Natural selection<span> and selective breeding can both cause changes in animals and plants. The </span>difference between<span> the two is that </span>natural selection<span> happens naturally, but selective breeding only occurs when humans intervene. For this reason selective breeding is sometimes called </span>artificial selection<span>.</span>
Answer:
There are three main types of blood vessels:
1)Artery ---
i) It is a blood vessel having a thick wall.
ii) It carries blood from the heart to different parts of the body.
iii) On regulatory demand of the body it can dilate or constrict.
iv) It doesn't contain any valve.
v) All arteries carry oxygenated blood except the pulmonary artery.
2)Vein ---
i) It is a blood vessel having a thin wall.
ii) It brings blood from different parts to the heart.
iii) It can't dilate or constrict under normal conditions.
iv) It contains valves that allow the blood to flow in one direction towards the heart.
v) All veins carry deoxygenated blood except the pulmonary vein.
3)Capillary ---
i) It is a very narrow blood vessel that has very thin walls.
ii) It forms a network throughout the body in all living cells connecting arteries to veins.
iii) It can dilate or constrict according to the requirement of tissue.
iv) It doesn't have any valve.
v) It contains mixed blood as it connects arteries and veins
Answer:
C. Ethanol, ammonium chloride, phosphate buffer, magnesium sulfate, calcium chloride, trace elements
Explanation:
Acetobacter must have a sufficient supply of oxygen and cannot grow in its absence. Colonies of acetobacter can be detected by a culture media containing ethanol as carbon source, the acid produce by the bacteria will dissolve the chalk thereby leaving a clear zone around the colony.
Answer and Explanation:
Nondisjunction occurs when homologous chromosomes fail to segregate during anaphase I or sister chromatids fail to segregate during anaphase II. The result is an addition or loss of one or more chromosomes. Nondisjunction is associated with disorders like Down's syndrome due to an extra chromosome, Klinefelter's syndrome or Turner's syndrome. These phenomenon where one has three members of homologous chromosome is called trisomy.
