Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 16 Genetics (Replication of DNA (occurs before (nuclear division,…
Chapter 16 Genetics
Replication of DNA
occurs before
nuclear division
mitosis
meiosis
replicated during
S phase of cell cycle
chromatin becomes less compact
one strand of DNA helix cut
free nucleotides diffuse
polymerized into short primer RNA
act as substrates
for DNA synthesizing enzyme
called DNA polymerase
about 10 nucleotides long
Adds deoxyribonucleotides onto
end of primer RNA
method is known as
1 more item...
to regions of single DNA
pair with bases along both strands
form a replicon
is a small bubble
where 2 strands seperate
from each other in
small region
replication fork
DNA coils and separates
has forked appearance
runs into one of
adjacent replicons
then new pieces of DNA
are litigated
into two new
Concepts
genetics
science of inheritance
chemical basis
gene
occur in multiple forms
known as alleles
arise from mutation
new nucleotide sequence
sequence of DNA nucleotides
guides construction of
RNA
proteins
more copies of genes
Genotype
alleles that a single individual has
expression of alleles determine
size
shape
metabolism
also called phenotype
Selective Advantage of Reproduction
sexual
organisms combine alleles with
one another
produces
possibly better individuals
increases chance of
alleles surviving
more resistant offspring
asexual
each offspring
identical to
parents
siblings
have same
DNA
alleles
only adapted for
parent's environment
not adapted well to
stressful environments if
parents are not
Mutations
any change in DNA
smallest mutation
called point mutation
Portion of DNA lost
called deletion
Addition of extra DNA
called insertion
DNA breaks and
is repaired in reverse
called inversion
Causes of Mutations
mutagen
something that causes mutations
examples
certain chemicals
ultraviolet light
X-rays
radiation
nitrous acid
reacts with cytosine
forms uracil
gives DNA G-U base
instead of G-C base