A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped to make possible the evolution of the tetrapod limb. This type of change is illustrative of

TLS Online TPP Program

#Question id: 33234

#Unit 1. Molecules and their Interaction Relevant to Biology

The form of catalysis is often also called nucleophilic catalysis

TLS Online TPP Program

#Question id: 2254

#Unit 2. Cellular Organization

If the intracellular [Ca2+] is 10⁻⁷ mol/L and the extracellular [Ca2+] is 2 × 10⁻³ mol/L, at what potential difference across the cell membrane will Ca2+ be at electrochemical equilibrium?

TLS Online TPP Program

#Question id: 1610

#Unit 4. Cell Communication and Cell Signaling

A polymorphonuclear neutrophil (PMN):

TLS Online TPP Program

#Question id: 11945

#Unit 7. System Physiology – Animal

A patient has the following laboratory values: arterial pH = 7.13, plasma HCO3− = 15 mEq/L, plasma chloride concentration = 118 mEq/L, arterial Pco2 = 28 mm Hg, and plasma Na+ concentration = 141 mEq/L. What is the most likely cause of his acidosis?

TLS Online TPP Program

#Question id: 196

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is correct about S-adenosylmethionine (SAM) is formed from the amino acid methionine so that

A) methyl groups can be formed.

B) it can react with nucleophilic acceptors.

C) it can donate methyl groups in many biosynthetic reactions.