Basic Events in Reproduction
Reproduction is a biological process by which new individuals of the same species are produced by existing organisms. Reproduction is essential for the survival of a species on the earth. The process of reproduction ensures continuity of life on earth. Reproduction gives rise to more organisms with the same basic characteristics as their parents.
A basic event in reproduction is the creation of a DNA copy as the DNA in the cell nucleus is the information source for making proteins. If the information changes, different proteins will be made leading to altered body designs. Also, during cell division, an additional cellular apparatus is created so that the DNA copies separate, each with its own cellular apparatus.
Example 1.
What is the importance of DNA copying in reproduction?
Answer:
The creation of a DNA copy is a basic and important event in reproduction. DNA in the cell nucleus contains the blueprint of body design and information for the inheritance of characteristic features from parents to next generation. During Reproduction, as the cell divides, a copy of DNA along with additional cellular apparatus, is transferred from the parent cell to its offspring.
Variation
Cells use chemical reactions to build copies of their DNA but this process of copying the DNA will have some variations due to which the DNA copies will be similar but not identical to the original. If the variations are so drastic that the new DNA copy cannot work with the cellular apparatus it inherits, then the newborn cell dies.
This tendency for variation during reproduction is the basis for evolution.
The Importance of Variation
Genetic variation is when the genes carried by the members of a population differ from one another (like hair or eye color). Genetic variation is important. If there are sudden changes in the environment, the individuals of the population will vary enough that some will be able to adapt and survive.
- It helps the species of various organisms to survive and flourish even in adverse environments due to the presence of some variations in some individual organisms to tolerate extreme changes in environmental conditions.
- It provides stability to the population of various species by preventing them from getting wiped out during adverse conditions.
Example 2.
Why is variation beneficial to the species but not necessarily for the individual?
Answer:
If a population of reproducing organisms were suited to a particular niche and if the niche were drastically altered, the population could be wiped out However, if some variations were to be present in a few individuals in these populations, there would be some chance for them to survive. Thus, variation is beneficial to the species but not necessarily for the individual as it helps in the survival of the species.