Answer:
Muscle contraction occurs when the thin actin and thick myosin filaments slide past each other. It is generally assumed that this process is driven by cross-bridges which extend from the myosin filaments and cyclically interact with the actin filaments as ATP is hydrolysed.
One is the presence of villi and microvilli in the small intestines
that increase the surface area for which food is absorbed. Second is the presence
of goblet cells that secrete mucus to prevent self-digestion of the
tract lining. Another is the specialized enzymes in different regions of the digestive tract
that specialize in digesting particular foods.
Answer:
D. All of the above
Explanation:
Neanderthal man (<em>Homo sapiens neanderthalensis</em>):
Their fossils were first obtained from Neander valley in Germany which belonged to late pleistocene epoch. Later many other fossils were recovered from various countries by different paleontologists. Neanderthal man had slightly prognathus face. They walked upright like us and has low brows, receding jaws and high domed heads. The main point of difference from us was that they were much stockier than we are. Their cranial capacity was 1300-1600 cc. They were cave dwellers with humped back. They were also skilled in hunting and skilled predators. The neanderthal man was cannibal and they fashioned the skin into clothing to protect themselves from harsh climate conditions. Its also believed that they buried their dead ones with flowers and tools. <em>Homo sapiens neanderthalensis</em> did not evolve into <em>homo sapiens</em>. <em>Cro magnon</em> was the direct ancestor of the living modern man.
1) The antibodies destroy the antigen (pathogen) which is then swallowed and digested by macrophages.
2) White blood cells can produce antitoxins which destroy the toxins that are otherwise known as poison.
Answer:
C. A Landslide Caused By Cattle Overgrazing
Explanation:
This is the only scenario that represents a biotic factor. All other options are caused by natural disasters.
