sex linked and disorders
DESCRIPTION
Sex Linked and disorders. Mendel. Varied Types of inheritance. Epigenetics. Misc. Organisms that have two different alleles for a trait are called …. ANSWER:. Heterozygous. Name three things a Punnett square can show. ANSWER:. Genotypes of parents Possible results of the cross - PowerPoint PPT PresentationTRANSCRIPT
Sex Linked and disorders
Mendel Varied Types of inheritance
Epigenetics Misc
Organisms that have two different alleles for a trait are
called …..
ANSWER:
Heterozygous
Name three things a Punnett square can show
ANSWER:
Genotypes of parents
Possible results of the cross
Possible genotypes of the children
Explain complete dominance
ANSWER:
When the dominant allele is present the recessive
allele is masked
Achondroplasia (dwarfism) is caused by a dominant gene. A woman and a man both with
dwarfism marry. If homozygous achondroplasia results in death
of embryos, list thegenotypes and phenotypes of all
potential live-birth offspring.
ANSWER:
2 Aa Dwarfism
1aa Normal
What type of dominance allows all alleles present to be fully
expressed?
ANSWER:
Codominance
In a family of four, 1 child has curly hair, 1 child has straight hair, and 2 children have wavy hair. Show what the genotypes and phenotypes of the parents
would have to be.
What kind of dominance is this?
ANSWER:
Parent 1 – genotype Cc
Phenotype – wavy hair
Incomplete dominance
Two newborn babies were accidentally mixed up at the
hospital. Determine the parents of the babies by blood type.
ANSWER:
Baby 1 Brown
Baby 2 Smith
What type of inheritance is shown by human skin color, height, eye color, etc.?
ANSWER:
Polygenic
What is the difference between multiple alleles and polygenic
inheritance
ANSWER:
Multiple alleles – one gene has more than 2 variants or alleles for a trait
Polygenic – multiple genes ( can be on multiple chromosomes) all
interact to produce a phenotype
Do men or women express sex linked traits more often?
Why?
ANSWER:
Men, they have one X chromosome, thus they only need one recessive
and it is expressed
What are genetic test performed on? (What are valid samples?)
ANSWER:
Blood
Skin
Hair
Amniotic fluid
If you mutate a sequence of DNA which do you alter?
GenomeEpigenomeProteome
ANSWER:Genome
Why can an organism produce more proteins than they have
genes(Ex 20,000 genes and 120,000
proteins)
ANSWER:
Proteins are made up of various combinations of polypetides
Genes code for primary structure
Also modification after transcriptions allows RNA to be “modular” in
function
If two people who are both carriers for a genetically
inherited fatal recessive disease decide to become parents, what
will be the odds that their children will also be carriers?
ANSWER:
50% or 2 out of 4
What attaches to the strand of DNA to inhibit transcription of the gene
ANSWER:
A methyl group or acetyl group
When is the epigenome silenced?
ANSWER:
During the first days after an egg is fertilized
How are histones manipulated to loosen them up and allow the DNA
to be transcripted?
ANSWER:
Acetyl or methyl groups attach to them and the
negative charges repel or attract the histones away
from each other
DAILY DOUBLE
If the human genome is like a computer, what is the epigenome
like?
ANSWER:
Computer Software
The alleles for eye color and for body color are on the X chromosome of
Drosophila, but not on the Y. Red eye color (w+) is dominant to white eye color (w), and tan body color (y+ ) is
dominant to yellow body color (y). What is the genotype of a tan-bodied, white-
eyed male?
ANSWER:
In horses, coat color is often codominant. The chestnut horse carries two chestnut alleles (Cc)The palomino horse carries on chestnut allele (Cc)and one crème allele (Ccr). A horse with two crème alleles is called a cremello. A. If you were to breed a chestnut horse with a palomino what would the offspring be like?
B. What are the possible combinations of parents to get a cremello horse?
ANSWER:A. Chestnut (CcCc)Xpalomino(CcCcr)
50% Chestnut 50% Palomino
B. Cremello X Cremello 100% Cremello
Palomino X Cremello 50% Cremello
Palomino X Palomino 25% Cremello
In a dihybrid cross, the expected ratio in the F2
generation is..
ANSWER:
9:3:3:1
Epigenetics is critical to what process that occurs during very early development of the fetus?
ANSWER:
Cell differentiation
What is a test cross?
ANSWER:
A cross between an dominant phenotype and a
recessive phenotype to determine the genotype of the dominant phenotype
If two parents are heterozygous for a genetically inherited dominant trait, what is the probability that
they will have a child together who has this trait in his or her
phenotype?
ANSWER:
75%
If there is a single pair of alleles that determine the number of toes for an
animal species and homozygous dominant individuals have 8 toes,
heterozygous ones have 7, and homozygous recessive ones have 6, the inheritance pattern would be referred
to as:
ANSWER:
Incomplete dominance
FINAL JEOPARDY
Baldness in humans is a dominant, sex-influenced trait. This gene is on the autosomes, not the sex chromosomes, but how it is expressed is influenced by the person’s sex (due to hormones present, etc.). A man who is BB or Bb will be bald and will be non-bald only if he is bb. A
woman will only be bald if she is BB and non-bald if she is Bb or bb (it’s almost like B is dominant in males and b is dominant in females).
Actually, because of the influence of other sex-related factors, most women who are BB never become totally bald like men do, but rather,
their hair becomes “thin” or sparse. If two parents are heterozygous for baldness, what are the chances of
their children being bald? Use a Punnett square to illustrate this.
Note: because the sex of a person does make a difference in how the gene is expressed, you need to set this up as a dihybrid cross to account for the
sex of the children.
ANSWER:
1/8 of the children will be bald daughters, 3/8 will be normal daughters,3/8 will be bald sons1/8 will be normal sons;
.