The correct answer is (2) - Stratosphere.
Ozone is found in the stratosphere , a layer beginning between 6 and 10 miles above the earth's surface and extends upward to about 30 mile above the surface of he earth.
The ozone that is found in the stratosphere absorbs most of he harmful ultraviolet sunlight and is thus called the "good ozone"
Ozone is also found in the lower region of the atmosphere known as the troposphere. But the ozone here strongly reacts with molecules causing toxicity in plants. The ozone is therefore termed as "bad ozone."
Answer:
X is negative heterotropic modulator
Explanation:
In allosteric regulations, modulators are molecules that causes a change in the conformation of an enzyme, hence, resulting a change in enzyme activity. It can lead to a decrease or an increase of the enzyme. When a molecule decreases the enzyme activity it called a negative modulator, when it increases or activates the enzyme activity, it is called a positive modulator.
A positive or negative modulator can either be homotrophic (substrate acts as modulator) or heterotropic (another ligand acts as modulator).
In the example above, X is negative heterotropic modulator, because the modulator is different from the substrate and it also decreases the enzyme activity.
Water has special characteristics because liquid water is denser than ice and ice floats on top of liquid water.
Answer: Option A & D
<u>Explanation:</u>
A water molecule is formed by the covalent bonding between two atoms of Hydrogen atom with one atom of Oxygen. In water, the Hydrogen bonds are the one that keeps the water molecule intact.
When the water molecule freezes the bonding becomes weak as they are separated and set apart which makes the liquid water denser than ice. Normally a substance floats if it is less dense. Ice floats because it is less dense than water.
Tumor suppressor genes encode for proteins that inhibit or slow the progression of the cell cycle through a specific stage.they also encode for check point control proteins that arrests the cell cycle if the DNA is damaged or the chromosomes are abnormal. Mutation in the tumor suppressor genes that cause a loss or decreased function would lead to uncontrolled cell cycle leading to abnormal proliferation and the cell may become cancerous.