Problem 117 - Objective Biology for NEET

Question

Assertion: Growth and reproduction is synonymous in amoeba. Reason: Amoeba is unicellular organism.

Step-by-Step Solution

Answer

The assertion 'Growth and reproduction is synonymous in amoeba' is correct, as is the reason 'Amoeba is a unicellular organism'. In unicellular organisms, the processes of growth and reproduction are synchronous, which is achieved through the process of binary fission.

Step 1: Review Biological Principles

In unicellular organisms like an amoeba, growth and reproduction are actually synonymous. This is because reproduction in these organisms is carried out by a process known as binary fission, where the parent cell divides into two daughter cells. In this process, an amoeba grows in size until it has enough cellular material to divide into two cells, hence growth and reproduction are considered as a single synchronized process.

Step 2: Analysis of the Assertion and Reason

Given the above, we can conclude that the assertion is true. The process of growth and reproduction are synonymous in an amoeba. The provided reason is also correct because being a unicellular organism, an amoeba replicates itself through binary fission, a process in which growth and reproduction are one and the same.

Key Concepts

Binary Fission

Binary fission is a fundamental process of asexual reproduction in unicellular organisms, including bacteria, archaea, and protozoa such as amoebae.
During binary fission, an organism duplicates its genetic material and then divides into two parts, with each new organism receiving one copy of DNA, ensuring they are genetically identical. This process is relatively simple and quick, making it an efficient way to reproduce.

The Process of Binary Fission

• The organism's DNA replicates.
• The cell elongates, and the DNA is distributed to opposite ends of the cell.
• A division septum forms in the middle, gradually deepening until it partitions the cell into two halves.
• Finally, the cell splits into two daughter cells, each with a complete set of genetic information.

Binary fission allows for the rapid expansion of populations and occurs in favorable conditions to maximize the spread of the species.

Unicellular Organisms

Unicellular organisms are life forms composed of a single cell that performs all the necessary functions to sustain life.
These organisms range from bacteria to single-celled algae and protozoa, like amoebae. In these organisms, one cell carries out digestion, respiration, reproduction, and all other life-sustaining processes.

Features of Unicellular Organisms

• All life processes occur within one cell.
• They can inhabit diverse environments, from deep oceans to hot springs.
• They often reproduce quickly through processes like binary fission.
• Genetic mutations have immediate effects due to the single-cell nature, leading to rapid evolution.

The existence of unicellular organisms ensures ecological diversity and fills various niches in ecosystems. Their adaptability and rapid reproduction rates make them vital to life on Earth.

Biological Principles

Biological principles are foundational truths that govern the behavior of living organisms.
These principles help us understand phenomena ranging from cellular processes to ecosystem dynamics. One of these principles is the notion that in unicellular organisms, growth, and reproduction are often synonymous because the same process that leads to an increase in cell size (growth) also results in the formation of new individuals (reproduction).

Key Biological Principles

• The cell theory states that all living things are composed of cells and that cells arise only from pre-existing cells.
• Homeostasis refers to the maintenance of a constant internal environment.
• Genetics principles dictate how traits are inherited from one generation to the next.
• The principle of evolution by natural selection explains the diversity of living organisms.

Understanding these principles provides a framework for grasping more complex biological concepts and appreciating the intricacies of life at all levels.