Cell Structure and Function Quiz

Cell Structure and Function

• Cells are the basic units of life, exhibiting diverse structures and functions adapted to their roles.
• Prokaryotic cells (bacteria and archaea) lack a nucleus and membrane-bound organelles.
• Eukaryotic cells (plants, animals, fungi, and protists) possess a nucleus and membrane-bound organelles, compartmentalizing cellular functions.
• Common cellular components include the plasma membrane, cytoplasm, nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, mitochondria, and vacuoles.
• The plasma membrane controls substance passage in and out of the cell.
• The nucleus houses the cell's genetic material (DNA) and directs cellular activities.
• Ribosomes are the protein synthesis sites.
• The endoplasmic reticulum (ER) is involved in protein and lipid production.
• The Golgi apparatus modifies, sorts, and packages proteins for secretion.
• Mitochondria are the sites of cellular respiration, generating energy (ATP).
• Vacuoles store substances and provide structural support.

Cellular Processes

• Cellular respiration breaks down glucose to produce ATP, the cell's energy currency.
• Photosynthesis transforms light energy into chemical energy (glucose) in plant cells.
• Mitosis produces two identical daughter cells, crucial for growth, repair, and asexual reproduction.
• Meiosis creates four genetically diverse daughter cells, vital for sexual reproduction. Each has half the parent cell's chromosomes.
• DNA replication copies a double-stranded DNA molecule to ensure accurate genetic material transmission during cell division.
• Gene expression uses DNA's information to synthesize proteins, a tightly regulated process determining cell traits.
• Transcription, the RNA synthesis using DNA as a template, occurs in the nucleus.
• Translation, protein synthesis based on mRNA codons, happens at ribosomes.
• Cellular transport mechanisms regulate selective material movement across the plasma membrane involving passive (diffusion, osmosis) and active (energy-requiring) processes.

Biological Molecules

• Macromolecules (carbohydrates, lipids, proteins, and nucleic acids) are essential cellular components.
• Carbohydrates provide energy, form structures, and signal.
• Lipids store energy, form membranes (phospholipids), and insulate.
• Proteins perform diverse functions: catalysis (enzymes), transport, support, and signaling.
• Nucleic acids (DNA and RNA) store and transmit genetic information, dictating cell function. DNA carries the genetic code, RNA acts as an intermediate between DNA and proteins.

Ecology

• Ecology studies organisms and their interactions with the environment.
• Levels of organization include populations, communities, ecosystems, and the biosphere.
• Ecosystem interactions include predation, competition, and symbiosis (mutualism, parasitism, commensalism).
• Biogeochemical cycles (carbon, nitrogen) are for nutrient cycling, supporting life.

Evolution

• Evolution is the population's genetic change over time.
• Natural selection favors traits enhancing survival and reproduction.
• Evidence for evolution includes homologous structures, fossil records, and molecular similarities.
• Speciation forms new species through accumulated genetic changes.