Problem 38 - Objective Biology for NEET

Question

Which of the following is true about appendix? (a) Narrow finger-like tubular projection (b) Arises from the caecum (c) Vestigial organ (d) All of these

Step-by-Step Solution

Answer

The correct answer is (d) All of these. Each statement accurately describes the appendix, a part of the human body.

Step 1: Analyze answer option a

The first option states that the appendix is a 'Narrow finger-like tubular projection'. If you refer to an anatomy book or any other reliable source about the human body, you will confirm that the appendix indeed is a narrow tube that is shaped a bit like a finger. So, this option is correct.

Step 2: Analyze answer option b

The second option suggests that the appendix 'Arises from the caecum'. Referring again to the anatomy source, it will confirm that the appendix is connected to the caecum, a part of the large intestine. The appendix indeed originates from the caecum. Therefore, this option is also correct.

Step 3: Analyze answer option c

The third option is that appendix is a 'Vestigial organ'. A vestigial organ is an organ that has lost all or most of its original function through evolution. The human appendix is generally considered to be a vestigial organ, since it doesn't appear to have a crucial function in the body, unlike other organs. Therefore, this option is also correct.

Step 4: Make a Decision

After examining each option, it becomes clear that all presented statements about the appendix are correct, they all accurately describe the appendix, hence answer option (d) 'All of these' would be the right answer.

Key Concepts

Vestigial Organs

What exactly are vestigial organs? These are structures in our bodies that have lost most or all of their original function through the long process of evolutionary change. A common example is the human appendix.

Originally, it is believed that our distant ancestors used the appendix for digesting cellulose when their diet was predominantly herbivorous. As humans evolved and their diets shifted, their digestive systems also adapted. The once-important appendix lost its critical function of helping to digest tough plant materials.

However, recent studies suggest that the appendix may have a role in maintaining gut flora, acting as a safe house for friendly bacteria. But this function is not considered crucial for survival, which is why the appendix still fits the category of a vestigial organ. While some vestigial organs have become entirely useless, others have developed a secondary function over time.

Anatomy of the Appendix

Delving into the anatomy of the appendix, it's a narrow finger-like pouch protruding from the cecum, the beginning of the large intestine. Its size can vary, but on average, it's about four inches long and located in the lower right abdomen.

The appendix is made of similar tissues as the rest of the colon, but has a higher concentration of lymphatic tissue. Earlier interpretations of the appendix's role in the digestive process have been largely dismissed, although there is still ongoing research on possible immune functions it might serve.

If the appendix becomes inflamed or infected, a condition known as appendicitis occurs, which can be life-threatening if not treated. The common procedure for appendicitis is an appendectomy, the surgical removal of the appendix, which has been performed safely for over a century.

Biological Evolution

Biological evolution explains the process of change in the inherited characteristics of biological populations over successive generations. Evolutionary processes give rise to diversity at every level of biological organization, including species, individual organisms, and at the level of molecular genetics.

Evolution occurs due to variations in genetic material and can lead to the development of new species. These genetic variations can arise spontaneously through mutations or can be the result of external factors such as environmental pressures and the influence of other species.

Over time, these variations can either confer an advantage or disadvantage to an individual's survival and reproduction, thus influencing the frequency of traits through the mechanism of natural selection. It is the reason some organs, like the appendix, may lose their primary functions because they are no longer necessary or advantageous in the current environment.