Answer the following question given this paragraph: Many ecosystems have changed because of human actions. The human species is responsible for a range of environmental problems. Q: What is the main function of the cardiovascular system? Choices: - implanatation - digestion - respiration - to transport A:
to transport
(Question)
Answer the following question given this paragraph: Weight is a measure of the force of gravity pulling down on an object. Buoyant force pushes up on an object. Weight and buoyant force together determine whether an object sinks or floats. This is illustrated in Figure below . Q: What is the measure of the force of gravity pulling down on an object called? Choices: - factor - mass - volume - weight A:
(Answer)
weight
Ques: Answer the following question given this paragraph: 12.7 Molecular Transport Phenomena: Diffusion, Osmosis, and Related Processes 62. You can smell perfume very shortly after opening the bottle. To show that it is not reaching your nose by diffusion, calculate the average distance a perfume molecule moves in one second in air, given its diffusion constant D to be 1.0010 6 m 2 /s . What is the ratio of the average distances that oxygen will diffuse in a given time in air and water? Why is this distance less in water (equivalently, why is D less in water)? 64. Oxygen reaches the veinless cornea of the eye by diffusing through its tear layer, which is 0.500-mm thick. How long does it take the average oxygen molecule to do this? 65. (a) Find the average time required for an oxygen molecule to diffuse through a 0.200-mm-thick tear layer on the cornea. 3 (b) How much time is required to diffuse 0.500 cm of oxygen to the cornea if its surface area is 1.00 cm 2 ? 66. Suppose hydrogen and oxygen are diffusing through air. A small amount of each is released simultaneously. How much time passes before the hydrogen is 1.00 s ahead of the oxygen? Such differences in arrival times are used as an analytical tool in gas chromatography. Q: Oxygen reaches what veinless part of the eye by diffusing through its tear layer? Choices: - retina - pupil - membranes - cornea A:
Ans: cornea
(Q).
Answer the following question given this paragraph: Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar. ) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: All polar compounds contain what type of bonds? Choices: - balanced - strong - weak - polar A:
(A).
polar
Ques:Answer the following question given this paragraph: Plants alternate between haploid and diploid generations. Haploid cells have one of each pair of chromosomes. Diploid cells have two of each pair. Q: Plants alternate between haploid and what? Choices: - triploid - monoplooid - monoxoid - diploid A:

Ans:diploid
Answer the following question given this paragraph: A molecule of water ( Figure below ) is made of three atoms bonded together. Two of these atoms are hydrogen and one atom is oxygen. The hydrogen ions have a positive electrical charge. The oxygen atom has a negative electrical charge. The hydrogen atoms are located on one side and the oxygen atom on the other. This means that the side with the hydrogen ions has a slightly positive charge. The other side, the side without the hydrogen ions, has a slightly negative charge. The water molecule is a polar molecule . Q: What molecule is made of two hydrogen atoms and one oxygen atom? Choices: - Oxygen - carbohydrate - lipids - water A:
water