Answer: Option A. "Cytoskeleton"
Explanation:
Cytoskeleton can be defined as the network of protein filaments in the cytoplasm eukaryotic cells interlinking from cell nucleus to cell membrane.
There are three basic types of protein fibers present in cytoskeleton that includes micro filaments (Actin filaments ), microtubules and intermediate filaments.
Microfilaments are consist many linked monomers of a protein known as actin, that combines in a double helix with a diameter of about 7 nano-meter and functions as serving tracks for myosin (motor protein).
Microtubules are arranged in a form of hollow straw like structure made up of consist of tubulin proteins having diameter of about 25 nano-meter and further consist of two subunits, α-tubulin and β-tubulin.
Intermediate filaments are the cytoskeletal element which are made up of multiple strands of fibrous proteins wounded together having an average diameter of 8 to 10 nano-meter.
Answer:
D. Parasympathetic activity
Explanation:
The parasympathic system is part of the Autonomous Nervous System. They have two types colinergic receptors: muscarinic receptors M1, M2, M3 and M4 and nicotinic receptors. Through M3 receptors, the parasympathetic effect in the male sex organ is erection.
Explanation:
The cell is the smallest structural and functional unit of living organisms, which can exist on its own. Therefore, it is sometimes called the building block of life.
Answer: it is true
Explanation:
Thaey also help to save people in less disastrous situations.