Answer:
Imagine that NASA discovered a prokaryote-like organism. Initial experiments indicated they use the same DNA → RNA → protein system as life on Earth, except that
there are only 2 bases (A and T) in the Martian DNA, and
there are only 17 amino acids found in Martian proteins.
Based on this information, what is the minimum size of a codon for these hypothetical organisms?
Explanation:
Answer:
Option B. A double-stranded molecule with coded instructions for anorganism's physical characteristics, is the correct statement.
Explanation:
DNA is a genetic material which contains information about the physical features and characteristics of an organism. It is composed of five carbon sugar, phosphate group and nitrogenous base. The DNA base are adenine, cytosine, guanine, and thymine.
Answer:
A. Molecular changes such as extracellular signals on extracellular ligands can result in quick changes in cell behaviour. One example is insulin. Upon insulin binding on the receptor on the cell membrane, the cell release GLUT4 transporters (for muscle cells) to increase uptake of glucose.
B. Slow changes in cell behaviour can be observed for other lipophilic hormones or intracellular receptors such as glucocoortoid or estrogen which reacts with receptors in the cells.
C. Insulin is required to maintain a constant blood glucose level and hence levels of insulin has to be mediated in correspondence to the blood glucose levels. Fast acting signalling is thus required for homeostasis of blood glucose levels. Where for such lipophilic hormones such as steriods, glucocortoid, these hormones tend to have a longer lasting effect and hence results in a slow change.
Answer:
Explanation
Water in a lake freezes from the bottom up, killing most aquatic organisms. When water in a lake freezes, it floats, providing insulation for organisms below. ... If water were most dense as a solid, lakes would freeze from the bottom up, eventually freezing solid.
