Unit Review Flashcards
Describe the process of replication
It is a DNA reproduction. New cells are being made.
DNA has 4 N-bases. What are these bases, and which pair up with each other?
Adenine and Thymine
Guanine and Cytosine
What is a nucleotide?
A structure consisting of a sugar, nitrogen base, and phosphate
What is the bond called that holds complementary bases together?
Hydrogen bonds
What bases are Pyrimidines? Purines?
Pyrimidines - C,U,T
Purines - A, G
Process of replication?
New strands of DNA are made from old strands and new nucleotides
Semi conservative replication?
Parental dna strands separate and are templates, produce dna molecules that have one strand of parental dna and one strand of new dna
What is a mutation?
DNA is not copied correctly, resulting in a permanent change that can either be harmful, beneficial or neutral
Two causes of mutation?
1: chemicals
2: high energy forms of radiation
What are two examples of a MUTAGEN?
X-rays, ultraviolet radiation
What is frameshift mutation?
A SINGLE n-base is lost or added to a DNA strand; results in mRNA out of position by one base
What is point mutation?
A SINGLE BASE in a gene has been changed or substituted; changes one mRNA codon and one amino acid in the protein
Ex. AAG becomes AAU
Frameshift mutation and point mutation are similar in that something happens to a ______ ______.
SINGLE BASE.
What is an aneuploidy disorder?
Having an abnormal number of chromosomes.
What is Down’s Syndrome?
Trisomy 21
Extra chromosome on #21
What is Klinefelter’s?
XXY
Person considered male
Extra X chromosome
What is Turner’s syndrome?
XØ
Person considered FEMALE
Missing or incomplete X chromosome
What is non-disjunction?
The addition or loss of a whole chromosome
Which chromosomes do Klinefelter’s and Turner’s syndrome occur on?
The 23rd pair, sex chromosomes
Differences between RNA and DNA?
DNA: double stranded, has thymine, is in the nucleus
RNA: single stranded, has uracil, in the cytoplasm
Arrange these terms from smallest to largest:
CELL NUCLEUS CHROMOSOME
NUCLEOTIDE DNA
Nucleotide, DNA, chromosome, nucleus, cell
What is a triplet?
3 n-bases together coding for an amino acid.
What is transcription?
It’s when DNA is transcribed into mRNA, happens in the nucleus.
What is translation?
The translation of mRNA onto the polypeptide chain. Happens in the ribosome.
What is the function of DNA, mRNA, tRNA, and rRNA?
DNA: contains genetic info needed to carry out cell activities
mRNA: contains the translated DNA info
tRNA: delivers the right anticodon and the amino acid, to the ribosome
rRNA: helps make the ribosome and read the mRNA
What causes Downs syndrome, turners and klinefelters?
Nondisjunction
