Cell Theory, Cell Organelles, and Cell Types - Study Flashcards

Flashcards cover the basics of cell theory history, organelles and their functions, prokaryotic vs. eukaryotic cells, specialized cell modifications, and examples of prokaryotic and eukaryotic organisms and plant/animal kingdoms as described in the notes.

What term did Robert Hooke coin in 1665 and what did his observation of cork reveal about cells?

He coined the term 'cell' and observed cork’s compartments, laying the foundation for modern cell biology.

Who was the first to observe living cells and what term did he use for microscopic life forms?

Anton van Leeuwenhoek; observed living cells (blood and sperm) and called them 'animalcules' in 1676.

What was Matthias Schleiden's key contribution to cell theory?

Plants are composed of cells; helped establish that all plants are cellular (1838).

What crucial idea did Theodor Schwann contribute to cell theory?

Extended cell theory to animals; identified animal cells and the unity of cellular structure (1839).

What is Rudolf Virchow's essential postulate?

All cells arise from pre-existing cells through cell division; rejected spontaneous generation (1858).

What is Postulate 1 of the Cell Theory?

All living organisms are composed of one or more cells.

What is Postulate 2 of the Cell Theory?

The cell is the basic unit of structure, function, and organization in all living things.

What is Postulate 3 of the Cell Theory?

All cells come from pre-existing cells through cell division.

What is the primary function of the cell membrane?

Acts as a selectively permeable barrier that controls substance entry/exit; maintains internal balance; phospholipid bilayer with embedded proteins.

What is cytoplasm and its role in the cell?

Jelly-like fluid inside the cell that surrounds organelles; enables movement of materials and supports chemical reactions.

What is the nucleolus and its main function?

A sub-organelle inside the nucleus that assembles ribosomal RNA (rRNA) required for protein synthesis.

What is the nuclear envelope and its role?

A double lipid membrane around the nucleus that protects DNA and regulates molecular passage with the cytoplasm.

What are nuclear pores?

Regulated openings in the nuclear envelope that allow small molecules to pass and control access of larger molecules.

What is nucleoplasm?

A gel-like liquid inside the nucleus containing enzymes and nucleotides for DNA/RNA synthesis; supports chromatin and nucleolus.

What is chromatin and its significance?

DNA, RNA, and protein complex in the nucleus that stores genetic information and condenses into chromosomes during cell division.

What is the mitochondrion's role in the cell?

Powerhouse of the cell; produces ATP via cellular respiration; cristae increase energy production.

What is the rough endoplasmic reticulum (RER) and its function?

Network of membranes with ribosomes that synthesize glycoproteins.

What is the smooth endoplasmic reticulum (SER) and its function?

Network of membranes without ribosomes involved in lipid metabolism and detoxification.

What is the Golgi apparatus responsible for?

Modifies, packages, and sorts proteins and lipids into vesicles for transport.

What are vacuoles and their roles?

Fluid-filled sacs for storage; in plants, the central vacuole maintains turgor pressure for support.

What do lysosomes do?

Contain digestive enzymes to break down macromolecules and debris; waste disposal system (mainly in animal cells).

What is the function of chloroplasts?

Carry out photosynthesis; contain chlorophyll; have grana (stacks of thylakoids) for light reactions.

What distinguishes prokaryotic cells from eukaryotic cells in general?

Prokaryotes lack a nucleus and membrane-bound organelles; DNA is free-floating; usually unicellular and simpler.

What characterizes eukaryotic cells?

Membrane-bound nucleus with DNA and many organelles; compartmentalization; can be multicellular or unicellular.

What is the cytoskeleton and its purpose?

Internal framework of protein filaments that gives shape, provides mechanical support, and enables movement and transport.

What are cilia and their two main functional roles?

Hair-like projections; non-motile cilia act as sensory antennae; motile cilia move fluids or materials across the cell surface.

What are microvilli?

Small projections that increase the cell surface area for absorption and secretion (common in intestinal cells).

What are root hairs and their function?

Specialized extensions of root cells that increase surface area for water and nutrient uptake.

What are flagella and their role?

Long whip-like structures used for cell movement; present in some prokaryotic and eukaryotic cells (e.g., sperm).

What are Archaebacteria and where do they thrive?

Ancient bacteria lacking certain structures; thrive in extreme environments; three groups: methanogens, halophiles, thermophiles.

What are methanogens and where do they typically live?

Produce methane; live in anaerobic environments such as sewage facilities, bogs, and ruminant guts.

What are halophiles?

Organisms that thrive in highly salty environments like salt lakes and seawater pools.

What are thermophiles?

Organisms that live in extremely hot environments such as geothermal vents and hot springs.

What are Eubacteria (True Bacteria) and their key features?

Most numerous bacteria with rigid cell walls containing peptidoglycan; includes motile and non-motile species; diverse roles including pathogens and decomposers.

What is Euglena and what makes it unique?

Genus of mostly unicellular organisms with both animal-like and plant-like traits; moves with flagella and can photosynthesize.

What is Paramecium and why is it important in research?

Ciliate protozoan found in freshwater and marine environments; cilia for movement and feeding; widely used as a model organism.

What are diatoms known for?

Microscopic algae with silica-based, intricate cell walls; important in aquatic ecosystems; called gems of the sea.

What primary roles do fungi play in ecosystems?

Yeasts, molds, and mushrooms; have chitin in cell walls; secrete digestive enzymes; important decomposers and nutrient cyclers.

What is Plantae and what are its major groups mentioned?

Kingdom of plants; autotrophic; include major groups like Oryza Grass Group, Angiospermae, Gymnospermae.

What is the Oryza Grass Group?

Tall grasses such as rice; important carbohydrate sources.

What are Angiospermae?

Largest plant phylum; flowering plants with enclosed seeds.

What are Gymnospermae?

Seed-bearing plants that produce cones instead of flowers; important for timber.

What is Animalia?

Kingdom of animals; multicellular; heterotrophic; capable of movement; no cell walls; highly diverse.