3.2 Practice- DNA

Which choice describes DNA after replication has taken place?

• one molecule with two original strands and one molecule with two new strands

•  two molecules, each with one original and one new strand

•  two molecules, each with two new strands

•  two molecules, each with two old strands

Which of the following would most likely cause a mutation?

• the placement of ribosomes on the endoplasmic reticulum

•  the insertion of a nucleotide into DNA

•  the movement of transfer RNA out of the nucleus

• the release of messenger RNA from DNA

A diagram of a cellular process is shown below. Which of the following identifies the process shown at point Z?

• Translation

• Translocation

• Replication

• Transcription

During transcription the DNA base sequence is transcribed into a complementary mRNA sequence. A codon table like the one shown below lists the amino acids coded for by codons of mRNA bases. A segment of DNA has undergone a mutation in which one nucleotide has been changed (ACG is now ACA). Use the codon table to determine whether or not this mutation will cause a change in the phenotype (physical characteristics) of the organism. 

• yes, the phenotype of the organism would change because a new amino acid will be coded for .

• yes, the phenotype of the organism would change because any change in the DNA genotype will cause a change in phenotype.

• Even though the DNA genotype changed, the sequence still codes for the same amino acid, so no change in phenotype will occur.

• It is impossible to determine if a change in phenotype will occur using only the DNA sequence.

The sequence of DNA below is part of a gene. How many amino acids will be coded for by this segment? 5' ATC-AGC-GCT-GGC 3' 

• 4

• 8

• 12

• 20

Mutations within a DNA sequence are:

• natural processes that produce genetic diversity

•  natural processes that always affect the phenotype

• unnatural processes that always affect the phenotype

• unnatural processes that are harmful to genetic diversity

Use the picture to identify the TRUE statement:

• Antibodies are created by the immune system body cells to fight specific infections

• Any antibody can match up with any antigen

• Antibodies are foreign pathogens that must be removed by the immune system.

• Antibodies are the first step of the nonspecific immune system

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. After the vaccine is administered, what type of immune response is triggered in the body?

• Secretion of antigens providing a non-specific immune response.

• Absorption of histamines throughout the body.

• Production of temporary resistance to the disease.

• Production of antibodies providing specific immunity.

Some diabetic people cannot make their own insulin (a protein necessary for metabolism).  Instead they have to inject insulin into their bodies.  This human insulin is manufactured by yeast cells in large factories.  What aspect of DNA allows for yeast cells to be able to manufacture a human protein?

• DNA Replication involves a series of steps that are identical in yeast and human cells.

• Yeast DNA sequences are identical to human DNA and therefore they can be used interchangebly.

• DNA components are universal and thus are found in both yeast and humans

• Both yeast and humans have the same number of chromosomes

The process of DNA replication is to be semi-conservative. What is meant that DNA replication follows a “semi-conservative” model?

• After DNA replication, each molecule contains one old strand and one new complementary strand.

• After DNA replication, each molecule has new DNA strands

• None of these identify the “semi-conservative” model.

• After DNA replication, each molecule is made into mRNA