Chapter 12. Molecular Biology of the Gene

Which choice identifies the flow of information according to the central dogma of molecular biology?

DNA to RNA to protein

There are ___________ different types of DNA nucleotide.

four

Scientists were searching for the source of biological information about inheritance and development. When they found it, they called it the :

genetic code

The two purines bases in DNA are:

guanine, adenine

The two strands of DNA are held together by ____________ bonds.

hydrogen

The two strands of a DNA double helix are help together by ________.

hydrogen bonds

The first stage of translation, during which ribosomes assemble around mRNA is called ____________.

initiation

Codons are founds on which nucleic acid?

mRNA

The type of nucleic acid bearing codons for the amino acid sequence is called ____________.

mRNA

It is necessary for genetic material to be able to undergo changes called ______________ in order to provide genetic variety for evolution to occur.

mutations

In the term tRNA, the t stands for _____________.

transfer

The process of ______________ occurs on ribosomes, either free in the cytoplasm or bound to the endoplasmic reticulum.

translation

Which of the following would contain the most nucleotide bases, if all from the same eukaryotic gene?

Introns + exons

List the steps of translation in the correct order placing the first step at the top of the list.

1. initiation 2. elongation 3. termination

A certain portion of a protein has the amino acid sequence Lys-Gly-leu. What was the original source of this particular sequence?

It was directed by the bases on the template DNA.

A template portion of a DNA template strand has the sequence GAACCT. Assuming no modification, what would the sequence of amino acids in the proteins product (use the mRNA codon table)?

Leucine - glycine

A portion of mRNA transcript has the sequence CUGAAA. Assuming no modification occurs, what would be the sequence of amino acids in the protein product? (Use the mRNA codon table.)

Leucine - lysine

Based on you're understanding of the central dogma of molecular biology, match the following processes with the correct description. Transcription: translation: replication:

Transcription: DNA is used as a template to produce RNA translation: RNA is used to produce protein. replication: DNA is used as a template to produce duplicate molecules of DNA.

True or false: A purine base normally pairs with a pyrimidine base.

True

True or false: DNA can store information, can be replicated and can undergo rare changes.

True

True or false: The genetic code is, with few exceptions, universal.

True

True or false: a change in the DNA code will result in a change in the RNA code.

True

The term that refers to the strands of a DNA molecule being oriented in opposite directions is ____________.

antiparallel

A opening in eukaryotic DNA, containing two forks at the site of replication is called a replication ______________.

bubble

A(n) _________ is a three-nucleotide sequence in mRNA that codes for a particular amino acid.

codon

Rosalind Franklin was instrumental in the discovery that the three-dimensional shape of DNA molecule was a(n) ___________ _________.

double helix

The ___________ phase of translation allows additional amino acids to be added to the growing polypeptide.

elongation

Match the term with its definition

pre-mRNA: RNA that has not been processed yet exons: RNA that will be used for translation introns: RNA that will be removed before translation

In the 1940s, scientists had concluded that the genetic material was most likely either ________ or _________.

protein, DNA

Ribosomes are made of proteins and a type of nucleic acid abbreviated ___________.

rRNA

The major types of RNA are tRNA, mRNA and ___________.

rRNA

The process of copying a DNA molecule so that there are two copies of the same DNA is called DNA

replication

DNA replication can be describes as ___________, because the resulting daughter DNA consists of one parents strand and one daughter strand.

semiconservative

The original parent strand from which a complementary strand is made is called the _________ strand.

template

The parental strand of DNA serving as the guide for a complementary DNA daughter strand is called the ___________ strand.

template

Place these steps in DNA replication in the correct sequence beginning with the first step at the top.

1. Unwinding the DNA double helix. 2. Complementary base pairing. 3. Joining nucleotides to the growing DNA strand

Rank the following termination events in sequential order.

1. release factor binds to stop codon 2. protein product is released 3. ribosomal subunits dissociate

The two pyrimidine bases are:

thymine, cytosine

The process of synthesizing an RNA strand from a DNA template strand is called ____________.

transcription

Select the choices indication similarities between RNA and DNA.

- Both are nucleic acids - Both contain 4 types of nucleotide bases. - Both are polymers of nucleotides

Which of the following were direct contributions of the work of James Watson and Francis Crick?

- Determined that nucleotides were paired inside the double helix. - Determined that sugars and phosphates formed backbones in the DNA. - Discovered the double helix shape of deoxyribonucleic acid.

Which of the following are components of a nucleotide?

- Nitrogen-containing base - 5-carbon sugar - Phosphate

An mRNA transcript

- can be used for translation - was made frm a DNA template. - was produced by RNA polymerase

Which of the following are true of transcription but not translation?

- involves RNA ploymerase - occurs in eukaryotic nuclei

Select the characteristics of translation.

- involves a mRNA molecules - results in a protein product

Which of the following is/are true of both transcription and translation?

- occur in eukaryotes and prokaryotes - RNA is involved - several, identical products can be produced from one strand - involve nucleic acids

Ribosomes participating in production of proteins destined for secretion from the cell are located:

- on the endoplasmic reticulum

Select the choices indicating differences between RNA and DNA.

- only RNA contains the sugar "ribose". - DNA is double-stranded, but RNA is single-stranded - only RNA contains the base "Uracil"

Which of the following are characteristics of the genetic material that early scientists were seeking?

- storage of genetic information - able to undergo mutations - a stable molecule

List the sequential steps of DNA replication in prokaryotes.

1. The double helix is separated and unwound 2. DNA polymerases begins the copying process. 3. DNA polymerases meet at the termination region.

Which of the following would contain the fewest base pairs, if starting with the same size eukaryotic gene?

A post-modification mRNA transcript

What is the best explanation as to why the number of adenines in an organism's DNA is equal to its number of thymines?

Because adenine pairs with thymine in DNA

James Watson and Francis Crick contributed greatly to our knowledge of the structure of the molecule known as __________.

DNA

Match the name of the protein with its function in DNA replication.

DNA helicase: separates double-stranded DNA into single strands. Single-stranded binding protein (SSB): keeps single stranded DNA apart. DNA primase: Synthesizes short RNA strands. DNA polymerase: synthesize DNA, removes RNA and proofreads DNA. DNA Ligase: attaches DNA fragments.

Which of the following contain proper complementary DNA base pairs?

G - C A - T

A triplet code for amino acids is made up of ___________.

RNA nucleotides

Why must the genetic material be a stable molecule?

So genetic material can pass from generation to generation. So replication can be accurate.