Question

Which is the common organelles that are found in both eukaryotes and prokaryote? (a) Lysosome (b) Ribosome (c) Vacuole (d) Mitochondria

Short answer

The common organelle that can be found in both eukaryotic and prokaryotic cells is the ribosome.

Step-by-step solution

Understanding the question

The exercise is asking for the organelle that can be found in both eukaryotic cells and prokaryotic cells. Eukaryotic cells are complex and contain numerous cell organelles, while prokaryotic cells are simpler and have few organelles.

Review the organelles

Look at the response options and look into the characteristics of each organelle. (a) Lysosomes are found predominantly in animal cells and are used to digest macromolecules - they aren't found in prokaryotes. (b) Ribosomes are responsible for protein synthesis and are found in both eukaryotes and prokaryotes. (c) Vacuoles are storage organelles found predominantly in plant cells and do exist in some prokaryotic cells, but not all. (d) Mitochondria are involved in energy production and found only in eukaryotic cells.

Picking the right answer

The only organelle listed that is common to both eukaryotic and prokaryotic cells is the ribosome. So, the correct answer is (b) Ribosome.

Key concepts

Ribosome

Understanding the pivotal role of ribosomes is essential for students studying cell biology. These tiny structures are the factories of the cell where proteins are synthesized, a process known as translation. Each ribosome is essentially a complex molecular machine, found within all living cells, tasked with linking amino acids together in the order specified by messenger RNA (mRNA), which is a copy of the DNA sequence.

Ribosomes are made up of two main components: the small and large subunits, both consisting of ribosomal RNA (rRNA) and proteins. In eukaryotic cells, ribosomes can be found floating freely in the cytoplasm or attached to the rough endoplasmic reticulum, allowing them to synthesize proteins that will be either kept within the cell or secreted out of it. In contrast, prokaryotic cells, which lack a nucleus and other membrane-bound organelles, have ribosomes that are slightly smaller but serve a similar fundamental purpose.

• Ribosomes are crucial in both eukaryotic and prokaryotic cells for protein synthesis.
• Their universal presence illustrates the evolutionary importance of protein synthesis across all forms of life.
• They may vary slightly between prokaryotes and eukaryotes but perform the same essential function.

Eukaryotic Cells

Eukaryotic cells are one of the two primary types of cells that make up all known life forms; the other being prokaryotic cells. The defining characteristic of eukaryotic cells is the presence of a true nucleus, encased within a nuclear envelope, which houses the cell's genetic material.

Other distinguishing features include the presence of membrane-bound organelles such as mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and more. These specialized structures compartmentalize cellular processes, allowing efficient metabolism, regulated gene expression, and localization of reactions.

Eukaryotic cells are typically much larger than their prokaryotic counterparts and are found in organisms that are classified as fungi, plants, and animals. They possess a complex structure and organization that allows them to undertake a vast array of functions necessary for sustaining more complex life forms.

Prokaryotic Cells

Prokaryotic cells are simpler and more ancient than eukaryotic cells. They are characterized by the absence of a true nucleus and membrane-bound organelles. This doesn't mean they are primitive or less sophisticated; prokaryotes are immensely successful and can be found in virtually every environment on Earth.

What defines these cells are features such as a single, circular chromosome located in a region called the nucleoid, the use of binary fission as a means of reproduction, and the presence of a rigid cell wall in many species, which offers structural support and protection. Bacteria and Archaea are the two domains that consist of prokaryotic life-forms.

• Prokaryotic cells are smaller and simpler in structure compared to eukaryotic cells.
• Despite their simplicity, they are highly adaptable and can live in extreme conditions.
• Their successful adaptations to various environments make them crucial to our ecosystem and to the study of life's evolution.