Question

Prokaryotic cells are generally than the eukaryotic cells. (a) smaller, slower (b) Iarger, slower (c) smaller, faster (d) larger, faster

Short answer

Prokaryotic cells are smaller and have a faster metabolism and reproduction rate than eukaryotic cells, so the answer is (c) smaller, faster.

Step-by-step solution

Understanding Cell Types

Firstly, understand that prokaryotic cells are generally simpler organisms compared to eukaryotic cells. Prokaryotic cells, like bacteria, lack a nucleus and membrane-bound organelles, which are present in eukaryotic cells.

Comparing Sizes

Comparing the sizes of prokaryotic cells to eukaryotic cells is the next step. Prokaryotic cells are significantly smaller than eukaryotic cells. The size of a prokaryotic cell is typically 0.2-2.0 micrometers in diameter, whereas eukaryotic cells are generally 10-30 micrometers in diameter.

Assessing Relative Speeds

When referring to the 'speed' in the context of cellular operations, it's about metabolic rates or reproduction rates. Prokaryotic cells, due to their simpler structure and less complex regulatory systems, tend to reproduce and carry out metabolic processes at a faster rate than eukaryotic cells.

Choosing the Correct Answer

Based on the information about size and speed, the correct statement is that prokaryotic cells are smaller than eukaryotic cells and generally have a faster metabolism and reproduction rate. Therefore, the correct option is (c) smaller, faster.

Key concepts

Cell Size Comparison

When exploring the microscopic world, students often encounter two fundamental categories of cells: prokaryotic and eukaryotic. A remarkable difference between them is their size. Prokaryotic cells, such as bacteria, are much smaller, typically ranging from 0.2 to 2.0 micrometers in diameter. Eukaryotic cells, which include plant and animal cells, are considerably larger, usually spanning between 10 to 30 micrometers.

Why does this size difference matter? It influences not only how these cells interact with their environment but also how they grow and divide. The diminutive size of prokaryotic cells allows for a larger surface-area-to-volume ratio, which facilitates a more efficient exchange of nutrients and waste materials with the surroundings. In contrast, the larger eukaryotic cell contains an array of complex organelles, such as the nucleus, mitochondria, and chloroplasts (in plants), which are necessary for their more intricate functions.

Cellular Metabolism Rate

Cellular metabolism entails all the biochemical reactions that occur within a cell, sustaining life. Here, between prokaryotic and eukaryotic cells, the difference is not just in complexity, but in the pace of these metabolic activities too. Prokaryotic cells have a higher metabolic rate compared to their eukaryotic counterparts. This is because the smaller size of prokaryotic cells translates to quicker absorption of nutrients and rapid elimination of waste, streamlining their energy production.

Furthermore, without the need for compartmentalization in prokaryotes, as opposed to the organelles in eukaryotes, metabolic reactions can proceed without the delays of transport between different cell compartments. This swifter cycle of metabolism supports prokaryotic cells' ability to thrive in various environments, rapidly adapting to available resources or changes in their surroundings.

Cellular Reproduction Rate

One of the most profound distinctions between prokaryotic and eukaryotic cells lies in their reproduction rate. Prokaryotic cells reproduce at a faster rate through a simple process called binary fission. This is a single-step replication process where a prokaryotic cell divides into two identical offspring cells. Since there are fewer complications, such as no need for mitosis or cytokinesis as seen in eukaryotes, prokaryotic cells can rapidly multiply, sometimes in a matter of minutes under optimal conditions.

Eukaryotic cells, on the other hand, divide through a more complex process involving either mitosis or meiosis, followed by cytokinesis. They replicate their more extensive and complex genome and ensure proper segregation into daughter cells, significantly lengthening the reproduction cycle. Consequently, eukaryotic populations grow at a slower pace compared to prokaryotic ones, which can double their numbers at astonishing speeds.