Q: Movement of water and minerals in the xylem solutes, pressure, gravity, and matric potential are all important for what?   Read this paragraph and choose the correct option from the provided answers:  Movement of Water and Minerals in the Xylem Solutes, pressure, gravity, and matric potential are all important for the transport of water in plants. Water moves from an area of higher total water potential (higher Gibbs free energy) to an area of lower total water potential. Gibbs free energy is the energy associated with a chemical reaction that can be used to do work. This is expressed as ΔΨ. Transpiration is the loss of water from the plant through evaporation at the leaf surface. It is the main driver of water movement in the xylem. Transpiration is caused by the evaporation of water at the leaf–atmosphere interface; it creates negative pressure (tension) equivalent to –2 MPa at the leaf surface. This value varies greatly depending on the vapor pressure deficit, which can be negligible at high relative humidity (RH) and substantial at low RH. Water from the roots is pulled up by this tension. At night, when stomata shut and transpiration stops, the water is held in the stem and leaf by the adhesion of water to the cell walls of the xylem vessels and tracheids, and the cohesion of water molecules to each other. This is called the cohesion–tension theory of sap ascent. Inside the leaf at the cellular level, water on the surface of mesophyll cells saturates the cellulose microfibrils of the primary cell wall. The leaf contains many large intercellular air spaces for the exchange of oxygen for carbon dioxide, which is required for photosynthesis. The wet cell wall is exposed to this leaf internal air space, and the water on the surface of the cells evaporates into the air spaces, decreasing the thin film on the surface of the mesophyll cells. This decrease creates a greater tension on the water in the mesophyll cells (Figure 30.34), thereby increasing the pull on the water in the xylem vessels. The xylem vessels and tracheids are structurally adapted to cope with large changes in pressure. Rings in the vessels maintain their tubular shape, much like the rings on a vacuum cleaner hose keep the hose open while...   Choices:  - produce water transport  - Moving Water Transport  - increase water transport  - plant water transport   A:
plant water transport
(Question)
Q: Most geological activity takes place where?   Read this paragraph and choose the correct option from the provided answers:  Most geological activity takes place at plate boundaries. But some activity does not. Much of this intraplate activity is found at hot spots. Hotspot volcanoes form as plumes of hot magma rise from deep in the mantle.   Choices:  - high altitudes  - ocean floor  - center of plates  - at plate boundaries   A:
(Answer)
at plate boundaries
Ques: Q: What structure is made from dna and protein molecules coiled together?   Read this paragraph and choose the correct option from the provided answers:  As a cell prepares to divide, its DNA first forms one or more structures called chromosomes. A chromosome consists of DNA and protein molecules coiled into a definite shape. Chromosomes are circular in prokaryotes and rodlike in eukaryotes. You can see an example of a human chromosome in Figure below . The rest of the time, DNA looks like a tangled mass of strings. In this form, it would be very difficult to copy and divide.   Choices:  - bacterium  - enzymes  - atoms  - chromosome   A:
Ans: chromosome
(Q).
Q: Plants, fungi, bacteria and archaea cells all have what feature that keeps them rigid that animal cells do not have?   Read this paragraph and choose the correct option from the provided answers:  about how that occurs, in terms of membrane structure. If the influx of water continued unopposed, the membrane would eventually burst like an over-inflated balloon, killing the cell. One strategy to avoid this lethal outcome, adopted by a range of organisms, is to build a semi-rigid “cell wall” exterior to the plasma membrane (→). The synthesis of this cell wall is based on the controlled assembly of macromolecules secreted by the cell through the process of exocytosis (see above). As water passes through the plasma membrane and into the cell (driven by osmosis), the plasma membrane is pressed up against the cell wall. The force exerted by the rigid cell wall on the membrane balances the force of water entering the cell. When the two forces are equal, the net influx of water into the cell stops. Conversely, if the [H2O]outside decreases, this pressure is reduced, the membrane moves away from the cell wall and, because they are only semi-rigid, the walls flex. It is this behavior that causes plants to wilt when they do not get enough water. These are passive behaviors, based on the structure of the cell wall; they are built into the wall as it is assembled. Once the cell wall has been built, a cell with a cell wall does not need to expend energy to resist osmotic effects. Plants, fungi, bacteria and archaea all have cell walls. A number of antibiotics work by disrupting the assembly of bacterial cell walls. This leaves the bacteria osmotically sensitive, water enters these cells until they burst and die. Questions to answer & to ponder: • Make a graph of the water concentration across a typical cellular membrane for an organism living in fresh water; explain what factors influenced your drawing. • Look at this video: https://www. youtube. com/watch?v=VctALENHyyI&feature=youtu. How could you use reverse osmosis to purify water? • Where does the energy involved in moving molecules come from? • Plants and animals are both eukaryotes; how would you decide whether the common ancestor of the eukaryotes had a cell...   Choices:  - cytoplasm  - cell membrane  - plastids  - cell walls   A:
(A).
cell walls
Ques:Q: Lampreys possess a large round sucker, lined with teeth, that surrounds the mouth and is used to feed on what?   Read this paragraph and choose the correct option from the provided answers:  Like hagfish, lampreys also lack scales, but they have fins and a partial backbone. The most striking feature of lampreys is a large round sucker, lined with teeth, that surrounds the mouth (see Figure below ). Lampreys use their sucker to feed on the blood of other fish species.   Choices:  - parasites  - herbivores  - marrow  - blood   A:

Ans:blood
Ques:Q: When sparks from a steel grinder react with oxygen, what do they form?   Read this paragraph and choose the correct option from the provided answers:  The sparks from a steel grinder are molten iron. The iron reacts with oxygen to form iron(III) oxide.   Choices:  - rust  - spontaneous combustion  - steel oxide  - iron oxide   A:

Ans:
iron oxide