General Biology 1 – Cell Theory, Structure, and Diversity

A comprehensive set of Question-and-Answer flashcards covering the history of cell theory, major contributors, cell structures and organelles, cellular processes, differences between prokaryotic/eukaryotic and plant/animal cells, bacterial anatomy, and specialized cell types in the human body.

What is the primary building block of life?

The cell.

Which organism has the smallest known cell and how large is it?

Mycoplasma gallisepticum; about 0.3 µm (nanometres in notes).

Which cell is considered the largest and what is its size?

An ostrich egg; up to 6 inches in diameter.

Who produced the first compound lenses that led to microscopes?

Hans Lippershey and Zacharias Janssen (1590s).

Who coined the term “cell” and in what material did he observe them?

Robert Hooke; in cork (1665).

Which scientist is called the Father of Ancient Microbiology?

Antonie van Leeuwenhoek (1674).

What name did Leeuwenhoek give to the microscopic organisms he observed?

“Animalcules.”

What was Matthias Schleiden’s major contribution to cell theory?

Stated that all plants are made of cells (1838).

What did Theodor Schwann add to cell theory?

Declared that all animals are made of cells (1839).

Who stated “omnis cellula e cellula,” and what does it mean?

Rudolf Virchow (1855); it means all cells arise from pre-existing cells.

Which experiment refuted spontaneous generation using meat and maggots?

Francesco Redi’s experiment.

State the three tenets of the modern Unified Cell Theory.

1) The cell is the basic unit of life; 2) All living things are composed of one or more cells; 3) New cells arise from existing cells.

Name any four life processes of a cell.

Examples: Nutrition, Digestion, Absorption, Biosynthesis, Excretion, Egestion, Secretion, Movement, Irritability, Respiration, Reproduction.

What are the three basic parts of a typical cell?

Cell membrane, cytoplasm, nucleus.

Which cell structure acts as the ‘gate’ controlling movement in and out?

The cell membrane (plasma membrane).

What additional outer layer provides plants with support and protection?

The cell wall.

What goo-like substance fills the interior of a cell?

Cytoplasm.

Which organelle houses DNA and directs cellular activities?

The nucleus.

What is the function of the nucleolus?

Contains RNA and assembles ribosomes/proteins.

Which organelles carry out protein synthesis?

Ribosomes (free or attached).

What is the main storage organelle for water in plant cells?

The large central vacuole.

Which organelle is known as the “powerhouse of the cell,” and why?

Mitochondrion; it produces ATP through respiration.

Which organelle packages and ships proteins?

Golgi apparatus (Golgi bodies).

What major roles does the endoplasmic reticulum (ER) serve?

Production, processing, and transport of proteins and lipids (smooth & rough ER).

Which organelle contains digestive enzymes for breaking down macromolecules and is nicknamed the ‘suicide bag’?

Lysosome.

What is the main role of peroxisomes?

Break down materials using oxidative enzymes (digestive vesicles).

Which filament network maintains cell shape and enables movement of organelles?

The cytoskeleton.

Where does photosynthesis occur in plant cells?

Chloroplasts containing chlorophyll.

What structure helps organize microtubules during animal cell division?

The centrosome (pair of centrioles).

Give two key differences between prokaryotic and eukaryotic cells.

Prokaryotes lack a nucleus and have few organelles; eukaryotes have a nucleus and many complex organelles.

Name three domains or examples of prokaryotes.

Bacteria, Archaea, Cyanobacteria.

List the three basic bacterial shapes.

Cocci (spheres), Bacilli (rods), Spirilla (spirals).

What is the fundamental unit of measurement in bacteriology?

The micron (micrometer, µm).

What protein forms bacterial flagella and what is their function?

Flagellin; provides motility.

State one function of the bacterial capsule.

Attachment, protection from phagocytosis, nutrient reserve, or desiccation resistance.

Describe the composition and role of the bacterial plasma membrane.

Phospholipid bilayer (hydrophilic phosphate heads, hydrophobic fatty acid tails); selectively permeable barrier.

Where is bacterial DNA located?

In the cytoplasm as a circular chromosome (not membrane-bound).

What polymer composes the bacterial cell wall and what staining differentiates its types?

Peptidoglycan; Gram staining (Gram+ purple, Gram– pink/red).

List any three similarities between plant and animal cells.

Both have cell membrane, cytoplasm, nucleus, ribosomes, mitochondria, vacuoles, ER, Golgi, etc.

Name two organelles present in plant cells but absent in animal cells.

Cell wall and chloroplasts.

Which digestive organelle is abundant in animal cells but rare in mature plant cells?

Lysosomes.

What are stem cells and what is their key ability?

Unspecialized cells capable of prolonged self-renewal and differentiation.

What is hematopoiesis?

The production of blood cells.

Which blood cells lack a nucleus and carry oxygen?

Red blood cells (erythrocytes).

Which white blood cell type produces antibodies?

Lymphocytes.

Which blood component is responsible for clotting and tissue repair?

Platelets (thrombocytes).

Which leukocyte primarily destroys bacteria and fungi?

Neutrophils.

Which immune cell type cleans up damaged cells?

Monocytes/macrophages.

Which leukocytes combat parasites and participate in allergic responses?

Eosinophils and basophils (basophils chiefly allergic response).

What is the main function of adipocytes?

Store fat as an energy reserve and help insulate the body.

Name the four principal skin cell types.

Keratinocytes, melanocytes, Merkel cells, Langerhans cells.

What is the role of endothelial cells?

Form the thin inner lining of blood vessels.

What is the primary function of neurons?

Transmit electrical signals to coordinate body functions.

What are gametes?

Reproductive cells (sperm and egg) used in sexual reproduction.