which series is arranged in the correct order according to decreasing size structures?
1. DNA, nucleus, chromosome, nucleotide, nitrogen base
2. nucleotide, chromosome, nitrogen base, nucleus, DNA
3. nucleus, chromosome, DNA, nucleotide, nitrogen base
4. chromosome, nucleus, nitrogen base, nucleotide, DNA
Out of the options presented above, #3 is correct.
In a cell, the nucleus is the structure which contains the chromosomes in the cell. Therefore, the nucleus must be larger than the chromosomes themselves.
What is a chromosome? As chromosome is a "packaged" structure, made up of DNA and proteins, that contains the genetic information in the cell. If the chromosome is made up of multiple strands of DNA, it is therefore larger than the DNA itself.
Like mentioned before, DNA is the molecule in the cell that holds the biological genetic coding. It consists of a series of nucleotides which are paired together to form the A-T & C-G base pairs. Since the DNA is made up of many nucleotide sub-units, the DNA is obviously bigger than its sub-units.
Therefore, the next one is the nucleotide. The nucleotide is a sub-unit of the DNA; two different nucleotides (there being A, T, C, & G) form a nucleotide pair, as mentioned above. Each nucleotide contains a nitrogen base of either adenine, guanine, thymine, or cytosine. Therefore, the nucleotides are larger than the nitrogen bases inside them.
Lastly, therefore, is the nitrogen base. It is the base chemical of each nucleotide, consisting of the chemicals adenine, guanine, thymine, or cytosine.
Therefore, the correct sequence is #3:
Nucleus -> Chromosome -> DNA -> Nucleotide -> Nitrogen Base
The series arranged in order according to decreasing size structures is: nucleus, chromosome, DNA, nucleotide, nitrogen base. So item three (3) is the answer.
Answer explained in detail:
In a multi-cellular organisms, the organelle known as the nucleus houses the chromosomes of the cell. Chromosome numbers vary among organisms, for example, humans have 46 chromosomes.
Chromosomes are formed by a long chain of DNA.
DNA is short for deoxyribonucleic acid. It is a pentose sugar formed from organic bases joined by hydrogen bonds which store the genetic information for the lifetime of an organism.
Nucleotides are the subunits of DNA.
Simply, the nucleus encloses the structures of chromosomes. So the nucleus has to be bigger than chromosomes in order to do that. The chromosome is formed by long joined strands of DNA, so it takes several DNA strands to form a chromosome. Therefore, the chromosome is bigger than DNA. DNA have subunits which are nucleotides. So DNA is obviously larger than their nucleotides subunits.
More information about DNA is available at the attached link.