnosed with Alzheimer's disease have this type. Many cases of early-onset Alzheimer's disease are inherited, a type known as familial Alzheimer's disease (FAD). Which statement is best supported by this information? F FAD is the result of a genetic change in one or more chromosomes. G Natural selection will continue to reduce the incidence of FAD. H FAD affects only the genes of middle-aged people. J Deletion of one amino acid causes FAD.

The nitrogenous base

Four different nucleotides are used as building blocks of DNA. Which of the following can be used to distinguish one nucleotide from another? F The nitrogenous base G The shape of the deoxyribose sugar H The length of the phosphate group J The type of fatty acid

DNA contains codes for proteins, which are necessary for the growth and functioning of an organism.

How does DNA in cells determine an organism's complex traits? A DNA contains codes for proteins, which are necessary for the growth and functioning of an organism. B DNA separates into long single strands that make up each part of an organism. C DNA produces the energy an organism needs in order to grow. D DNA folds into the nucleus of each of the cells of an organism.

The genes regulating wing color in butterflies are influenced by environmental factors.

In 1917 the biologist Thomas Hunt Morgan conducted studies in which he kept some caterpillars in the dark and placed some others under red, green, or blue lights. Exposure to red light produced butterflies with brightly colored wings. Exposure to green light resulted in dark-colored wings. Exposure to blue light or no light resulted in pale-colored wings. What was the most likely conclusion of Morgan's research? F The pigment in butterfly wings absorbs light from the environment. G The phenotypic expression of wing shape depends on color pigmentation in butterflies. H The genes regulating wing color in butterflies are influenced by environmental factors. J Caterpillars exposed to red and green light are healthier than caterpillars exposed to no light or blue light.

double-helix structure of DNA

In 1952 Rosalind Franklin took the x-ray photograph shown below, which gave the world its first look at DNA. By studying this photograph, scientists gained knowledge about the — F role of DNA in protein synthesis G mutation of nucleotide sequences in DNA H sequence of DNA that makes up the human genome J double-helix structure of DNA

Nitrogenous bases are added.

In the 1960s the molecular biologist George Streisinger developed the strand-slippage hypothesis. Streisinger noticed that mutations occurred in areas of DNA that contained many repeated sequences. When a strand-slippage error occurs, an insertion mutation can result. How does the insertion mutation affect the DNA? A Nitrogenous bases are added. B Nitrogenous bases are exchanged. C Nitrogenous bases are damaged. D Nitrogenous bases are deleted.

mRNA

In the early 1900s a scientist hypothesized a link between DNA and the production of proteins in the cytoplasm. However, the fact that DNA could not be found outside the nucleus led scientists to believe that another substance was also involved in the synthesis of protein in the cytoplasm. In the 1940s scientists performed an experiment that ultimately identified the site of protein synthesis. They also identified the molecule responsible for transporting information from the nucleus to the site of protein synthesis. What was this newly identified molecule? F A gene G mRNA H ATP J Thymine

Galactose

Lactose is found in milk products. It is converted by the body into a usable form in a series of chemical reactions. The diagram shows the series of reactions that convert lactose into a usable form If Enzyme 2 is denatured, the levels of which substance will increase? F Lactose G Galactose H Galactose-1-phosphate J Glucose-6-phosphate

The order of nitrogenous bases determines the order of amino acids in the proteins synthesized.

Nitrogenous bases are located on both strands of the DNA double helix. What is the significance of the nitrogenous bases? A The number of adenines and cytosines determines the type of RNA that will be produced. B The order of nitrogenous bases determines the order of amino acids in the proteins synthesized. C The amount of thymine and guanine in the DNA molecules determines the length of the genes. D The type of hydrogen bonding between the nitrogenous bases determines which amino acid will be added to the peptide chain.

Cell division is unregulated.

Oncogenes are mutated forms of genes. Oncogenes can transform a cell into a tumor cell. Some tumor cells are benign, while others are malignant. How does the presence of an oncogene lead to the formation of a tumor? F ATP production is inhibited. G Cell division is unregulated. H Somatic cell growth is inhibited. J Antibody activity is unregulated.

DNA bases

Organisms can be classified based on homology, which is shared characteristics inherited from a common ancestor. In the past, homologies were based on studies of anatomical structures and patterns of embryonic development. In more recent years, the use of molecular biology techniques has allowed homologies to be compared at the level of nucleotide sequences. Nucleotide sequence comparisons are possible because all organisms share which of the following? F DNA bases G Cellular organelles H Division of the nuclear chromosomes J Types of proteins needed for cellular functions

Transcribing information in the DNA sequence for use by the cell

Part of an important cellular process involving a DNA strand is modeled below. What is the purpose of this cellular process? F Preserving genetic information for future generations G Deleting the information in the sequence produced from the DNA template H Transcribing information in the DNA sequence for use by the cell J Producing more nucleotides for the DNA sequence

Substitution

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? A Substitution B Insertion C Deletion D Frameshift

perform different functions

The complex carbohydrates pictured below are made by linking molecules of glucose.In all three complex carbohydrates, the subunits of glucose are bonded together differently. Because they have different structures, they most likely — A contain different chemical elements B form different proteins C carry different nucleotides D perform different functions

Process: transcription; product: mRNA

The initial steps in gene expression are modeled below. Double-stranded DNA first unwinds into two strands.Which process and product are represented in Diagram 2? A Process: transcription; product: mRNA B Process: translation; product: protein C Process: replication; product: tRNA D Process: recombination; product: polymerase

When only a small amount of DNA is available, such as at a crime scene

The photograph shows a laboratory investigator examining samples of DNA in a procedure called PCR, or polymerase chain reaction. Using PCR, the investigator can create thousands or even millions of copies of a fragment of DNA for closer investigation. In which of these situations would PCR be most useful? F When only a small amount of DNA is available, such as at a crime scene G When the DNA of identical twins is being mapped H When the genome of a population is being analyzed for preventable diseases J When the blood type of a DNA donor is known

Providing the instructions for the traits of an organism

The sequence of nitrogenous bases in DNA varies widely. The sequence of the bases in DNA is most important for which of the following? A Providing the instructions for the traits of an organism B Preventing mutations from occurring during DNA replication C Allowing the DNA to have the shape necessary for replication D Helping form the sugar-phosphate backbone of DNA molecules

Met, Val, Lys, Arg, Gln, Ser

Which of the following polypeptides is coded for by the mRNA sequence 5'AUGGUUAAACGACAAUCC3'? F Val, Lys, Phe, Gly, Ser G Met, Asp, Phe, Ala, Arg H Met, Val, Lys, Arg, Gln, Ser J Ile, Gln, Lys, Asp, Gly, Leu, Ser