General Biology 1 – Cell Theory and Cell Fundamentals

These question-and-answer flashcards cover essential points from the lecture: cell size and surface-area-to-volume ratio, general cellular functions, major contributors to cell theory, the three core principles of cell theory, homeostasis examples, and key distinctions from spontaneous generation.

Why are cells generally very small?

Because a smaller size provides a higher surface-area-to-volume ratio, allowing efficient nutrient uptake and waste removal.

What is the basic structural and functional unit of all living organisms?

The cell.

Which principle of cell theory explains why sterilization prevents infection?

Principle 3 – Cells come only from pre-existing cells; killing existing microbes prevents new ones from arising spontaneously.

What is homeostasis in the context of cellular function?

An organism’s ability to maintain a stable internal environment despite external changes.

Give two examples of cellular responses that help maintain homeostasis in humans.

Perspiration to remove excess heat and shivering to generate metabolic heat.

Which scientist first observed cork cells under a microscope and coined the term “cell”?

Robert Hooke.

Who disproved the theory of spontaneous generation with meat-jar experiments?

Francesco Redi.

Which scientist discovered microorganisms using handcrafted microscopes?

Anton van Leeuwenhoek.

Who proposed that all plants are composed of cells?

Matthias Schleiden.

Who proposed that all animals are composed of cells?

Theodor Schwann.

Which scientist stated that all cells arise from pre-existing cells?

Rudolf Virchow.

State Principle 1 of the cell theory.

Every living organism consists of one or more cells.

State Principle 2 of the cell theory.

The cell is the fundamental (smallest structural and functional) unit of life.

State Principle 3 of the cell theory.

All cells come from pre-existing cells and pass hereditary material to daughter cells during division.

List the four general functions of cells mentioned in the lesson.

Regulation of internal environment, acquisition and utilization of energy, responsiveness to the environment, and protection/support.

What form of energy is stored in food molecules and converted by cells for use?

Chemical energy.

Name one type of cell that requires large amounts of energy and its function.

Heart muscle cells – they use energy to pump blood.

How does skin tanning illustrate cellular responsiveness?

Skin cells release more pigment to protect underlying DNA from UV radiation after exposure.

What invention by Zacharias Janssen was crucial for the discovery of cells?

The first primitive compound microscope.

What does a high surface-area-to-volume ratio enable in cells?

Efficient exchange of gases, nutrients, and wastes with the environment.

Unicellular vs. multicellular organisms – what distinguishes them?

Unicellular organisms consist of a single cell performing all life functions; multicellular organisms have many specialized cells working together.

Which cell theory principle is illustrated when a pimple forms again after being pricked?

Principle 3 – New skin cells arise from pre-existing cells, leading to regeneration.

Provide one similarity between spontaneous generation theory and cell theory discussed in class.

Both attempt to explain the origin of living cells or organisms (though spontaneous generation is incorrect).

Provide one difference between spontaneous generation and cell theory.

Spontaneous generation claims life arises from nonliving matter, while cell theory states that new cells come only from existing cells.

Why is the cell’s surface area important for its survival?

It determines how quickly materials can enter or leave the cell, affecting metabolism and homeostasis.

Biology

The natural science discipline that studies living this.

Microbiology

The study of bacteria, viruses, parasites, fungus.

Taxonomy

study of structures and functions of cells