Question

What are the variations? How do they help organisms?

Answer 1

Hint: The Mutation is another phenomenon that leads to variation in DNA. The Variation is a phenomenon that results in changes in the genotype and the phenotype of an organism. One end to another end continuously runs in the DNA helix. Therefore loss or gain of a segment of DNA results in an alteration in chromosomes.

Complete answer:
In 1902, Walter S. Sutton and T. Boveri proposed the chromosomal theory of heredity. The theory provides a way to explain how the cellular transmission of chromosomes passes Genetic determinant offspring.

According to this view:
- Passed along generation after generation from parent to offspring and chromosomes are duplicated.
- The nuclei of almost eukaryotic cells contain chromosomes that are found in homologous pairs. One member of each pair is inherited from the mother, the other pair is inherited from the father. At meiosis, one of the two members of each pair segregates into one daughter nucleus and the other segregates into different daughter nucleus. Therefore, gametes contain one set of chromosomes.
- When gamete formation takes place, different types of chromosomes segregate independently of each other.
- Each parent chromosome contributes one set of chromosomes to its offspring.

Note: Gene Variations occur in two different ways:
They can be inherited from a parent or acquired during a person’s lifetime. Variations that are passed to offsprings are called heredity Variations. This type of Variation is present throughout a person’s life in virtually every cell in the body. Variations that occur in the DNA of a cell at some time during life are termed acquired Variations. Ultraviolet radiation or changes in environmental factors affected by a DNA copies itself during cell division.