Question

Fill in the Blank. The cells of prokaryotic organisms lack a _______.

Short answer

nucleus

Step-by-step solution

Understand the Term 'Prokaryotic Organisms'

Prokaryotic organisms are unicellular organisms that do not have a distinct nucleus or specialized organelles. They include bacteria and archaea.

Identify Key Differences

The key difference between prokaryotic and eukaryotic cells is that prokaryotic cells lack membrane-bound organelles such as the nucleus.

Fill in the Blank

Based on the understanding that prokaryotic cells do not have a distinct nucleus, the blank can be filled with the word 'nucleus'.

Key concepts

prokaryotic vs. eukaryotic cells

To understand the difference between prokaryotic and eukaryotic cells, it's essential to look at their structures and organization. Prokaryotic cells are the simplest form of cells and do not have a nucleus or other membrane-bound organelles. They include bacteria and archaea.

On the other hand, eukaryotic cells are generally more complex. These cells have a defined nucleus that encloses their genetic material. They also contain various membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus.

• Prokaryotic cells: Simple, no nucleus, no membrane-bound organelles.
• Eukaryotic cells: Complex, have a nucleus, have membrane-bound organelles.

Knowing these differences can help us understand their functions and roles in various organisms.

unicellular organisms

Unicellular organisms consist of a single cell that performs all the functions necessary for life. Prokaryotic organisms, like bacteria and archaea, are typically unicellular. In these organisms, a single cell carries out all the life processes such as growth, reproduction, and metabolism.

Although they are just one cell, these organisms can thrive in various environments—ranging from extreme heat to extreme cold, and even in highly acidic or basic environments.

• Unicellular: Made of one cell.
• Prokaryotes: Often unicellular like bacteria.

membrane-bound organelles

Membrane-bound organelles are specialized structures within a cell that are enclosed by lipid membranes. These organelles carry out specific functions critical for cell survival and proper operation. Eukaryotic cells have various membrane-bound organelles, including the nucleus, mitochondria, and lysosomes.

The absence of these organelles in prokaryotic cells leads them to rely on other cell mechanisms to perform necessary functions.

• Membrane-bound organelles: Only in eukaryotic cells.
• Examples: Nucleus, Mitochondria.
• No membrane-bound organelles: Prokaryotic cells.