Cell Biology Flashcards
What’s a light microscope’s magnification and resolving power?
Up to x2000 magnification and 200nm resolving power.
What’s an electron microscope’s magnification and resolving power?
Up to x2 000 000 magnification and 0.2nm resolving power.
Image size = ?
Image size = magnification x size of real object
Magnification = size of image divided by size of real object
What cell features are common to all cells?
A nucleus, cytoplasm, cell membrane, mitochondria, and ribosomes.
What are permanent vacuoles filled with?
Sap
Plants and algal cells contain all the structures seen in animal cells as well as a cell wall made of what?
Cellulose
Where do prokaryotes contain their genetic material?
The genetic material is not in a distinct nucleus. It forms a single DNA loop. Prokaryotes may contain one or more extra small rings of DNA called plasmids.
What do cells do to form different types of cells?
Differentiate.
Animal cells may be specialised to function within a…..
Tissue, an organ, organ systems, or whole organisms
Examples of specialised plant cells are….
Root hair cells, photosynthetic cells, xylem cells, and phloem cells
Define diffusion
The spreading of a substance from an area of higher concentration to an area of lower concentration.
What is the rate of diffusion affected by?
Concentration gradient, temperature, and available surface area
Define osmosis
The movement of water from a high concentration to a lower concentration
Why is osmosis important to plant cells?
It is important to maintain turgor
Define active transport
Active transport moves substances against the concentration gradient- from a low concentration to a higher concentration
How does active transport help a plants root hair cells?
Active transport allows plant root hairs to absorb mineral ions required for healthy growth from very dilute solutions in the soil.
What are some adaptations for exchange surfaces?
-Large surface area and thin walls for short diffusion distances
-in animals, an efficient blood supply, or for gaseous exchange, be ventilated
Body cells divide in a series of stages called what?
The cell cycle
Explain mitotic division
-DNA replicates to form two copies of each chromosome and synthesis of new sub-cellular structures
-the nucleus divides
-cell divides into two identical daughter cells
Why is mitotic cell division important?
For growth, repair, and development of multicellular organisms
How can stem cells from plant meristems be used by people?
To produce new plant clones quickly and economically for research, horticulture, and agriculture
