<span>achievement
</span>A test that measures a person's knowledge in a specific subject area is a(n) achievement test.
Answer:
A glance of earth taken from space will depict it blue. This blue colour is actually water, the major part of the earth is covered with water. We need water for almost everything, for example- drinking, bathing, cooking etc and therefore we should know about the properties of water. 65 % human body is composed of water. Water is essential for the survival of life on earth. Water is distributed unevenly on the earth’s surface. It forms a major solvent and dissolves almost every polar solute. So let us have a look at its properties.
Physical properties of water : Water is a colourless and tasteless liquid. The molecules of water have extensive hydrogen bonds resulting in unusual properties in the condensed form. This also leads to high melting and boiling points. As compared to other liquids, water has a higher specific heat, thermal conductivity, surface tension, dipole moment etc. These properties form the reason for its significance in the biosphere. Water is an excellent solvent and therefore it helps in the transportation of ions and molecules required for metabolism. It has a high latent heat of vaporization which helps in the regulation of body temperature
Chemical properties of water: Amphoteric nature:
Water can act as both acid and base, which means that it is amphoteric in nature.
Example:
Acidic Behaviour: H2O(l)+NH3(aq) ⇌ H3O+(aq)+NH+4(aq)
Basic Behavior: H2O(l)+H2S(aq) ⇌ H3O+(aq)+HS−(aq)
Redox reactions:
Electropositive elements reduce water to hydrogen molecule. Thus water is a great source of hydrogen. Let us see an example in this case:
2H2O(l)+2Na(s)→2NaOH(aq)+H2(g)
During the process of photosynthesis, water is oxidized to O2. As water can be oxidized and reduced, it is very useful in redox reactions.
Hydrolysis reaction
Water has a very strong hydrating tendency due to its dielectric constant. It dissolves many ionic compounds. Some covalent and ionic compounds can be hydrolyzed in water.
Explanation:
Answer:
<h2> After one round: one strand of DNA will contain radioactive 3232P, while the other strand will not contain any radioactive phosphate.
</h2><h2> After two rounds: here 50% of DNA will have 3232P in both strands, while 50% will contain 3232P in one strand and nonradioactive in the other strand.
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Explanation:
1. In the initial sample which is immediately removed after addition of radioactive isotope of phosphorus ( 3232P), hence there is no incorporation of 3232P into the DNA because replication in the medium containing 3232P has not yet occurred.
2. After one round of replication in radioactive isotope of phosphorus ( 3232P) containing medium, here only one newly synthesized strand of DNA molecule will contain 3232P, while the other strand will not contain any radioactive isotope of phosphorus ( 3232P), because DNA replication occurs in semi-conservative way.
3. After two rounds of replication in medium which contains radioactive isotope of phosphorus ( 3232P), here 50% of the DNA molecules will have radioactive isotope 3232P in both strands, while the rest 50% will contain 3232P in only one strand and nonradioactive phosphorous in the other strand.
