Cycle 5 Flashcards
Are transposable Elements
Present in plant cells? Do they undergo transposition?
YES
When they do, they can interfere with a gene for example one that is involved in the ____________ of pigment production, and so the pigment is either produced or not produced (that is how u get different colors in the corn or kernel)
biosynthetic pathway
___-____% of human genes contain TEs (up to 1000 per gene)
70-80
TE: In the ______ region
intron
Not interfering with ______
splicing
Most TE are “____” due to inactivating mutations (cannot undergo transposition)
dead
The effect varies from _______ to ______
negligible to disease
Active TEs have evolved to insert into “____ ____” in the genome
safe havens
Genes produce ______ that inhibit jumping
proteins
The host _____ (inactivates) most active TEs
silences
What do transposable Elements do (what happens if they jump)? (2)
-TE lands in non-coding (safe haven) regions
-TE lands in a protein-coding gene:
Insertions can lead to disease-causing mutations (ex: _____ when no one in the family has a history)
hemophilia
HOW?
-Transposable element interferes with factor 8 gene
-This factor produces a protein involved in clotting your blood
L1 (type of TE that goes and inserts itself in the factor 8 gene by a transposition event)
-Therefore clotting gene is not funcitinobale
Insertions can also lead to gene ______
shuffling
HOW?
-Each gene has its own promoter
One promoter can activate more than one gene
Ex: promoter one is specific for Gene 1 and Gene 2, it activities they, promoter two is specific for Gene 3 and Gene 4
When TE lands in the region
Can leave part of its sequence in that original region and jump
The second thing it can do is take part of the sequence with it
OR third, take the entire gene with it
Inference causes nonfunctional protein
If TE is cut and pasted then gene 1 will be in control of the wrong promoter
Promoter determines expression
Gene 1 is now regulated under a different promoter
Now gene is transcribed and translated at the incorrect rate
___ elements cause disease
Most common TE
Has the ability to jump
Alu
List of mechanisms to generate genomic variation
DNA polymerase
Non-homologous End Joining
Slippage
Tautomeric shifts
Transposition
__________ makes errors as it adds bases during DNA synthesis
DNA polymerase
Sloppy mechanisms to repair double-strand breaks caused by ionizing radiation
Non-homologous End Joining
InDel mutation
Forward ______ on the template strand leads to deletion
Backward ______ on synthesized strand leads to insertion
Slippage
Spontaneous shift in the chemical form of nitrogenous bases changes preferential pairing
T and G shift from dominant keto form to rare enol form
A and C shift from domina amino to rare imino form
Tautomeric shifts
Cut/copy and paste transposable elements mostly between genes
More transposable elements are found in larger genomes
Transposition
______ was the first to pioneer how phenotypic expression is a result of different genes or alleles interacting with one another
Gregor Mendel
he used pea plants because (3)
-Fast generation time
-Easy to manipulate the peas
-Didn’t have scientific tools back in the day, relying on the naked eye (observable phenotype)
he concluded:
You need ___ alleles for one trait (mendelian form of inheritance)
2
Most of our inehetricen now are nonmendelian, but in fact, are ______ (many genes give rise to a specific phenotype)
polygenic
_______: The dominant one will express the phenotype
Heterogsyous
At the genetic level, what is the difference between a dominant vs receive allele?
At the DNA level: the sequence is different
______ in DNA means the gene is being transcribed and RnA is being made
Expression
Expression in _____: whatever is happening in the cell, the phenotype being expressed on the organism (color, shape, etc)
phenotype
T/F A recessive allele means it is not being expressed in the cell
FALSE: A recessive allele doesn’t mean it is not being expressed in the cell
Phenotypic expression is being masked by the gene, therefore _____
dominant
Neither one of them is dominant and recessive, both are dominant
Both fully express their phenotype
Bloodtype is example
Codominance
Neither allele can express its complete phenotype
Intermediate expression
Gregor Mendel used _____ Crosses
Controlled
Mendel’s Conclusions:
Variation in traits is due to _____ alleles
Alleles segregate _____ into gametes
Organisms inherit ___ alleles for each trait
Appearance of heterozygous is determined by _____ alleles
different
randomly (Law of random segregation)
two
dominant
_______ Crosses Consider One Trait and Predict Distribution of Offspring
Monohydbrid
_____: Is a form of non-Mendelian inheritance in which one gene is capable of interfering with the expression of another
Epistasis
Alleles of two Genes Assort Indepnendlty in _____ Crosses
Dihybrid
Depending on the _____ that your alleles express will determine what it can do in the cell which will determine the phenotype
version
The _____ Gene plays a Role in Eye color
OCA2
An example of ________ inheritance and interaction of different genes to produce a phenotype is eye color
non-mendelian
OCA2 allele has different versions, One gets transcribed and translated into “__ protein”
p
P protein is involved in the maturation of:
melanosomes
Melanosomes are organelles inside your cell (in stroma) that produce and store ____
melanin
_____ is a pigment that gives the dark color appearance
Melanin
Less melanin = ____ phenotype
lighter
People with brown eyes are producing more __ protein
p
If you have blue eyes, then you have a different verison of OCA2 which results in ____ production of P protein
less
Absorb light and reflect in specific ways (how ____ scatters light why eye color can change in the sun)
protein
____ activates OCA2
Nonfunctional in blue eyes
Black and red are two extremes
HERC2
People have different colored eyes based on whether you’re making melanin or not and the ____ of melanin
degree
Another part is the other genes that are involved in eye color
They produce protein which absorbs _______ from visible light in a very specific way
wavelength
_____ Disease is an Example of Incomplete Dominance in Humans
Tay Sachs
T/F Sometimes melanocyte maturation can continue after birth that’s why eye color can change through the years
TRUE
Two Incompletely Domainnt Allee Lead to an _________ Expression
Intermediate
__ cannot make Hex A, therefore
rr enzyme cannot work
r
_____ is a key enzyme that lysosome in brian depends on
Hex A
Fatty structures accumulate in the brain, All molecules in the cell have to _____
recycle
______: organelle that does the recycling
Lysosome
We all have the same except the last ________, which determines blood type
terminal sugar
______ Alleles are Equally Expressed in Heterozygotes
Codominant
_______ is the enzyme
Forms glycosidic bonds
Add specific types of sugars
Glycocyltrangerase
Alleles are located in the ___ chromosomes
sex
Blood type is an example of:
Codominant alleles
We code for the ____ that adds the last terminal sugar
enzyme
______ Characteristics Follow Different Inheritance Patterns in Males and Females
Sex-Linked
_______: a gene that you will inherit/cause the disease is on the x chromosome
X-linked disorder
_____can be carriers because they can have one still that is fully functioning
Females
If X linked ______ then one would be enough
dominant
X linked Recessive means you’d need two ______ to be affected
bad copies
____ cannot be carriers because if they have affected X then they have the trait
Females
If trait is _____: then both will behave similarly
dominant
FOR _______ (nonsex chromosomes), the probability is half (25% compared to 50%)
AUTOSOMAL
Sex-linked chromosomes have a higher probably of appearing in offspring than _____ disorders
autosomal
-Colour blindness is _____, men have more chance
x - linked
Monohydbrid: __:___ phenotypic ratio
3:1
Dihybrid: ::_;_phenotypic ratio
9:3:3:1
ABO blood types based on surface ______
antigens
