Chapter 8
Genetics is the study of
what genes are, how they carry information, how their information is expressed, and how they are replicated and passed to subsequent generations or other organisms.
DNA in cells exists as
a double-stranded helix
double-stranded helix; the two strands are held together by
by hydrogen bonds
between specific nitrogenous base pairs: AT and CG.
A gene is a segment of DNA
DNA
DNA is a sequence of
a sequence of nucleotides that codes for a functional product, usually a protein.
The DNA in a cell is duplicated before the cell divides
before the cell divides
T or False
After division each daughter cell receives the same genetic information.
True
Genotype is
-the genetic composition of an organism,
-its entire complement of DNA
Phenotype is
-the expression of the genes:
-the proteins of the cell and the properties they confer on the organism.
The DNA in a chromosome exists as
one long double helix one long double helix associated with various proteins that regulate
genetic activity.
double helix is associated with various
associated with various proteins that regulate
genetic activity.
What shape is bacterial DNA
circular
Genomics is
the molecular characterization of genomes
Information contained in the DNA is transcribed into RNA and translated into proteins at the ribosome.
RNA and translated into proteins at the ribosome.
Information contained in the DNA is translated into
translated into proteins at the ribosome.
. During DNA replication, the two strands of the double helix separate at the
replication fork
each strand is used as a template by ___________ to synthesize two new strands of DNA
DNA polymerases
The two new strands of DNA are matched according to the rules of
nitrogenous base pairing.
The result of DNA replication is
two new strands of DNA, each having a base sequence complementary
to one of the original strands.
Because each double-stranded DNA molecule contains one original and one new strand, the replication
process is called
semiconservative.
T or F
DNA is Synthesized in one direction designated 5â-3â
T
T or F
DNA polymerase proofreads new molecules of DNA and removes mismatched bases before continuing
DNA synthesis.
T
Each daughter bacterium receives a
chromosome that is virtually identical to the parentâs
the enzyme RNA polymerase synthesizes a strand of RNA from one strand of double-stranded DNA, which serves as a template during what process
transcription
RNA is synthesized from
nucleotides containing the bases A, C, G, and U
the process in which the information in the nucleotide base sequence of mRNA is used to dictate the amino acid sequence of a protein
Translation
The mRNA associates with
ribosomes, which consist of rRNA and protein.
Three-base segments of mRNA that specify amino acids are called
codons
The genetic code refers to
the relationship among the nucleotide base sequence of DNA, the corresponding
codons of mRNA, and the amino acids for which the codons code
The start codon
AUG, codes for methionine
Translation ends when
the ribosome reaches a stop codon on the mRNA
A mutation is a change in the
nitrogenous base sequence of DNA; that change causes a change in
the product coded for by the mutated gene.
Many mutations are _________
nuetral