Biology Chapter 25

An _______ is a three-nucleotide sequence in mRNA that codes for a particular amino acid.

codon

Which of these are removed from a mRNA during processing in the nucleus?

copies of introns

The two strands of a DNA double helix are held together by

hydrogen bonds

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

initiation

The noncoding portions of a gene that are removed from the mRNA copy during processing are called .

introns

Select the characteristics of translation.

involves a mRNA molecule results in a protein product

Which of the following are components or structures of a ribosome?

large subunit protein small subunit ribosomal RNA

Which structure carries genetic information from the DNA to the ribosome?

mRNA

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

nucleic acids, or proteins

DNA is composed of units called ___________ , each of which contains a phosphate group, a 5-carbon sugar, and one of 4 nitrogen-containing bases.

nucleotides

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

occurs in eukaryotic nuclei involves RNA polymerase

At one end of a mature mRNA there is a cap, at the other is a(n) ______.

poly-A tail

The enzyme that assists with complementary base pairing and adding new nucleotides to the growing strand during DNA replication is DNA .

polymerase

Select the products for which a gene may encode instructions for building.

protein RNA

According to Mark Gerstein a gene should be defined as a genomic sequence (either DNA or RNA) directly encoding functional products, either

protein or RNA

The DNA bases cytosine and thymine are smaller, single-ringed bases called

pyrimidine

Which RNA molecule is associated most closely with both ribosomes and translation?

rRNA

The production of two DNA copies from a single original DNA molecule is called DNA

replication

Protein synthesis (translation) occurs at which of the following locations within eukaryotic cells? (Select all that apply)

rough endoplasmic reticulum cytoplasm

DNA replication can be described as __________________ , because the resulting daughter DNA contains one parent strand and one daughter strand.

semi-conservative

Select the items that play a part in initiation of translation.

small ribosomal subunit messenger RNA initiator tRNA large ribosomal subunit

The codon near which the small ribosomal subunit attaches to the mRNA molecule to be translated, which codes for methionine (AUG) is called the ________ codon.

start

During translation initiation, the small ribosomal subunit and initiator tRNA attach in the vicinity of the _____.

start codon

Select the items that play a part in translational initiation.

start codon mRNA initiator tRNA

The sides of the ladder model of DNA are __________ __________ backbones

sugar phosphate

Anticodons are found on which nucleic acid?

tRNA

The specific type of nucleic acid bearing anticodons for the amino acid sequence is abbreviated .

tRNA

Which nucleic acid is the physical carrier of individual amino acids?

tRNA

During termination,

the polypeptide is released from the ribosome.

During initiation,

the ribosomal subunits assemble.

The process by which an RNA strand is synthesized from a DNA template strand is called .

transcription

If each codon were composed of only 1 nucleotide, for how many amino acids (out of the 20) would there NOT be a code for?

16

If codons were composed of only 2 nucleotides each, how many amino acids (out of the 20) would there NOT be a code for?

4

Which of the following are components of a nucleotide?

5-carbon sugar Nitrogen-containing base Phosphate

Which of the following contain proper complementary DNA base pairs?

A - T G - C

Select the findings of Erwin Chargaff regarding DNA composition.

A = T pyrimidines = purines G=C

If a certain section of a template strand of DNA had the sequence TATGCCCG, what would the mRNA transcript's sequence be?

AUACGGGC

Which of the following DNA bases are purines?

Adenine and Guanine

During the 1940s, scientists considered which two molecules most likely to be genetic material?

DNA and Protein

The enzyme responsible for maintaining the complimentary natures of the DNA strands during DNA replication is

DNA polymerase.

The purpose of mRNA is to carry information from _______ to the _______

DNA, Ribosome

Erwin Chargaff determined that the number of _________ like guanine and adenine always equal the number of __________ like cytosine and thymine.

Purines, pyrimidine

The enzyme that is responsible for catalyzing the process of transcription is called

RNA Polymerse

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

RNA is involved involve proteins and nucleic acids stage in gene expression occur in eukaryotes and prokaryotes

According to Mark Gerstein a gene should be defined as a genomic sequence (either DNA or RNA) directly encoding functional products, ________ or _________

RNA or Protein

Select the items that describe events occurring during the termination phase of translation.

Release factor binds to stop codon. Ribosomal subunits dissociate. Protein product is released.

Which scientist's X-ray diffraction data helped to demonstrate the double helix structure of DNA?

Rosalind Franklin

Why did early molecular geneticists know that the genetic material needed to be a stable molecule? (Choose all that apply.)

So it could be passed from one generation to the next. So it could be replicated accurately

Which two nucleotide components bind together when DNA forms a strand?

Sugar and Phosphate

Which of the following DNA bases are pyrimidines?

Thymine and Cytosine

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

True

True or false: All three major types of RNA are produced by transcription of DNA.

True

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

True

If a certain section of a template strand of DNA had the sequence AATGCCCG, the mRNA transcript's sequence would be

UUACGGGC

What structure is formed when two molecular strands wind around each other in a double spiral?

a double helix

The synthesis of new DNA double helix molecules from a pre-existing parent molecule is called _______.

DNA Replication

Select the characteristics that researchers suspected the genetic material would have prior to the discovery that the genetic material was DNA.

ability to store information passes from one generation to the next accurate replication

Select the items that play a part in elongation during translation.

amino acids transfer RNA messenger RNA elongation factors

During elongation,

amino acids are brought to the ribosome sequentially.

During the process of translation, the codon matches up with its complement, the

anti-codon

DNA replication is called semiconservative because

each new DNA is one-half formed from the original molecule.

The phase of translation that allows additional amino acids to be added to the growing polypeptide is called

elognation

Which contains instructions for the production of a polypeptide?

exon

During mRNA processing, copies of ______ from the DNA are joined together.

exons

The coding portions of a gene that are joined during mRNA processing are called

exons

Transcription and translation are two stages in the process of gene

expression

Which of the following are possible locations where ribosomes serve as sites for protein synthesis in a eukaryotic cell?

free in cytoplasm bound to endoplasmic reticulum

Rosalind Franklin's X-ray diffraction photograph demonstrated that DNA

was a double helix.