Question

For which organism, the growth is synonymous with reproduction? (a) Unicellular algae (b) Amoeba (c) Bacteria (d) All of these

Short answer

The growth is synonymous with reproduction for all organisms listed, which includes unicellular algae, amoeba and bacteria. So, the correct answer is (d) all of these.

Step-by-step solution

Recalling the reproductive process of unicellular organisms

In unicellular organisms such as algae, amoeba, and bacteria, they reproduce mainly through a simple division process where a single cell divides to produce two new cells. This means, for them, growth is synonymous with reproduction.

Selecting the correct choice

Given that all mentioned organisms are unicellular and reproduce through simple division, the answer is that growth is synonymous with reproduction for all these organisms. It's important to remember that multicellular organisms have a separate process for growth and reproduction.

Key concepts

Cell Division

At the heart of unicellular organism reproduction is cell division, an essential process that enables a single cell to duplicate and produce two new cells. This fundamental process is not only pivotal for reproduction but also for growth and repair in multicellular organisms. In the case of unicellular organisms, cell division is directly equated to reproduction since the entire organism is just a single cell.

There are several types of cell division, but most unicellular organisms, including bacteria and unicellular algae, rely on binary fission. This is a simple form of division wherein the cell’s DNA is replicated, and the cell grows until it partitions into two daughter cells with identical genetic information. It’s a straightforward yet highly efficient method of reproduction that ensures survival and propagation of species in favorable conditions.

Unicellular Algae

Focusing on unicellular algae, these photosynthetic organisms are found in diverse environments from oceans to freshwaters and are capable of converting sunlight into energy through photosynthesis. Their simplicity as unicellular organisms means they have streamlined processes for sustaining life, including reproduction.

Unicellular algae primarily reproduce through binary fission, similar to bacteria. However, under certain circumstances, some algae can reproduce sexually or through other asexual methods like fragmentation or budding. These mechanisms provide genetic variability and adaptability to changing environments. Moreover, unicellular algae are important contributors to aquatic ecosystems, producing a significant amount of the world's oxygen while also serving as the foundation of many food webs.

Bacterial Reproduction

Bacterial reproduction is a marvel of simplicity and efficiency. These organisms, which can be found virtually everywhere on our planet, also reproduce through binary fission. The process begins when the bacterial cell duplicates its DNA and increases in size until a new cell wall forms, dividing the original cell into two new cells.

However, bacteria also have a unique method called conjugation. It involves the transfer of genetic material between bacterial cells through direct contact. This allows for genetic diversity among bacteria, which is crucial for survival in the presence of antibiotics or harsh environmental conditions. Therefore, even though bacteria are unicellular and replicate mainly through cell division, they do have mechanisms to share and recombine genetic material, which is a form of genetic reproduction adding to their evolutionary success.