Answer:
D. A mutation causing uncontrolled cell division
Explanation:
Cell division is controlled by various mechanisms. Any mutations in the genes regulating the cell division lead to uncontrolled cell division. Loss of control over the process of cell division leads to the formation of tumors.
These tumors may cause cancer if they are transformed into malignant tumors. Hence, a mutation that causes loss of control over cell division is harmful.
Answer:
A single phospholipid molecule has a phosphate group on one end, called the “head,” and two side-by-side chains of fatty acids that make up the lipid “tails. ” The phosphate group is negatively charged, making the head polar and hydrophilic, or “water loving.” The phosphate heads are thus attracted to the water.
Explanation:
The primary products of the light independent reactions (after one turn of the cycle) are:
a) two G3P molecules
b) three ADP
c) two NADP+
However ADP and NADP+ are not really "products". They are regenerated and later used again in the Light-dependent reactions. Each G3P molecule is composed of three carbons.
For the Calvin cycle (Light independent cycle) to continue, 5 out of the 6 carbons provided by the two G3P molecules are used to regenerate ribulose 1, 5 phosphate. Therefore there remains only one carbon for the next turn of the cycle.
One molecule of glucose requires 6 turns of the cycle. Any extra G3P is used to make starch, sucrose and cellulose.
