<span>R group (or side chain) is an organic component of amino acids that is unique to each amino acid. </span> <span>Three of the amino acids have basic side chains at neutral pH: arginine (Arg), lysine (Lys), and histidine (His). Their side chains contain nitrogen and resemble ammonia, which is a base and their pKa's are high enough that they tend to bind protons, (positive charge). Aspartic acid or aspartate (Asp) and glutamic acid or glutamate (Glu) are acidic amino acids because their side chains have carboxylic acid groups whose pKa's are low enough to lose protons, (negatively charged). The non-polar amino acids contain uncharged functional groups<span> at physiological pH and are incapable of participating in hydrogen bonding. </span></span>
First eliminate choices C and D since they both mention that fact 1 is crossing over ( which is also referred to as genetic recombination) . So you're left with A and B and the correct answer is B .
Answer:
they tend to run more smoothly and on schedule;
not having a human on board to deal with unexpected problems
Explanation:
I just had the same one
Cyanobacteria, also known as blue-green algae, are found in vast quantities in fresh and salt water. Cyanobacteria are able to conduct photosynthesis. By utilising energy from the sun, they produce carbohydrates from water and carbon dioxide. As a byproduct, they produce oxygen. So cyanobacteria provided oxygen to the atmosphere that allowed other lifeforms to develop.
