Biology Unit 5 Test

How many sugar-phosphate strands exist in each RNA molecule?

1

Which is an example of a genetic mutation?

An extra nucleotide is added during DNA replication.

sequence of DNA reads GTC AAT. What would the complementary DNA sequence read?

CAG TTA

A portion of a gene on one strand of DNA has the following nitrogen base sequence: GCT-ACC-GAA-TAC Which nitrogen base sequence will most likely be transcribed on the messenger RNA molecule?

CGA-UGG-CUU-AUG

Which statement best describes the relationship that exists among proteins, DNA, and cells?

Cells contain DNA, which controls the production of proteins.

Proto-oncogenes code for proteins that stimulate cellular growth and division. What happens when these genes fail to regulate the amount of protein produced?

Cells continue to grow and divide in an uncontrolled manner.

What is the relationship between genetic mutations and DNA?

Changes in DNA lead to genetic mutations.

Every copy of a particular protein manufactured by a cell shows the same incorrect amino acid at the same point in its structure. According to the central dogma of molecular biology, in which structure does this error originate?

DNA

What is the role of DNA in translation?

DNA serves as the original template for protein synthesis.

How do DNA and proteins work together to affect the metabolism of energy in cells?

DNA supplies the instructions for amino acids to form specific proteins like enzymes, which speed up the metabolism in cells.

Some of the existing genes of an organism mutated randomly. Below shows the DNA sequence before and after. Before: A T C G U T A T A G G A C T C After: A T C G U T A G G A C T C What will most likely be the result of the above mutation?

Different proteins than before will be produced.

What does the replication of DNA during interphase ensure during cell replication?

Each daughter cell gets an exact copy of the cell's DNA.

Four types of cells from a parent organism are shown in the table. All four cells are exposed to radiation that changes the DNA in the parent cells. Which of the parent cells can transmit the changed DNA to the offspring?

Egg Cell

What evidence best supports the conclusion that all cells have the same DNA?

Fertilization produces one cell, and that cell divides by mitosis.

During DNA replication, the parent DNA strand CGA AGT GGC is matched with which complementary DNA strand?

GCT TCA CCG

Dr. Tanaka discovered a new virus. The virus has a single strand of a nucleic acid, but she does not know if it is DNA or RNA. After running tests, she concludes that it is DNA. Which of the following would lead her to that conclusion?

It contains thymine.

What is the significance of the sequence of nucleotides?

It determines the type of protein being produced.

Which will most likely cause variations to occur within a species?

Mutation

Two segments of DNA have the exact same number of each nucleotide. Do they necessarily code for the same protein?

No, hereditary information is passed through the order of the nucleotides in a gene.

Several enzymes work together to repair defects in DNA caused by replication errors or environmental damage. One enzyme cuts out the damaged nucleotide section and other enzymes replace the damaged section with the correct sequence. What would most likely happen if a genetic defect prevented the cell from producing one or more of these enzymes?

Potentially hazardous mutations would accumulate in the cell.

Why is it important for DNA to be duplicated exactly before a cell divides?

So genetic information is correctly passed on to govern the cellular processes in the new daughter cells.

Organism 1 inherits a mutation from its parents. Organism 2 is exposed to a substance in its environment that causes a mutation. Which of these best describes how the mutations are different?

The mutation in Organism 1 first appeared in a gamete.

What would happen to an organism if DNA did not replicate itself?

The organism would not be able to grow or reproduce.

Amanda gets protein at lunch by eating a chicken sandwich. How can Amanda's body use the protein in the chicken to build protein in her cells?

The proteins in the chicken are broken down into amino acids, and the DNA in Amanda's cells uses those amino acids to build human proteins.

Which explains how the second strand of DNA compares with the first strand of DNA?

The second strand is a complement of the first strand.

The illustration below shows DNA replication before cell division. Which best describes the role of the free floating nucleotides (A, C, G, and T) in the illustration?

They are the building blocks that are used to make the new strands.

How are all living organisms similar?

They contain the same four nitrogen bases which code for specific proteins.

Which is true for all organisms?

Translation is when RNA makes proteins.

A segment of mRNA contains the following codons AUG CAA GGU GAG. Which are the complementary tRNA anticodons?

UAC GUU CCA CUC

This diagram shows the codons for mRNA. 22182 What is a possible DNA sequence for the amino acid sequence phenylalanine-glycine-threonine?

UUU GGG ACC

The table shows a few messenger RNA codons. Which point mutation would result in the formation of a new protein?

UUU to UUA

Which best describes a mutation induced by radiation?

a change in DNA sequence

DNA stores the genetic instructions transferred from one generation to the next. What is DNA?

a molecule

Consider the DNA sequence below: TAC GCA CTG The sequence was exposed to radiation and formed this mutated sequence: TAC GCA GTA CTG What type of mutation is this an example of?

addition

A segment of DNA has the base sequence: TGA GAC TGC AGC A mutation occurs during replication and produces the sequence: TGAGACATGCAGC Which mutation has most likely occurred?

an insertion

The directions for making a protein

are carried by DNA.

This is an mRNA codon chart. An organism has the DNA sequence TAC TGC CCA ATA. 22182 Why is it possible for a different organism with the DNA sequence TAC TGT CCG ATG to produce the same protein?

because more than one codon codes for the same amino acid sequence

What is the role of messenger RNA (mRNA) in protein synthesis?

carry the DNA instructions for making proteins from the nucleus

Which is the most accurate model to show how amino acids form proteins?

cars on a train

Which statement best describes the semiconservative replication sequence of the DNA sequence CCGCAT?

complementary bases in the same order

During replication in the nucleus, what is responsible for pairing with DNA nucleotides on the open strand?

free-floating nucleotides

Which is the key to a cell's ability to differentiate?

genes

Which type of bond, denoted by the arrows, allows DNA to be readily replicated?

hydrogen bond

This chart shows which amino acids are produced from different combinations of mRNA. Codons in mRNA 28125 What amino acids would be produced from the transcribed DNA sequence? TAT GCA TGC

isoleucine-arginine-threonine

What must match in order for amino acids to be linked into a protein by the ribosome?

mRNA codon and tRNA anti-codon

Which correctly places the events of protein synthesis in order?

make mRNA; mRNA moves to ribosomes; mRNA pairs with tRNA; peptide bonds form between amino acids

Which most closely matches the goal of protein synthesis?

making a protein

During transcription, the genetic information for making a protein is rewritten. Which molecule is formed during transcription?

messenger RNA

What are the subunits of DNA and their function?

nucleotides that store information

The table below shows a sequence of activities during a cell process. Order Activity 1st Nitrogenous base sequences carry codes. 2nd Amino acids are linked into long chains. 3rd Bonding and folding result in different forms. 4th Different forms allow different functions. Which type of macromolecule is the product of this process?

protein

A new organism is found in the rain forest. It is part of the plant kingdom. What process would it most likely rely on to generate tissue and grow?

protein synthesis

Which of the following is responsible for determining the traits of an organism? Standard(s)

sequence of nucleotides

Instead of a DNA code reading ACG TTA CCG, a mutation causes it to be coded as ACG ATA CCG. Which type of mutation is responsible for this change?

substitution

Which type of mutation is shown in the following DNA sequence?

substitution

Which factor most affects the order of amino acids in a protein?

the DNA located in the nucleus of the cell

Which nucleotide is complementary to adenine?

thymine

Which process produces mRNA?

transcription of DNA

Which nitrogenous base is found only in RNA?

uracil

A mutation has occurred within a cell, and it produces the wrong protein. If the mistake originated during the very beginning stages of protein synthesis, when did the mistake occur?

when the mRNA message was made from the DNA template

When does a polypeptide chain stop forming?

when the ribosome reaches a stop codon