Topic 1.1: lntroduction to Cells Flashcards
What are the three points of the cell theory?
1) Cells make up all living things
2) Cells are the smallest unit of structure and function for an organism
3) All cells must come from other cells
What are the common features cells share?
All living cells have membranes, contain genetic material, have genes that code for enzymes that facilitate chemical reactions, and create their own energy to power activities
What are the exceptions to cell theory?
1) Muscle fibers: have many nuclei within one nuclei (a continuous area since most cells are single units)
2) Fungi: some cells in fungi hyphae that are not separated by internal wall
3) Giant Algae: some unicellular algae can be up to 7 cm in length because it lacks subdivision into separate cells
What is the formula for total magnification?
Total magnification= the objective lens*(eyepiece magnification)
Formula for magnification? (can be used to derive both the magnified size[ruler] or the real size[scale bar])
magnification = (magnified size) / (real size)
What are the functions of life?
Nutrition (obtain food and energy for growth)
Metabolism (chemical reactions to release energy)
Growth (irreversible increase in size)
Response (reacts to stimuli)
Excretion (getting rid of wast products of metabolism)
Homeostasis (keeping optimal internal conditions)
Reproduction (sexual or asexual)
What is the ideal surface area to volume ratio and why?
Having as much surface area with as little as volume as possible so that more substance can be absorbed without having to travel to much in the cell
What are emergent properties?
properties of a group of items that wouldn’t be possible with an individual item (ex: tissues)
What is and what causes cell differentiation?
caused by the expression of only certain genes in some cells causing different cells to have different functions; when certain cells express only some genes (all cells have the same genes) (ex: blood vs nerve cell)
What are the benefits of stem cells?
Beneficial for therapeutic purposes (health), and non therapeutic uses; can be used to replace damaged/defective organs or tissues.
What are the three different kind of stem cells?
Embryonic stem cells, cord blood stem cells and adult stem cells
What are two examples of diseases that use stem cells as treatment?
Stargardt’s disease (affects the eyes) and Leukemia (affects blood cells)
What are the ethical consideration fo embryonic stem cells?
Almost unlimited growth potential, can differentiate into any type, more risk of becoming tumor cells, less change of genetic damage, likely to be genetically different from an adult patient receiving the tissue, removal of cells from the embryo can kill it
What are the ethical consideration of cord blood stem cells?
Easy obtained and stored, commercial collection and storage services already available, fully compatible with the tissues of the adult that grow from the baby (no rejection problems), limited capacity to differentiate into different cell types, limited quantities of stem cells, the umbilical cord is discarded either way
What are the ethical considerations of adult stem cells?
Difficult to obtain as there are few and they are deep in tissues, less growth potential, less chance of malignant tumors, limited capacity to differentiate, fully compatible with the adult’s tissue, removal of stem cells does not kill the adult
