4.1 Cell biology Flashcards
(41 cards)
What are the key components of plant and animal (eukaryotic) cells?
Plant and animal cells have a cell membrane, cytoplasm, and genetic material enclosed in a nucleus.
How do bacterial cells (prokaryotic) differ from eukaryotic cells?
Bacterial cells are much smaller, have cytoplasm and a cell membrane surrounded by a cell wall, and the genetic material is a single DNA loop without a nucleus. There may be plasmids.
What should students be able to demonstrate regarding cell size and scale?
Students should be able to demonstrate an understanding of the scale and size of cells and perform order of magnitude calculations using standard form.
What are the main parts of most animal cells?
Most animal cells have a nucleus, cytoplasm, cell membrane, mitochondria, and ribosomes.
What additional parts do plant cells have compared to animal cells?
Plant cells have chloroplasts, a permanent vacuole filled with cell sap, and a cell wall made of cellulose.
What is the function of chloroplasts in plant cells?
Chloroplasts carry out photosynthesis in plant cells.
What are plasmids, and where are they found?
Plasmids are small rings of DNA found in bacterial cells. They carry additional genetic information.
What is the function of the nucleus in eukaryotic cells?
The nucleus contains genetic material (DNA), controls the cell’s activities, and is the site of DNA replication and transcription.
How do specialized cells relate to their function in tissues or organs?
Specialized cells like sperm cells, nerve cells, muscle cells in animals, and root hair cells, xylem, and phloem in plants are adapted to perform specific functions.
What is cell differentiation?
Cell differentiation is the process by which cells become specialized for specific functions. Most animal cells differentiate early, while many plant cells can differentiate throughout life.
How is microscopy used to study cells?
Microscopy allows for the study of cells and their sub-cellular structures in greater detail. Electron microscopes have higher magnification and resolution compared to light microscopes.
How is magnification calculated in microscopy?
Magnification = size of image / size of real object. Students should be able to express the answer in standard form when appropriate.
What is binary fission in bacteria?
Binary fission is the process by which bacteria divide, often every 20 minutes under suitable conditions.
What is aseptic technique and why is it important in culturing microorganisms?
Aseptic technique involves sterilizing petri dishes, culture media, and inoculating loops to prevent contamination when culturing microorganisms.
What is the role of stem cells in organisms?
Stem cells are undifferentiated cells capable of forming many different types of cells, playing key roles in growth, repair, and differentiation in both animals and plants.
How do cells divide in the cell cycle?
In the cell cycle, cells grow, replicate their DNA, and then divide into two identical cells through mitosis.
What is the function of chromosomes in cells?
Chromosomes, made of DNA, carry genes and are typically found in pairs in body cells.
What is mitosis, and why is it important?
Mitosis is the process by which a cell divides to form two identical cells, essential for growth and repair in multicellular organisms.
How does diffusion work in cells?
Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration, such as the exchange of gases (oxygen and carbon dioxide) in cells.
What factors affect the rate of diffusion?
The rate of diffusion is affected by the concentration gradient, temperature, and the surface area of the membrane.
What is osmosis?
Osmosis is the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
How does active transport differ from diffusion and osmosis?
Active transport moves substances against the concentration gradient, requiring energy from respiration, while diffusion and osmosis do not require energy.
What is the role of active transport in plant cells?
Active transport allows plants to absorb mineral ions from dilute solutions in the soil, necessary for healthy growth.
How do cells in multicellular organisms exchange materials?
Multicellular organisms have specialized exchange surfaces like the small intestine, lungs, roots, and leaves. These surfaces increase efficiency by having a large surface area, thin membranes, and efficient blood supply or ventilation.
