Biology: Cells and Microscopes

Cells: Structure and Function

• Cells are the basic units of life, composed of atoms, molecules, organelles, and cytoplasm, and are organized into tissues, organs, organ systems, and organisms.

Characteristics of Life

• Cells exhibit characteristics of life, including growth, metabolism, reproduction, response to stimuli, and evolution.

Types of Cells

• Prokaryotic cells lack a nucleus and cell membrane, but have genetic material (DNA) and cytoplasm.
• Eukaryotic cells have a nucleus, cell membrane, cytoplasm, and genetic material (DNA).
• Plant cells have a cell wall, chloroplasts, and a large vacuole for storage.
• Animal cells have lysosomes for digestion and a centriole for cell division.

Cell Organelles and Their Functions

• Nucleus: stores genetic information/DNA.
• Nucleolus: makes ribosomes.
• Cytoplasm: contains cell contents and acts as a floor for organelles.
• Ribosomes: make proteins.
• Golgi Body: sorts and ships proteins.
• Rough Endoplasmic Reticulum: makes proteins for the endomembrane system.
• Smooth Endoplasmic Reticulum: detoxifies the cell and makes lipids.
• Mitochondria: makes energy ("powerhouse of the cell").
• Cell Membrane: a thin barrier separating the cell from its environment.
• Cell Wall: a rigid barrier protecting the cell (found in plants and prokaryotes).
• Chloroplast: makes food during photosynthesis (found in plants).
• Vacuole: stores water and nutrients.

Microscope Components and Functions

• Revolving Nosepiece (Turret): holds objective lenses and can be rotated to switch between different magnification lenses.
• Coarse Adjustment Knob: responsible for finding the image on the stage and getting the image quickly into focus.
• Diaphragm (or Iris Diaphragm): controls the amount of light that reaches the specimen, adjusting for best illumination.
• Stage Clips: hold the slide in place on the stage to ensure it does not move while observing the specimen.

DNA and RNA

• Deoxyribonucleic Acid (DNA): genetic material containing instructions for cell growth and function.
• Ribonucleic Acid (RNA): involved in protein synthesis and other cellular processes.

Organ Systems

• A group of organs working together to perform complex functions necessary for the survival of the organism.

Explore the basics of cells, their characteristics, and the functions of microscopes in biology. This quiz covers the fundamental concepts of life sciences.