Answer:
The cells on the cornea are maintained by pheripheral vessels and surrounding fluids.
Explanation:
*- The capillaries of the limbus nourish the peripheral part of the cornea.
*- Tears supply of glucose in the tear film
*- Aqueous humor nourishing the outermost layers of the cornea the endothelium being a unicellular layer
Answer: c. proteasome
Explanation:
Proteasomes are extremely important multi-catalytic proteases and are involved in various cellular functions. The proteasome is an essential component of eukaryotic cells and is responsible for the ATP-dependent proteolytic degradation of most cellular proteins. They are present in the nucleus and cytosol and can represent up to 1% of total cell proteins. Proteasomes generally degrade proteins to small peptides, most of which are rapidly hydrolyzed by cytoplasmic exopeptidases. It catalyzes the rapid degradation of many enzymes, regulatory proteins, and eliminates abnormal proteins resulting from mutation or damaged proteins. The inability of this cellular organelle can lead to neurodegenerative diseases, such as Parkinson´s disease.
Answer:
The heat given off by Earth's core is circulated through mantle convection.
Explanation:
Heating materials usually causes them to <em>expand</em>; as they become hotter, they also become less dense. Convection describes the transfer of heat from hot areas of liquids and gases to cooler ones. This causes the heated, less dense material to rise and more dense material to fall, as it’s pulled by gravity. Super-heated metal forming Earth’s central core heats rock in the mantle; the hot and cool rock slowly rise and sink- this circulation process is called mantle convection.
Answer:RNA polymerase – makes a molecule of RNA from an RNA template
Explanation: RNA polymerase is an enzyme that catalyzes the copying of a DNA sequence into an RNA sequence during transcription. RNA polymerase uses a DNA template for the synthesis of an RNA strand. RNA polymerase is also called DNA-dependent RNA polymerase. During transcription, DNA helicase unwinds the double helix of the DNA while the RNA polymerase catalyzes the synthesis of an RNA strand from the DNA.
Answer:
Symbiosis
Explanation:
Symbiosis is a physical association between two different organisms whereby both benefit from the relationship. A good example is the lichens. These are composite plants consisting of blue-green algae within the mycelial mass of fungus. The algae are provided with a means of attachment. They also obtain water, carbon dioxide and mineral salts from the fungus. The fungus obtains oxygen and carbohydrates made by algae through photosynthesis.
