Answer : (d)

phloem transports organic materials from sites of production (called a source) to a site of need (called a sink). Thus, the typical direction of transport is downward from the primary source (leaves) to the major sink (roots). Answer : (a)

Xylem is associated with tanslocation of mainly water, mineral salts, some organic nitrogen and hormones. Answer : (d)

When a plant cell is placed in a hypotonic solution, water enters into a cell by osmosis and as a result turgor pressure develops. The cell membrane becomes stretched and the osmotic pressure of the cell decreases Thus Osmosis is the reason for asswertion Answer : (c)

The process of guttation occurs when the roots of a plant absorb water from the soil. This creates a pressure inside the plant, and the water is forced out through the hydathodes. Answer : (a)

Surface tension, which occurs because hydrogen bonding between water molecules is stronger at the air-water interface than among molecules within the water. Surface tension not connected with transport across the cell membrane. Answer : (d)

Osmosis is the term used to refer specifically to the diffusion of water (solvent) across a differentially- or semi-permeable membrane. Osmosis occurs spontaneously in response to a driving force Answer : (b)

Osmosis is how plants are able to absorb water from soil. Active transport is a mode of transportation in plants, which uses stored energy to move the particles against the concentration gradient.Uptake of mineral ions into root hair cells of plants. Diffusion is a very important process for photosynthesis where carbon dioxide from the stomata diffuses into the leaves and finally into the cells. Answer : (d)

Guttation is the exudation of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses, and a number of fungi. Answer : (b)

When the potassium (K + ) concentration is high, water moves in, and the stoma opens. -When potassium leaves the guard cells, the stomata close. Pure water have the greatest water potential. and higher concentration of K+ reduces water potential Thus water will enter stomata due to decreased water potential in stomata Answer : (a)

Plasmolysis is when plant cells lose water after being placed in a solution that has a higher concentration of solutes than the cell does. In the biological fields, hypertonic solution is one where the concentration of solutes is greater outside the cell than inside it Thus when cell is keept in hypertonic solution water comes out by the process of osmosis Answer : (c)

Several environmental factors affect stomata opening, including hormone, light quality and intensity, air humidity, atmospheric CO2 concentration, biotic and abiotic stresses. Answer : (b)

The measure of the relative tendency of water to move from one area to another, Adding solute lowers the water potential. Answer : (d)

Turgidity is the state of being turgid or swollen, especially due to high fluid content. Turgidity is essential in plant cells to make them keep standing upright. wall pressure is the mechanical pressure applied to the proptoplast and vacuole by the stretched cell wall. the pressure exerted on the contents of a plant cell by the cell wall that is equal in force and opposite in direction to the turgor pressure Thus if With rise in turgidity, wall pressure will increase Answer : (b)

Endosmosis osmosis toward the inside of a cell or vessel. Given that cell have more concentration of solute and less concentration of water option "a" correct Answer : (a)

Vapour-pressure deficit or VPD, is the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated. as the VPD increases, the plant needs to draw more water from its roots Answer : (d)

In pickel comman salt is added. Thus concentration of solute is more than the concentration of solute in cell. Water comes out of cell Plasmolysis is when cells lose water after being placed in a solution that has a higher concentration of solutes than the cell does. Answer : (a)

The guard cells contain chloroplasts, so they can manufacture food by photosynthesis (The epidermal cells do not contain chloroplasts) Guard cells are the only epidermal cells that can make sugar. Answer : (d)

Cell expansion and an increase in turgor pressure is due to inward diffusion of water into the cell, and turgor pressure increases due to the increasing volume of vacuolar sap. Answer : (b)

Primary transfusion tissue present just on either side of the centrally located vascular bundle. Transfusion tissue is universal in leaves of gymnosperms. It is composed of three kinds of cells: thick walled tracheids, parenchyma and albuminous cells Answer : (c)

Cohesion refers to the attraction of molecules for other molecules of the same kind, Answer : (a)

Wilting that occurs in hot weather when the rate of transpiration exceeds the rate at which a plant can absorb moisture from the soil. Answer : (b)

The correct option is (c) DPD =OP.  When a cell is fully turgid, its OP is equal to TP and DPD is zero. Turgid cells cannot absorb any more water. DPD can be calculated as DPD = Osmotic Pressure - Turgor Pressure. In a plasmolysed cell, cell membrane shrinks away from the cell. Hence gradient develops between the cell and outer solution. Turgor pressure of cell becomes zero. Thus DPD equals to OP. Answer : (c)

A hypotonic solution has a lower concentration of solutes than sap of cell. When cell is placed in hypotonic solution, solvant or water enters the cell Answer : (b)

potassium is responsible for stomata opening statement b is not correct The internal water potential of a plant cell is more negative than pure water because of the cytoplasm's high solute content. Because of this difference in water potential, water will move from the soil into a plant's root cells via the process of osmosis. Statement "c" is not correct The cohesion – tension theory of sap ascent explains how how water is pulled up from the roots to the top of the plant.Statement "d" is not correct Answer : (b)

The mechanism of the closing and opening of the stomata depends upon the presence of sugar and starch in the guard cells. During day time or in the presence of light, the guard cells of the stomata contain sugar synthesized by their chloroplasts. The sugar is soluble and increases the concentration of the sap of guard cells. Due to higher concentration of the cytoplasm of guard cells, the water comes to them from the neighbouring cells by osmosis and they become turgid. With the result the stomata remain open In the night or in the absence of light the sugar present in guard cells converts into the starch. The starch is insoluble, and this way the cell sap of the guard cells remains of much lower concentration than those of neighbouring cells, and the neighbouring cells take out the water from the guard cells by osmosis making them flaccid and the stomata closed. Also when guard cells lose potassium ions, water diffuses out of the cells by osmosis. As water leaves the cells, they become flaccid and less bowed, which closes the stomata between them Answer : (a)

if solution is a very dilute solution, the cell will gain water by osmosis called endosmosis and cell becomes turgid. Answer : (c)

Diffusion pressure deficit (DPD) Osmotic pressure (OP) Turgor pressure (TP) DPD = O.P. - T.P If DPD of first cell is more , it has less water then second and, therefore, water would diffuse from cell Second into the cell First Cell A DPD = 10-5=5 Cell B DPD = 15-12 = 3 Since DPD of cell A is more less water than cell B Water will flow from Cell B to Cell A Answer : (c)

When water enters the cell of a plant, the cytoplasm exerts an outward pressure on the wall and that pressure is called turgor pressure. Cell wall is rigid and flexible therefore exerts an equal and opposite wall pressure against the expanding protoplasm. Thus, turgor pressure becomes equal to the wall pressure when no exchange of water takes place and equilibrium is established. Answer : (c)

Dry seeds when placed in water swell up due to imbibition. Answer : (a)