Which component is present in some viruses but absent in others?
a.)nucleic acid
b.)capsid
c.)envelope
d.)cell membrane

Ans. Option C). envelope.

Viruses are small infectious particles that represent connecting link between non-living and living things. They are made up of nucleic acid (either RNA or DNA) and a protective coat or capsid, which is composed of protein molecules. Viruses lack cell membranes.

In some virus, an another layer is also present outside the capsid, known as envelope. These viruses are known as enveloped viruses. On the other hand, some viruses lack envelopes and are known as naked viruses.

Thus, the correct answer is option C). 'envelope.'

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.