NEW 2 Flashcards
DNA ligase
JOINS small fragments into continuous chain
Transcription is
DNA –> RNA in nucleus
Non-disjunction
change in chromosome # during MEIOSIS
DNA Polymerase
Unattached nucleotides polymerized into new strand
Translocation
- changes chromosome structure
- two NON-homologs exchange parts
X Chromosome Inactivation
-happens during embryo
development in FEMALE mammals
-male/female have one “ACTIVE X” in cells
Complementary Base Pairing Rules***
- A with T
- G with C
DNA replication occurs in 5 to…
3 directions (new strand)
DNA polymerases and DNA ligase also repair DNA…
damaged by radiation / toxic chemicals
Either mother’s or father’s X may…
become inactive
DNA replication proceeds in two directions at
many origins of replication at once
Protein Therapy
gives patients protein they lack
ex. clotting factor for hemophiliacs
Once X becomes inactivated in cell, ALL parts of cell
have SAME inactive X
Early identification of genetic disorders are important for…
prevention & treatment
Physiological Therapy
baby w/ PKU removes phenylalanine from diet
Fetal cells in AMNIOTIC fluid studied for chromosome/gene defects
Amniocentesis
Chorionic Villus Sampling
removal & analysis of fetal cells in CHORIN
Gene Mapping - helps screening &…
treatment of genetic disorders
Gene Therapy
-replace bad genes w/ normal genes
Replication does NOT continue on..
5 to 3 template, forms SHORT segments
Prenatal Diagnosis
determines genetic makeup of fetus
Humans have
> 6 billion base pairs
Female mammals are _______ in X chromosome inactivation
mosaics
ex. calico cat
Gene disorder carriers can be found through pedigrees, …
biochemical analyses or genetic tests
DNA Model is made of…
TWO nucleotide chains: double helix
Occurs when homologous pair DOSENT separate during meiosis 1
non-disjunction
DNA Replication takes place in…
-S phase of interphase
Sugar-phosphate are
-sides of DNA ladder
________ _____ hold DNA strands together
Hydrogen bonds
DNA has EQUAL amounts of
- “A+T”
- “G+C”
Semiconservative replication
each NEW molecule consist of one old strand, one new
Crucial to replication
base pairing
DNA replication CONTINUES on _ to _ template
3 to 5
Genetic info flows from DNA —>
RNA —> protein
DNA synthesis is highly accurate because of…
proofreading enzymes (DNA polymerases)
Translation
RNA –> protein in cytoplasm
