Cell Biology Basics Quiz

The smallest unit capable of carrying out all life processes.

Robert Hooke, in 1665, observed dead cells in cork slices using a microscope.

Anton van Leeuwenhoek, in 1673, observed living cells in microorganisms. Leeuwenhoek called these organisms 'animalcules,' which we now call protists.

The cell theory states that:

1. All living organisms are composed of one or more cells.
2. Cells are the basic units of structure and function in living organisms.
3. All cells arise from pre-existing cells.

The cell theory revolutionized our understanding of life by establishing the cell as the fundamental unit of all living organisms, explaining the continuity of life through cell division.

Cells have specific shapes that reflect their functions.

The surface area-to-volume ratio limits cell size. As a cell grows, its volume increases faster than its surface area.

A cell consists of three basic parts:

1. Plasma membrane: Outer boundary that regulates what enters and leaves the cell.
2. Cytoplasm: Fluid inside the cell where organelles are suspended.
3. DNA: Genetic material that directs cell activities.

The fluid portion of the cytoplasm, excluding membrane-bound organelles, and containing molecules and small particles like ribosomes.

The nucleus is a membrane-bound organelle that contains a cell's DNA, directing cellular activities and storing genetic information.

Cell membranes consist of a phospholipid bilayer, a double layer of phospholipids with hydrophilic heads and hydrophobic tails.

Cholesterol, a type of lipid, is embedded within the cell membrane and helps maintain its firmness and prevents freezing at low temperatures.

Proteins embedded within the phospholipid bilayer, aiding in transporting large molecules or cell recognition.

The fluid mosaic model describes the cell membrane as a fluid, constantly changing mosaic of lipids and proteins.

The cytoskeleton is a network of protein fibers that provides structural support, helps maintain cell shape, and facilitates movement within the cell.

Mitochondria are membrane-bound organelles that generate energy (ATP) through cellular respiration, acting as the 'powerhouses' of the cell.

One cell organisms, like bacteria, are made up of one cell. Many cells organisms are made up of many cells that have specialized roles. This specialized division of labor is called differentiation.

Prokaryotes, like bacteria, lack a nucleus and membrane-bound organelles. They have a single circular chromosome located in a region called the nucleoid. They are surrounded by a cell membrane and a cell wall made of peptidoglycan.

Eukaryotic cells, like those found in animals, plants, fungi, and protists, have a nucleus and membrane-bound organelles. This allows for greater complexity and specialization within the cell.

The plasma membrane encases the cell, acting as a barrier that controls what enters and leaves. This is vital for maintaining the cell's internal environment and regulating its processes.

The cytoplasm contains the cell's internal fluid, cytoskeleton, and all the organelles except the nucleus. It is the site of many cellular processes, including protein synthesis and energy production.

The nucleus is the command center of the eukaryotic cell, containing the genetic material, DNA. The nucleus directs cellular activities, including protein synthesis and cell division.

The process whereby lysosomes break down worn-out organelles within a cell.

When a cell's own lysosomes digest its damaged or excess parts, causing the cell to break down.

The process of creating proteins using ribosomes, the rough endoplasmic reticulum (ER), and the Golgi apparatus.

A network of protein fibers that provides structural support, helps maintain a cell's shape, and facilitates movement.

Small, hair-like structures that extend from the cell's surface, assisting in movement.

Longer, whip-like structures extending from the cell surface, promoting movement.

Two short, cylindrical structures composed of microtubules, involved in cell division.

A rigid structure outside the cell membrane in plant cells, providing support and protection.

The threadlike form of DNA found in non-dividing cells.

The condensed, compact form of DNA that forms during cell division, allowing for accurate distribution of genetic material to daughter cells.

This double-layered membrane encloses the nucleus, protecting it and regulating the movement of substances in and out.

These powerhouses of the cell transform energy from organic compounds into a usable form of energy called ATP.

Small structures composed of RNA and protein, ribosomes are responsible for protein synthesis. They can be free in the cytoplasm or attached to the endoplasmic reticulum.

This extensive network of interconnected membranes serves as an intracellular highway, transporting materials throughout the cell. Its rough form is studded with ribosomes and involved in protein synthesis; its smooth form is involved in lipid synthesis and detoxification.

This organelle acts as a processing and packaging center for proteins, ensuring they are properly folded and directed to their correct destinations within the cell.