It’s C. The start point of the cycle. I took this on my test
Answer:
The best answer to the question: These cellular structures are utilized in strong involuntary muscle contractions and transmission of electrical impulses, would be: T-Tubules.
Explanation:
In both skeletal and cardiac muscle, not smooth muscle, because of the way that the muscle fibers are conformed into tight bundles of sarcomeres (skeletal muscle) and myocardiocytes (cardiac muscle), there is a need for a series of structures that will ensure that when there is a stimulus from the nervous systems, these stimulus will propagate to all the cells in the fibers, and not just one.
Aside from counting with a neuromuscular motor plate, which will receive the neurotransmitter from the nerve endings and produce the appropriate reactions, as well as propagate that reaction to all the cells that are being stimulated, muscle fibers also have a structure known as T-Tubules. T-Tubules are formations much like roadways of cell plasma membrane that connect not just one, but all the cells within a muscle fiber so that once a stimulus comes, all the cells will initiate the process of calcium release and action potential propagation. These T-Tubules will ensure that electrical impulses reach all muscle cells and that all cells react at the same time as needed.
Answer:
1.Plasma membrane
The plasma membrane surrounds the cell to create a barrier between the cytosol and the extracellular matrix. Plasma membranes also enclose lumens of some cellular organelles.
2.Endoplasmic reticulum
The endoplasmic reticulum (ER) is a large network of membranes responsible for the production of proteins, metabolism and transportation of lipids, and detoxification of poisons. There are two types of endoplasmic reticulum with separate functions: smooth endoplasmic reticulum and rough endoplasmic reticulum. The presence or absence of ribosomes in the ER’s plasma membrane determines whether it is classified as smooth or rough ER.
3.Golgi apparatus
The Golgi apparatus appears as a series of flattened, membranous sacs, or cisternae, that resemble a stack of pancakes just off the rough endoplasmic reticulum. It receives vesicles containing proteins recently produced by the rER. The Golgi apparatus can be compared to a warehouse or post office for newly formed proteins. Here the proteins are further modified, packaged, and sent off to their final destinations in the cell or body.
Answer:
A glance of earth taken from space will depict it blue. This blue colour is actually water, the major part of the earth is covered with water. We need water for almost everything, for example- drinking, bathing, cooking etc and therefore we should know about the properties of water. 65 % human body is composed of water. Water is essential for the survival of life on earth. Water is distributed unevenly on the earth’s surface. It forms a major solvent and dissolves almost every polar solute. So let us have a look at its properties.
Physical properties of water : Water is a colourless and tasteless liquid. The molecules of water have extensive hydrogen bonds resulting in unusual properties in the condensed form. This also leads to high melting and boiling points. As compared to other liquids, water has a higher specific heat, thermal conductivity, surface tension, dipole moment etc. These properties form the reason for its significance in the biosphere. Water is an excellent solvent and therefore it helps in the transportation of ions and molecules required for metabolism. It has a high latent heat of vaporization which helps in the regulation of body temperature
Chemical properties of water: Amphoteric nature:
Water can act as both acid and base, which means that it is amphoteric in nature.
Example:
Acidic Behaviour: H2O(l)+NH3(aq) ⇌ H3O+(aq)+NH+4(aq)
Basic Behavior: H2O(l)+H2S(aq) ⇌ H3O+(aq)+HS−(aq)
Redox reactions:
Electropositive elements reduce water to hydrogen molecule. Thus water is a great source of hydrogen. Let us see an example in this case:
2H2O(l)+2Na(s)→2NaOH(aq)+H2(g)
During the process of photosynthesis, water is oxidized to O2. As water can be oxidized and reduced, it is very useful in redox reactions.
Hydrolysis reaction
Water has a very strong hydrating tendency due to its dielectric constant. It dissolves many ionic compounds. Some covalent and ionic compounds can be hydrolyzed in water.
Explanation:
To bring oxygen in the body because it is a respiratory organ fish
