DNA
Euchromatin is DNA that is _____, where chromatin is loosely packed and allows transcription & gene expression
Acetylated
S Phase
What genotype represents an individual who is a carrier for an autosomal recessive disorder?
a) AA
b) Aa
c) aa
d) A
b) Aa
The genotype 'Aa' indicates that the individual has one normal allele and one defective allele, making them a carrier.
Can fathers with an X-linked recessive disorder pass the disorder to their sons?
No
Which type of collagen is crucial for the structure of the basement membrane?
a)Type I
b) Type II
c) Type III
d) Type IV
d) Type IV
Type IV collagen is essential for the structure of the basement membrane/basal lamina, including in glomeruli and the lens.
What is the primary characteristic of heterochromatin?
a) It is loosely packed and accessible for transcription.
b) It contains actively expressed genes. c) It is highly compact and inaccessible to transcription & gene expression
d) It is primarily found in the cytoplasm
c) Heterochromatin is characterized by its highly compact structure, making it inaccessible to transcription machinery, which prevents gene expression.
In which phase do sister chromatids separate?
Anaphase
What is the probability of the children being affected by an autosomal recessive disorder when one parent is homozygous affected (aa) and the other parent is healthy (AA)?
a) 25%
b) 50%
c) 0%
d) 100%
c) 0%
The probability is 0% because all children will inherit one normal allele from the healthy parent and one defective allele from the affected parent, making them all carriers (Aa), but none will display the disorder.
If a mother with an X-linked dominant disorder has two children, what is the likelihood that at least one child will inherit the disorder?
a) 0%
b) 25%
c) 50%
d) 75%
d) 75%
Since each child has a 50% chance of inheriting the affected X chromosome, there is a 75% probability that at least one child will inherit the disorder.
ATP is __________ to provide the energy required for the sodium- potassium pump to move ions against their concentration gradients.
hydrolyzed
What is the rate limiting enzyme in Purine & Pyrimidine synthesis?
Glutamine - PRPP aminotransferase
What step ensures that conditions are favourable for DNA replication?
GI checkpoint
Autosomal ______ Defects include: dystrophia myotonica, Osteogenesis Imperfecta, Marfan Syndrome, Intermittent porphyria, Neurofibromatosis type 1, Achondroplasia, Tuberous sclerosis, Huntington's disease, xWD, familial hypercholesterolemia
Dominant
In X-linked dominant inheritance, how are the affected X chromosomes transmitted from fathers?
a) To all their sons
b) To all their daughters
c) To half of their children
d) Only to their wives
b) To all their daughters
Fathers pass the affected X chromosome to all of their daughters because daughters inherit their father's only X chromosome.
What two conditions are caused by issues with elastin?
Marfan syndrome & emphysema
Marfan: defect in fibrillin-1
Emphysema: alpha-1-antitrypsin deficiency (elastin degrades)
A _____ mutation changes the DNA sequence without altering the amino acid sequence, while a _____ mutation results in a different amino acid sequence
Silent, Missense
Proteins are synthesized from the _ terminus to the _ terminus
N, C
Autosomal ______ Defects include:
Phenylketonuris, Alkaptonuris, sickle cell anemia, cystic fibrosis, Hemachromatosis, Wilson disease, a1-antitrypsin disease, lysosomal and glycogen storage diseases
Recessive (2 copies of recessive gene are needed)
Which x-linked recessive disorder can be triggered by fava beans?
G6PD Deficiency
How many sodium ions are pumped out of the cell during one cycle of the sodium- potassium pump?
a) 2
b) 3
c) 4
d) 5
b) 3
The sodium-potassium pump moves 3 Na+ ions out of the cell during each cycle, which is crucial for maintaining the membrane potential.
What enzyme in DNA replication removes the RNA primers with a unique 5'-3' exonuclease activity?
DNA Polymerase I
Epigenic modifications occur in regions that are rich in what two nitrogenous bases?
cytosine & guanine
Affects gene expression but no DNA alteration
If a heterozygote carrier (Aa) has a child with a healthy individual (AA), what is the probability for the following:
A) normal (AA)
B) carriers (Aa)
C) affected (aa)
A) 50%
B) 50%
C) 0%
What two syndromes are X-Linked Dominant Defects?
Alport Syndrome & Fragile X Syndrome
Which motor protein is responsible for retrograde transport along microtubules?
a) Kinesin
b) Dynein
c) Myosin
d) Actin
b) Dynein
Dynein is the motor protein that facilitates retrograde transport, moving cargo toward the (-) end of the microtubule.