Biology- ch. 7

Select all of the following that describe RNA.

-the nitrogenous base uracil is used instead of thymine -can be single-stranded -can catalyze chemical reactions -nucleotides contain the sugar ribose

Match each term with its correct description.

Chromosome- discrete package of DNA coiled around proteins DNA molecule- includes many genes Gene- a sequence of nucleotides that codes for a specific protein or RNA molecule Genome- all of the genetic material in a cell

In an RNA molecule, a(n) ______ is a genetic "code word" that corresponds to one amino acid.

Codon

The instructions in ______ encode the information that a cell needs to produce proteins, which are vital to living things.

DNA

Within the DNA double helix, the so-called backbone is composed of ______ sugars alternating with phosphate groups.

Deoxyribose

Match the following scientists with their contribution to the discovery of the structure of DNA.

Erwin Chargaff: Determined that DNA contains equal amounts of adenine and thymine and of guanine and cytosine. Maurice Wilkins and Rosalind Franklin: Used X-ray diffraction to determine the three-dimensional shape of the DNA molecule. James Watson and Francis Crick: Used the known ratios of nucleotides along with the X-ray diffraction data to build a ball-and-stick model of the DNA double helix.

True or false: Complementary base pairing rules state that in DNA, A pairs with G and T pairs with C.

FALSE

In 1953, James Watson and ______ built a ball-and-stick model of the DNA double helix using two lines of evidence to deduce the structure.

Francis Crick

Select all of the following that are true with respect to genomes.

In prokaryotic cells, the genome usually consists of just one circular DNA molecule. In eukaryotic cells, the genome is usually divided up into multiple chromosomes.

What is produced during translation?

Protein

In the "central dogma," information flows from DNA to RNA to ______.

Proteins

In a process called ______, an RNA copy of a gene sequence on the DNA molecule is made.

Transcription

In a process called ______, an RNA molecule is used to produce a protein.

Translation

Two strands of DNA within the double helix are said to be complementary to each other because ________ on one strand always pairs with thymine on the opposite strand, and cytosine on one strand always pairs with _________ on the opposite strand.

adenine; guanine

During transcription, a gene's DNA sequence is transcribed into a

complementary RNA molecule.

A DNA molecule consists of two intertwining strands of nucleotides that form a _________

double helix.

A(n) ______ is a sequence of DNA nucleotides that codes for a specific protein or RNA molecule.

gene

All of the genetic material that is within a cell is called its ______

genome

Select all of the bases that can be present in DNA nucleotides.

guanine adenine thymine cytosine

The DNA double helix resembles a twisted ladder, where the rails of the "ladder" (also called the "backbones") are composed of alternating deoxyribose sugars and phosphate groups joined by covalent bonds, while the rungs of the ladder are composed of A-T and G-C base pairs joined by ______________ bonds.

hydrogen

The DNA double helix is made up of two strands of ______ monomers oriented in opposite directions.

nucleotide

Subunits called ______ are the building blocks of DNA.

nucleotides

Messenger RNA carries information that specifies the amino acid sequence of a __________

protein

What role does DNA play in the cell?

store instructions for making proteins

In the "central dogma" describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called ________, and the information in RNA is used to direct the synthesis of a protein in a process called ________.

transcription; translation