Environmental, agricultural, and natural ecosystems.
Answer:
The behavior of chromosomes during meiosis and fertilization is responsible for most of the variation that arises in each generation. Three mechanisms contribute to genetic variation arising from sexual reproduction: independent assortment of chromosomes, crossing over, and random fertilization.
Answer:
all the muscles.
Explanation:
The muscular system is composed of all muscles in the body. The main function of the muscles is to produce movement in different parts, voluntary or involuntary, creating equilibrium. Muscles are made of myocytes. There are three types of muscles: smooth muscle, skeletal muscle, and myocardium.
- The smooth muscle is formed by fusiform cells, mononucleated, and no transversal striations. There is a protein contraction system, but not as organized as the one of the skeletal muscle.
Smooth-muscle can be found in organs, vessels, veins, and arteries. It provides sustained contractions, slow and rhythmical, but not voluntary.
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Skeletal muscle is the most abundant muscle in vertebrates, constituting the somatic musculature. It proportionates motion to extremities and digits and is responsible for the position and posture of the individual. It is also involved in eye movements, respiration, mastication, deglutition, and phonation. It moves the tongue, the superior esophagus, and the pharynx.
The skeletal muscle is innervated by axons of the motor neurons coming from the CNS. The contraction of the skeletal muscle is voluntary and fast.
Cells composing the striated muscle are significantly long and multinucleated. They arrange in bundles, where cells are parallel to each other.
- Myocardium tissue is more similar to the striated tissue than to the smooth one. However, there are some differences between them. Cardiac cells are cylindrical and smaller, with ramifications. Cardiac cells only have one nucleus, and occasionally there can be two. Actin and myosin filaments are arranged just as the skeletal ones, and the contraction of cardiac cells is molecularly very similar to the skeletal
He was looking through a microscope at particles trapped in cavities inside pollen grains in water. The concept of Brownian motion is named after him. This is the random motion of particles suspended in a fluid, liquid or gas resulting from their collision with the fast-moving molecules. Here, the patterns of motion of the particles are typically alternations between random fluctuations in a particle's position inside a fluid sub-domain with a relocation to another sub-domain. Each relocation is followed by more fluctuations within the new closed volume.
