How do Organisms Reproduce?
Reproduction and its importance
Do all living organisms reproduce? Why do offspring’s resemble their parents? Does reproduction always involve the participation of two parents?
Reproduction is a characteristic feature of all living organisms. It involves the creation of organelles, cells, or organisms of the same kind.
Reproduction is necessary for the survival of a particular species. During reproduction, the information for inheritance of characteristics is passed on from the parents to the offsprings in the form of DNA.
DNA (Deoxyribonucleic acid) is a genetic material found in the chromosomes, which are present in the nucleus of a cell. It is a chemical, which carries genetic information required by the cells to divide and produce proteins.
DNA is made up of genes. A set of genes are responsible for the production of a specific protein. Each protein is specific for its specific function. Therefore, it is the DNA that decides the formation of the structural, enzymatic, hormonal, and other components in an organism. Genes are responsible for the physical appearance and body functions of an organism.
Therefore, it is the DNA that gets transferred from the parents to the offsprings and makes them look similar to their parents.
Transfer of DNA
The reproducing cells produce a copy of DNA through some chemical reactions. This, in turn results in the formation of two copies of DNA. Now, these copies need to be separated from each other. The newly-formed copy of DNA cannot be simply pushed out, as it lacks an organized cellular structure. Hence, the copying of DNA always takes place with the creation of an additional cellular structure. This process is then followed by the division of a single cell to form two cells.
Do you know that larvae of the Axolotls Mexican salamander are capable of reproducing at 12 months of age?
DNA carries genetic material and passes it from the parents to the offsprings. But are we similar to our parents in all aspects?
Case I: An organism reproduces an offspring, which is similar to its parents in all aspects, with no changes occurring in subsequent generations.
In this situation, the offspring is adapted like its parent. It has all the characteristic features present in the parent and is well suited for that environment.
Case II: An organism reproduces an offspring similar to its parent, but a variation (like the offspring can withstand temperature changes i.e. it can survive in very high and low temperatures) has occurred, and this variation is passed to the subsequent generations.
In this situation, the offspring is similar to the parent, but is more adapted than the parent due to the variation. Therefore, it has better chances of survival than the parent.
Results of analysis: In nature, variations occur during sexual reproduction. If this variation is beneficial to the species, it is selected and remains in the population. This is because the variant species are more adapted. Therefore, they can survive better and reproduce to pass the genes to the offsprings.
Therefore, we can say that variations are important.
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