Animal and Plant Cells Quiz

Animal and Plant Cells

• Animal and plant cells are both eukaryotic cells.
• Both animal and plant cells contain a cell membrane, mitochondria, ribosomes, cytoplasm, and a nucleus.
• Plant cells uniquely have a permanent vacuole, chloroplasts, and a cell wall. Plant cell walls are made of cellulose.
• The vacuole in plant cells stores water and maintains cell shape.
• Chloroplasts are the sites of photosynthesis, converting light energy to chemical energy.
• The cell wall provides structural support and rigidity to plant cells.
• Exam questions commonly assess similarities and differences between animal and plant cells.

Subcellular Structures

• Each subcellular structure plays a specific role in the cell.
• Cell Membrane: Controls the movement of substances in and out of the cell.
• Cytoplasm: A gel-like substance where chemical reactions take place.
• Nucleus: Contains the cell's DNA and controls cellular activities.
• Mitochondria: The sites of aerobic respiration.
• Ribosomes: Sites of protein synthesis, translating mRNA into proteins.
• Permanent Vacuole: A large, fluid-filled sac in plant cells, storing water, nutrients, and waste, maintaining turgor pressure.
• Chloroplasts: Sites of photosynthesis in plant cells, converting light energy to chemical energy. They contain chlorophyll.
• Cell Wall: A rigid structure that supports and protects the plant cell, made of cellulose.

Bacterial Cells

• Bacterial cells are prokaryotic cells, much smaller than eukaryotic cells.
• Prokaryotic cells lack a nucleus and membrane-bound organelles (mitochondria, ribosomes, chloroplasts, vacuoles).
• They contain a single DNA loop and plasmids in their cytoplasm.
• Plasmids are small, circular DNA molecules that replicate independently carrying genes (antibiotic resistance, etc.).
• Prokaryotes are single-celled organisms.

Microscopes

• Light and electron microscopes are the two main types.
• Light microscopes, common in schools, use visible light to illuminate specimens.
• Electron microscopes use electron beams for highly magnified and detailed images.
• Electron microscopes have greater magnification and resolution, enabling observation of smaller structures in cells.
• Electron microscopes require dead specimens. Light microscopes can use living or non-living specimens.
• I (image size) = M (magnification) × A (actual size)

Cell Specialization and Stem Cells

• Cell specialization is the process of cell differentiation for specific functions.
• Examples include nerve cells (neurons), fat cells (adipocytes), muscle cells (myocytes), brain cells (neurons), root hair cells, red blood cells, and sperm cells.
• Stem cells are undifferentiated cells capable of developing into various specialized cells.
• Embryonic stem cells: Totipotent – can become any cell type.
• Adult stem cells: Multipotent – can become most cell types.
• Stem cells are crucial in research and potential treatments for diseases.

Mitosis and the Cell Cycle

• Mitosis produces two genetically identical daughter cells from one parent cell.
• The cell cycle has two main phases: interphase and mitosis.
• Interphase: Cell growth and DNA duplication.
• Mitosis:
  • DNA duplication
  • Chromosome alignment
  • Chromosome separation to opposite poles
  • Nuclei reformation at each side of cell
  • Cell membrane splitting, creating two daughter cells.

Cell Transport

• Cell transport moves substances across the cell membrane.
• Passive Transport (no energy):
  • Diffusion: Movement from high to low concentration (e.g., oxygen from lungs to blood).
  • Osmosis: Water diffusion across a selectively permeable membrane (e.g., water absorption in the large intestine).
• Active Transport (energy required): Movement from low to high concentration (e.g., nutrient uptake by root hair cells).

Factors Affecting Cell Transport

• Surface area: Larger surface area speeds transport.
• Temperature: Higher temperature increases molecule speed, thus increasing transport rate.
• Diffusion pathway: Shorter pathway leads to faster transport.
• Blood supply: Constant concentration gradient enhances transport.
• Concentration gradient: Steep concentration gradient leads to faster transport.
• Steepness of concentration gradient: A greater difference in concentration speeds up transport.

Test your knowledge on the similarities and differences between animal and plant cells. This quiz covers key concepts such as cell structures, their functions, and the unique features of plant cells like chloroplasts and cell walls. Perfect for students learning about eukaryotic cells.