8/14 PALS Session (Rahul & Saad)

What single strand DNA repair mechanism is defective in xeroderma pigmentosum?

• Base excision repair

• Nucleotide excision repair

• Mismatch repair

• Homologous recombination

True or False: DNA polymerase III and I are only in prokaryotes

• True

• False

Which of the following is FALSE about chromatin?

• Found in nucleus of eukaryotic cells

• Chromatin condenses into chromosomes

• Histones have negative charge (acidic amino acids)

• H1 histone creates and stabilizes condensed chromatin

Which of these embryonic genes is responsible for segmental organization in cranial-caudal direction & transcription factor coding?

• Sonic Hedgehog Gene (SHH)

• Wnt-7 gene

• Fibroblast growth factor (FGF) gene

• Homeobox (Hox) genes

How many chromosomes are there in each cell after Meiosis I?

• 46

• 23

• 92

• 72

Tags

NGSS.HS-LS3-2

What clinical manifestation can HOX gene mutations (HOXA1, HOXB1, etc) cause?

• Holoprosencephaly

• Polydactyly/ Syndactyly

• Hyperpigmented macules

• Diarrhea & blood in stool

Tags

NGSS.HS-LS3-2

Purpose of cholesterol in plasma membrane

• At high temperature, it keeps membrane fluid

• At low temperature, it keeps membrane fluid

• At high temperature, it keeps membrane neutral

• At low temperature, it keeps membrane stiff

Which of these is variable expressivity?

• Patients with the same genotype have varying phenotypes

• Not all individuals with a disease show the disease

• One gene contributes to multiple phenotypic effects

• Increased severity or earlier onset of disease in succeeding generations

Which ion has a higher concentration inside the cell (contributes to the resting membrane potential)?

• Sodium ion (Na+)
• Potassium ion (K+)
• Calcium ion (Ca2+)
• Chloride ion (Cl-)

Which transport allows larger molecules/polar molecules to move across the cell membrane using channels and carrier proteins?

• Osmosis

• Facilitated Diffusion

• Primary active transport

• Secondary active transport