If the S-A node discharges at 0.00 seconds, when will the action potential normally arrive at the AV bundle (bundle of His)?

#Question id: 17079

#SCPH01 Biochemistry

#Question id: 4955

#SCPH06 I Botany

If relatively small carbonaceous chondrites from space were a significant source of Earthʹs original amino acids, then which two of these would have been most important in permitting their organic materials to survive impact with Earth?

I. Carbonaceous chondrites must contain no D-amino acids.

II. Earthʹs early atmosphere must have had little free oxygen.

III. The chondrites must have arrived on Earth before 4.2 billion years ago.

IV. Earthʹs early atmosphere must have been dense enough to dramatically slow the chondrites before they impacted.

V. The chondrites must have impacted land, rather than a large body of water.

#Question id: 16073

#SCPH05 I Biotechnology

#Question id: 3635

#SCPH01 Biochemistry

In the multiple allele series that determines coat color in rabbits, c+codes for agouti, cch for chinchilla and ch for Himalayan. Dominance is in the order c+>cch>ch. In a cross of c+/cch X cch/ch, what proportion of progeny will be chinchilla?

#Question id: 3688

#SCPH28 | Zoology

Which of the following enzyme has a unique ability to introduce positive and negative supercoiling of the DNA and it is the target for antibacterial agents such as ciprofloxacin/quinolones?