Answer:
<h2>
Through production of news cell-surface proteins with a different molecular structure by each new generation. Letter B</h2>
Explanation:
The life cycle of theses paratises extracellular alternate between the salivary glands of the insect transmitter and the blood of the mammal. During the set prior to the entry into the host, the metacylic parasites express a dense over formed by the Variant Surface of Glycoprotein, after entering to the mammal host they transform into a morphology that stays in the bloodstream.
<em>The parasites have to manipulate hosts cells in order to avoid the production of antimicrobial molecules and to benefit from growth factor production.</em>
<em>Intracellular protozoa have a remarkable adaptive capacity as they are able to resist killing by remodelling the phagosomal compartments where they reside and by interfering with the signalling pathway that leads to cellular activation. </em>
When was BSE first discovered?
BSE first appeared in British cattle in the mid-1980s. There have been numerous cases detected in other countries. A complete list of countries is available from both the U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA).
Answer: Large molecules and wastes move through the membrane through forms of active transport- endocytosis and exocytosis.
Explanation:
Molecules are moved across the cell membrane via different mechanisms like diffusion, facilitated diffusion and passive transport; however, some very large molecules require specialized types of active transport to cross over- these are endocytosis and exocytosis.
During endocytosis large molecules cells and cell fragments moved across the plasma membrane through a process of <em>invagination;</em> piece of the external cell membrane falls into itself and forms a small pocket that surrounds the target molecule this breaks off from the membrane to form an intracellular vesicle. Different methods of endocytosis such as <em>phagocytosis, pinocytosis </em>and receptor-mediated <em>endocytosis</em>, take in cells, water and targeted substances respectively.
Like endocytosis, the particles (signal proteins, neurotransmitters and waste material) are surrounded by a phospholipid membrane. However, in exocytosis, this membrane is formed in the cytoplasm, and merges with the plasma membrane’s interior in a process <em>opposite to </em>endocytosis; material is removed from the cell and exported into the cell’s exterior called the extracellular space.
Answer:
C. Cohesion of molecules
Explanation:
Cohesion is the interaction of molecules of the same substance together. By the force of cohesion if two drops of water come together they form one. Water has high rates of cohesion due to hydrogen bonds.
This phenomenon also called surface tension and is what allows small insects to stand on water.
Cohesion along with adhesion of water to the walls of the narrow tube generate what is called capillarity. This allows liquids to ascend inside the narrow tubes. As long as the cohesion is less than the adhesion, the liquid will rise until both forces are equal.
