Difference Between Chromosome and Gene

Difference between Chromosome and Gene: Chromosomes and genes are forms of the genetic component of a eukaryotic cell. A chromosome is a thread-like structure that is found in the nucleus of a cell. It consists of DNA and proteins. The DNA contains many functional and non-functional units called the gene. Both genes and chromosomes have only one function i.e. to hold and pass the genetic information. So, genes and chromosomes are alternate forms of the DNA only.

Difference Between Gene and Chromosome

Characteristics	Gene	Chromosome
Definition	Segments of DNA or RNA that codes for certain characters.	DNA and proteins are packed together to form the chromosome.
Composition	A single gene forms the locus of a chromosome.	A single chromosome consists of many genes.
Visibility under the microscope	Genes are not visible under a microscope.	Chromosomes are visible under the microscope.
Occurrence	Occurs in pairs.	Occurs in pairs.
Mutation	The amount of mutation is small.	The amount of mutation is large.
Type of mutation	Mutation can be point mutation or frameshift mutation that can be either by insertion or deletion.	The mutation causes abnormalities like deletion, rearrangement, inversion, and duplication.

Gene

Gene in simple terms can be called the basic physical and functional unit of heredity. They may or may not code for the functional proteins that make up the living system in one form or another. Human genes have nucleotide bases that range from a few hundred to millions per gene and the whole human genome almost comprises around twenty to twenty-five thousand genes. Genes are found in pairs i.e. two copies of a gene and in sexually reproducing organisms these two copies are inherited from each parent, however, there is a certain variation in the coding of some genes that makes offspring different from parents.

Chromosomes

Chromosome in simpler terms can be called the thread-like structure that consists of DNA, and proteins. It helps in the packing of the DNA inside the nucleus of a cell and during division pass on that genetic information into the new cell. In humans there are 23 pairs of chromosomes are found of which 22 pairs are the autosomes that code for different somatic characters of the body and 1 pair codes for the sexuality of the body. As with the gene (actually, it is the gene but in a combined form of many genes), it is also found in pairs one of which comes from each parent.

FAQs on Genes and Chromosomes

Q1: Who discovered DNA as an acidic substance?

Answer:

Friedrich Meischer in 1869 discovered DNA as an acidic substance.

Q2: What are the four bases that form the nucleotides?

Answer:

Nucleotides are formed by nitrogenous bases adenine, thymine(in DNA only), cytosine, guanine, and uracil (in RNA only).

Q3: Which gene in humans has the largest number of base pairs?

Answer:

The human dystrophin gene is the largest gene containing around 2,300 kilobases.

Q4: How many chromosomes do normal human cells have?

Answer:

A normal human cell has 23 pairs i.e. 46 chromosomes.

Q5: Which is the largest human chromosome?

Answer:

The largest human chromosome is chromosome number 1 which contains around 250 million base pairs.