Download Unit VII: Genetics

Unit 6: Chapters 23, 24, & 25:
Genetics
Basic Genetics
Modern Genetics
Understanding our genes and the ways
they are passed to the next generation.
A. Basic Genetics
_________________ = study of heredity
understanding of how ______________ get ________ from
___________________, _____________________
1. Traits = characteristics
hair color, eye color, widows peak, tongue rolling, ear lobes
2. Gene Chromosome Theory
- ________________________________________
found in the nucleus
- Because of ______________________
(2 of each chromosome)
______________________________
__________________________ called
_____________________
- Remember that through meiosis each parent only passes
on __________________________
- Through fertilization the ____________________ of genes
is restored
- Organisms can have
____________________ 
the __________________
_________________ of the
organism
3. _______________________________________________
When ___________________________________ there is a
____________________________________ on homologous
chromosomes.
______________________________________________.
As a consequence, _________________________ are likely
to be produced.
4. _____________________________________________
_________________________________________________
__________________ (nonhomologous chromosomes), they
_______________________________ and, therefore, may be
______________________________ of each other. (not linked)
5. ________________________________
__________________________________________. The
__________________________________________________.
6. Probability and Inheritance
a) _____________ = genetic make up / ___________ of an
individual
______________ = same alleles (TT or tt)
______________ = different alleles (Tt) = Hybrid
b) ____________ = ___________________ (Tall or Short)
Usually _______________________ – sometimes the
______________ can affect the phenotype.
Can two organisms have the same
phenotype but different genotypes?
c) Punnett Square
representation of _____________________ and the different
_____________________________________
ex: Cross: Homozygous Tall x Homozygous Short
1. Determine the genotypes of
the parents
2. Determines the possible
gametes of the parents
3. Write the gametes on the
outside of the box
4. Combine the parents
gametes
Remember only 1 gamete
from each parents
All the offspring are genotype Tt – heterozygous
The genotype tells the phenotype – Tt  Tall
In the heterozygous the recessive allele is hidden
ex: Cross: Heterozygous Tall x Heterozygous Tall
What is the genotype ratio?
What is the phenotype ratio?
Through his knowledge of
math and detailed record
keeping, with 10,000s of pea
plants Gregor Mendel always
had this ratio in the
phenotypes.
B. Human Inheritance
a) ________________
- a diagram of family
relationships that uses
symbols to represent
people and lines to
represent genetic
relationships.
- easier to visualize
relationships within
families
- Pedigrees are often
used to determine the
mode of inheritance
(dominant, recessive, etc.)
of genetic diseases.
b) Human Genetic Diseases / Disorders
1) _______________
recessive allele
lack pigment in skin, hair, eyes
2) ________________
recessive allele
excess mucus in lungs;
increases susceptibility to infections;
death in childhood unless treated
3) ___________________
recessive allele
accumulation of phenylalanine
(amino acid) in tissue
body can not break down the
amino acid
mental retardation if they eat
phenylalanine
4) _________________
recessive allele
higher occurrence (1/100 vs
1/100,000) in Jewish families
of eastern European ancestry
lipid accumulation in brain
cells, nervous system break
down  death in early
childhood
5) ______________________
dominant allele
bones fuse and stop growth
6) ______________________
codominant allele
red blood cells have a crescent
shape
misshapen hemoglobin
can not carry O2 as well
7) ____________________
dominant allele
extra toes and fingers
not always expressed
8) ______________________
chromosomal disorder
extra 21st chromosome cause
by nondisjunction
C. Modern Genetics
1. _____________________ – 1950’s
Used Rosalind Franklin’s x-ray pattern
of DNA to build its 3-D structure
Double helix with complimentary
base pairs
a) DNA Structure
__________________
A = ________________
B = ________________
C = ________________
A–T
G–C
__________  _______  _____________
From the human to the DNA – PBS Flash
DNA
STRUCTURE
MOVIE
2. DNA Replication
a) Occurs inside the __________________
b) DNA molecules ____________________, then produces
_______________________________________________
_________________
c) Each original strand serves as a template for the new
strand
Original DNA
DNA “Unzips” Enzymes fill in nucleotides
TAC
A
AT
TG
G
CGG
G
GC
CC
C
ACC
T
TG
GG
G
CGT
G
GC
CA
A
AGG
T
TC
CC
C
C AA
G
GT
TT
T
TAG
A
AT
TC
C
TAC
CGG
ACC
CGT
AGG
C AA
TAG
Easy Version of DNA Replication
Check out this site on your own for a more detailed
explantation
More Complicated but explains the process really well.
http://207.207.4.198/pub/flash/24/menu.swf
3. Protein Synthesis
a) RNA = ___________________
_________________ nucleic acid
contains Ribose as the sugar not __________ as in DNA
has the base ________ instead of _________ as in DNA
Types of RNA
______ = ______________ 
carries gene out of the nucleus
rRNA = ribosomal RNA 
makes up ribosome
______ = ______________ 
brings in amino acid
b) Transcription
1st step of protein synthesis; similar to replication
_________________________
Occurs in the ______________
“Unzip” DNA – uses 1 side of DNA as a template
RNA polymerase fills in complimentary RNA bases
mRNA detaches from DNA
mRNA leaves nucleus
Simple Trasncription Animation
Just another Trancription animation
Original
DNAEnzymes
DNA
“Unzips”fill inRNA
RNA
DNA
breaks
nucleotides
reconnects
from DNA
TAC
A
AT
UG
G
CGG
G
GC
CC
C
ACC
TG
U
GG
G
CGT
G
GC
CA
A
A G G C AA TA G
T
UC
CC
C G
G TUTU AATUCC
The groups of 3 bases on the mRNA is called a CODON
The codon codes for specific amino acids when making a
protein
c) Translation
2nd step of protein synthesis
__________________________________________
occurs in the ______________ at the _______________
_____________________________________
Matches the _______________________________
________ reads next _____
and brings in next tRNA with
matching anticodon
Since _____ is attached to
________ – two amino acids
are located next to each
other
This proximity allows the
________________
Makes a _____________
Repeats until mRNA says
stop
More than 1 ribosome can attach to the mRNA at a time
Makes multiple peptides
Translation Animation
d) Protein Synthesis Overview
To see it in some more
detail check out the
following website on
protein synthesis
http://learn.genetics.utah.edu/content/begin/dna/
e) Genes code for peptides
generally a protein is the
combination of more than
1 peptide
Try this website as an interactive for
replication and protein synthesis
http://www.pbs.org/wgbh/aso/tryit/dna
/shockwave.html
4. Mutations
Changes in the DNA sequence
Some are good
Some are bad
Most are neutral
Mutations are only passed to the next generation if they occur in gametes
Mutations in somatic cells are not passed – acquired characteristics are not
passed
a) Gene Mutations
changes in a single gene
1) Point Mutations – involve just one nucleotide
substitution = change one nucleotide for another
ex:
TAC G C G AC C C GA
becomes
TAC G C C AC C C GA
the change may or may not change the amino acid
2) Frameshift Mutations
insertion or deletion of a single nucleotide
changes the codons read by the ribosome
usually affects all amino acids after the mutation
ex: DNA:
TAC C G G AC C C GA
mRNA:
AUG GCC UGG GCU
Amino A:
Met
Ala
Try
Cys
Insertion
DNA:
TAC G C G
GAC CCG
mRNA:
AUG CGC
CUG GGC
Amino A:
Met
Arg
Leu
Gly
A
U
The order of amino acids changed  changes protein (big
time)
Ex:
delete 1 letter
THE FAT CAT ATE THE RAT 
THE FTC ATA TET HER AT ????
Completely change everything after the deletion
No longer makes sense
The same thing happens with the protein
The order of the letter (amino acids) determines the structure of the
words and sentence (protein)
One little mistake can completely change the meaning
b) Chromosomal Mutations
changes the structure of a chromosome
rearrange the genes on a chromosome
1) _______________________
2) _______________________
3) _______________________
4) _______________________
Chromosomal
Mutations
c) Mutagenic Agents
factors that cause mutations
1) ___________________ –
X-rays
_________________
radioactive substances, and cosmic rays
2) ______________ –
formaldehyde, benzene, asbestos fibers
_______________
_______________
D. DNA Technology
ways in which the knowledge of DNA can help benefit
society
a) _________________________
__________________ in organisms, mating the organisms,
and hoping some of the offspring have the combinations of the
traits
ex: dogs,
cattle, crops
selective breeding
has been occurring
for 1000s of years
b) ______________________________
__________________; transfer DNA from one organism to
another
isolate gene 
____________________________ 
_____________________________ 
place recombinant DNA in a new organism
*restriction enzymes = cut DNA at very specific sequences
can be used to make a variety of products
c) ________________
making an _______________
Remove the nucleus of an egg cell
Use the nucleus of a body cell 
Insert the nucleus into the egg cell 
Grow the egg cell 
Identical genetic copy of the body cell
organism
Click and Clone
d) ________________________
making “__________________”
use restriction enzyme to cut DNA
into fragments 
place DNA into a porous gel 
electrify gel and DNA fragments
move 
small pieces move the farthest 
Gel Electrophoresis - Learning Center
Gel Electrophoresis Virtual Lab
e) Human Genome Project
sequence all human DNA
map and locate all the
human genes  about
3,000,000,000 base pairs in
order
help to find and cure diseases
Gene Therapy
find defective gene and
replace it with a healthy gene