Organeles specialization
This organelle’s double membrane, studded with pores, protects the cell’s DNA and controls which molecules, like mRNA, can pass in and out.
What is the nucleus?
This process, by which unspecialized cells become structurally and functionally adapted for a particular role, gives rise to muscle, nerve, and blood cells
What is differentiation (cell differentiation)?
These cells can divide repeatedly and develop into specialized cell types.
What are stem cells?
Only 7–8 µm in diameter, this biconcave cell has no nucleus at maturity; its small, flexible shape gives it a high surface-area-to-volume ratio for gas exchange and lets it squeeze through narrow capillaries.
What is a red blood cell?
Found in the zygote and the first few divisions of the embryo, these stem cells can differentiate into any cell type in the body, including the cells of the placenta.
What are totipotent stem cells?
Found free in the cytoplasm or attached to the rough ER, these tiny structures made of rRNA and protein specialize in translating mRNA into polypeptides.
What are ribosomes?
Because a cell handles only one task, it can perform that task with greater efficiency and precision. This is the key advantage of this division of labor among cells.
What is (cell) specialization?
These are the two main properties about stem cells: one is that allow stem cells to maintain their population.
What self-renewal?
Its head is only about 4–5 µm long, but its flagellum brings the whole cell to roughly 50–55 µm; this streamlined size and shape help it swim toward the egg.
What is a sperm cell?
These long, multinucleated fibres are packed with myofibrils made of repeating sarcomeres, which give them their banded appearance and allow rapid, powerful contraction.
What are striated (skeletal) muscle cells?
These small membrane-bound sacs specialize in transporting and storing materials, such as proteins moving from the Golgi apparatus to the plasma membrane for release by exocytosis.
What are vesicles?
These are the characteristics of a whole organism, such as consciousness or coordinated movement, that arise from the interaction of its parts but are not shown by any single part alone.
What are emergent properties?
These are the two main properties of stem cells:one is that allow stem cells to produce specialized cells.
What is differentiation?
These immune cells are generally larger than red blood cells, ranging from about 6–20 µm depending on type, which helps them leave blood vessels and engulf pathogens or produce antibodies.
What is a white blood cell?
After activation, B cells of this type differentiate into plasma cells, which are full of rough ER and Golgi apparatus to mass-produce and secrete antibodies, while T cells of the same type destroy infected cells.
What are lymphocytes?
Muscle cells contain many of these organelles, whose folded inner membranes, called cristae, increase the surface area available for ATP production.
What is the mitochondrion?
In this laboratory technique, a tissue is first homogenized and then spun at increasing speeds, so that the densest and heaviest organelle, the nucleus, settles out first as a pellet.
What is differential centrifugation?
These stem cells can differentiate into almost any cell type in the human body.
What are pluripotent stem cells?
At roughly 100–150 µm in diameter, this is the largest human cell; its large volume stores nutrients for the early embryo.
What is the ovum, or egg cell?
To restore sight after chemical burns, surgeons can transplant tissue from the limbus of the eye, because it supplies the surrounding microenvironment that keeps corneal stem cells alive, dividing, and able to differentiate when needed.
What is a stem cell niche?
Its stacked thylakoids (grana) hold chlorophyll for the light-dependent reactions, while the surrounding stroma hosts the Calvin cycle. Its own DNA and 70S ribosomes support the endosymbiotic theory.
What is the chloroplast?
During differential centrifugation to isolate nuclei, the sample is kept cold, ______, and buffered for these three reasons respectively: to slow enzyme activity, to prevent organelles from bursting or shrinking, and to maintain a stable pH.
What are the reasons for using isotonic solution?
These stem cells are found in adult tissues and can develop into a limited range of related specialized cell types.
What are multipotent stem cells?
Its cell body is not unusually large, but its axon can be about 1 meter long, making it the longest human cell and specially built for rapid long-distance signaling.
What is a motor neuron?
In this technique, tissue is homogenised in a cold, isotonic, buffered solution and then spun at increasing speeds, so that the nuclei pellet first, then mitochondria, then smaller organelles. Each of the three conditions of the solution protects the organelles in a different way.
What is cell fractionation (differential centrifugation)?