Genetics Stuff.
Even More
Genetics
Stuff
Yet More Genetics
Stuff.
Still, Yet, Even
More Genetics
Stuff
Astrophysics…
Ummm…actually it’s
More Genetics Stuff
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What do skin
color, hair color,
and eye color
have in common?
They are multiple genes traits
(they’re determined by
MULTIPLE genes).
How are mitosis and meiosis
similar? How are they different?
2.
3.
4.
5.
Mitosis
1. Asexual
Body cells (occurs in all
organisms)
Prophase, metaphase,
anaphase, telophase
Results in two daughter
cells.
New cells have normal
number of chromosomes
(2N-diploid)
6. New cells fully
functional
Meiosis
1. Sexual
2. Gametes (animals and
plants)
3. Prophase, metaphase,
anaphase, telophase…twice!
4. Results in four daughter
cells.
5. New cells w/ ½ normal
number of chromosomes
(N-haploid).
6. New cells need to combine
with another gamete before
they’re fully functional.
Using bacteria to produce human
insulin is an example of______?
Genetic Engineering.
Colorblindness is a sex-linked
recessive trait. What do the
genotypes of each parent of a
colorblind child have?
Why do males have a greater
chance of being colorblind?
At least one recessive allele.
The allele is linked to the X
chromosome. Males are XY. If a
male gets the recessive allele there is
no chance of getting a dominant
allele that will mask it.
What happens to cause Down
syndrome?
One of the chromosome fails to
separate properly during meiosis
(meiotic disjunction). This results in
one extra chromosome in pair #21.
This is known as TRISOMY 21.
What causes genetic disorders
such as sickle-cell anemia?
Mutations.
What is a pedigree?
A chart that tracks the occurrence
of a trait in a particular family.
What is hemophilia?
A genetic disorder that prevents
blood from clotting the way it
should.
Sex linked disorder
What is cystic fibrosis?
An autosomal recessive genetic
disorder that causes a protein
malformation. It results in thick
mucus in the lining of the lungs
and intestines and frequent (and
resistant) bacterial infections.
What is the term for a picture of the
chromosomes in a cell?
• A Karyotype.
What is the difference between
incomplete dominance and codominance?
Incomplete Dominance:
R=Red flowers, r=white flowers
Rr=pink flowers rather than red.
Co-dominance:
R=Red flowers, r=white flowers
Rr=flowers with patches of red and
patches of white.
What is the difference between
inbreeding and hybridization?
Inbreeding: crossing two individuals
with identical or similar alleles to produce
specific traits. This can increase the
chance of inheriting genetic disorders
Hybridization: crossing two individuals
with different traits, so offspring
might get the best traits of both. Used in
agriculture.
What is cloning?
A procedure that produces an
organism that is genetically identical
to the parent.
Can environment affect phenotype?
Explain.
YES! You may be
genetically predisposed to
be 6’4” tall, but without the
proper nutrition…ain’t
gonna happen!
What genetic disorder is
characterized by abnormally
formed hemoglobin ?
Sickle-Cell Anemia!
What does the notation Rr mean to a
geneticist?
One dominant and one recessive
allele.
This genotype is also known as
heterozygous or hybrid.
What do homozygous and
heterozygous mean?
Homozygous means two of the same
alleles.
Heterozygous means one recessive
and one dominant allele.
What is the difference between a
genotype and a phenotype?
Phenotype = the physical
(sometimes) visible traits of an
organism (example: blue eyes, type
AB blood).
Genotype = the genetic make-up of
an organism…its chromosomes
(example: Bb, BB, bb).
Explain the relationship among
DNA, chromatin, chromosomes,
genes, alleles, and traits.
DNA is the molecule that codes for
heredity. Normally it is in the form
of chromatin, but during cell
division it forms structures called
chromosomes. A gene is a specific
part of a chromosome that is
responsible for a certain trait.
Alleles are the various forms of
expression for a given trait.
If a heterozygous parent is crossed
with another heterozygous parent,
what is the probability that the
offspring will be homozygous
recessive?
1:4 or 25%
What is a purebred?
Homozygous dominant
or
Homozygous recessive)
What is the chromosome theory of
inheritance?
Genes are passed from parents to
offspring on chromosomes.
What is a pedigree?
What do the various shapes and
shading on a pedigree represent?
A pedigree is a chart that shows
how traits are passed from one
generation to another.
Open Circle = Normal Female
Half-shaded Circle=Carrier Female
Shaded Circle=Affected Female
Open Square = Normal Male
Half-shaded Square =Carrier Male
Shaded Square =Affected Male
If you have the A and B alleles for
blood type, what type blood do you
have?
AB
Are males XX or XY?
XY