Biology

Plant Transport and Physiology

1,834 Questions

Access a comprehensive set of questions on plant transport mechanisms and physiological adaptations. Topics include water movement, translocation of food, and plant responses to external stimuli. These biology questions are essential for medical entrance exams and other science competitive tests.

Xylem and phloem transportTranspiration and evaporationPlant adaptationsGeotropic and phototropic responsesWater absorption by rootsRespiration in roots

Plant Transport and Physiology Questions

Multiple choice botany internal structure of root, stem and leaf internal structure of monocot leaf internal structure of leaf (dicot and monocot) anatomy of leaf internal structure of dicot leaf

Isobilateral leaves have stomata on

  1. Both upper and lower surfaces

  2. Upper surface only

  3. Lower surface only

  4. None of the two surfaces
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In isobilateral leaves or monocot leaves, stomata are present on both upper or adaxial epidermis as well as lower epidermis or abaxial epidermis.

So, the correct option is ‘Both upper and lower surfaces’.

Multiple choice water potential water potential and pressure plant water relation transport in plants biology

Cell A and cell B are adjacent plant cells. In cell A, $\psi s$ = - 20 bars and $\psi _p$ = 8 bars. In cell B, $\psi _s$ = - 12 bars and $\psi _p$ = 8 bars. Then ______________.

  1. Water moves from cell A to cell B

  2. There is no movement of water between cell A and cell B

  3. Water moves from cell B to cell A

  4. Equal amount of water is simultaneously exchanged between cell A and cell B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Water potential (Psi_w) = Psi_s + Psi_p. For cell A: -20 + 8 = -12 bars. For cell B: -12 + 8 = -4 bars. Water moves from higher potential (-4) to lower potential (-12), so from B to A.

Multiple choice water potential water potential and pressure plant water relation transport in plants biology

Water will move from the root hair through cortex if the water potentials are _________________________.

  1. Root hair- $0$, Cortex-$0$, Xylem-$0$
  2. Root hair-$-2$, Cortex-$-1$, Xylem-$0$
  3. Root hair-$0$, Cortex-$-1$, Xylem-$-2$
  4. Root hair-$0$, Cortex-$+1$, Xylem-$+2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If a difference in water potential exists between the two regions, spontaneous movement of water will take place, provided the movement can occur between them. The direction of flow will be energetically down hill, that is from the region of higher water potential(root hair) to the region of lower water potential(xylem) via cortex from less negative water potential (e.g., - $1$ kPa) to more negative water potential (e.g., - $2$ kPa).

So, the correct answer is 'Root hair-0,, Cortex-−1, Xylem−2'

Multiple choice water potential water potential and pressure plant water relation transport in plants biology

Choose the correct answers from the alternatives given :
Water potential is generally most negative in

  1. the soil solution

  2. mesophyll cell walls

  3. xylem sap of roots

  4. xylem sap of leaves
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water potential is generally most negative in mesophyll cell walls because water evaporates from the mesophyll cells into the air spaces in the leaf. If the air surrounding the leaf has less water vapor than the air in the intercellular spaces, water vapor will leave the leaf through stomata. Order of water to move through the plant from the soil to the air ( a process called transpiration).

W.P root ---> W.P stem ---> W.P leaf ---> W.P atmosphere.
So, the correct option is 'mesophyll cell walls'.

Multiple choice biology water a precious resource water cycle earth's energy budget bio-geo chemical cycles in nature solar energy and its applications

Water enters atmosphere by

  1. Filtration

  2. Evaporation

  3. Evapo-transpiration

  4. Biosphere
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water enters the atmosphere primarily through evaporation from water bodies and transpiration from plants. Together, these processes are known as evapotranspiration, but evaporation is the most fundamental term for water entering the atmosphere from the surface.

Multiple choice biology water absorption and ascent of sap in plants transport of water across plants habit of plants plant classifications

Which of the following statements are not true?

  1. In CAM plants, stomata open during dark and remain closed during the day
  2. Role of $Na^+$ in stomatal opening is now universally accepted

  3. Water potential of root cells is higher than water potential of soil

  4. Capillarity theory is most accepted theory of water movement through plants

  5. Wall of xylem vessels made up of lignocellulose has strong affinity for water molecules
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice botany root - external morphology root system in plants modifications of root root modifications

In many plants the tap root becomes swollen and assume various forms. Match the following.

Plant Type of Root
A. Carrot 1. Conical
B. Mirabilis  2. Fusiform
C. Radish 3. Napiform
D. Turnip 4. Tuberous

  1. A - 1, B - 4, C - 2, D - 3

  2. A - 2, B - 3, C - 1, D - 4

  3. A - 4, B - 1, C - 3, D - 2

  4. A - 3, B - 2, C - 1, D - 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

1.The conical fleshy tap root resembles a cone, that is, the thickest towards base and gradually tapering towards the apex, e.g., Carrot (Daucus carota) 2.The fusiform fleshy root is like a spindle, that is, thickest roughly in the middle and narrow towards both its base and apex, e.g., Radish (Raphanus sativus). 3.The napiform fleshy root is very thick at the base and is almost spherical. It suddenly thins out towards the apex (top-like), e.g., Turnip (Brassica rapa ) 4.The tuberous roots are those thickened tap roots which do not assume any definite form, e.g., Mirabilis jalapa (Four O’ Clock). So, the correct option is A. (A - 1, B - 4, C - 2, D - 3)

Multiple choice botany root - external morphology root system in plants modifications of root root modifications

Read the following four statements:
(A) A simple experiment called girdling was used to identify the tissue through which food is translocated.
(B) Plant factors that effect transpiration include temperature, light, wind velocity and humidity.
(C) Most of the water flow in root occur via apoplast.
(D) In young root, water directly enters into the xylem vessels.
How many of the above statements are right?

  1. Four

  2. Three

  3. Two

  4. One
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice biology different types of nutrition in plants experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

The leaf is boiled in alcohol for a few minutes using water bath, it is essential because

  1. Alcohol is highly volatile

  2. Alcohol dissolves the chlorophyll and decolourises the leaf.

  3. Alcohol cleans the leaf

  4. Alcohol gives the nutrients to the leaf
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Boiling a leaf in alcohol is a standard procedure in photosynthesis experiments to extract chlorophyll, which allows for the subsequent detection of starch using iodine solution.

Multiple choice biology photosynthesis and respiration experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

A green plant bends towards the source of light when exposed to the light on only one side, it bends towards the source of light as it grows. Which of the following is the best explanation of the phenomenon 

  1. The apices of their stems are attracted by light

  2. They need light for photosynthesis

  3. Some auxins accumulates on the shaded side to induce greater cell elongation on that side

  4. Light stimulates the cells on the illuminated side to increase in length
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Accumulation of auxin as the apex of the plant, which is responsible for the phototropism movement so that plant cells are elongated.

So the correct option is C.

Multiple choice botany how plants grow experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

A beaker is filled with water and twigs of Hydrilla are inserted in the funnel so that the cut ends are in the tube of the funnel and the funnel is put in the water. Then a test tube full of water is inverted over the inverted funnel. Air bubbles from the plant collect at the tip of the tube. This experiment demonstrates that oxygen is evolved during photosynthesis. But, if boiled water is used instead of pond water in which Hydrilla grows, then?

  1. Air bubbles are not produced

  2. Air bubbles are produced in large numbers

  3. Only a few air bubbles are produced

  4. Only one air bubble is produced
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If boiled water is used in the test tube, there will be no air bubbles. This is hydrilla cannot survive the high temperature of boiled water. 

So, option A is the correct answer.

Multiple choice biology mineral nutrition in plants hydroponics hydroculture essential and non-essential mineral elements

In aeroponics, which one of the following absorbs required nutrients to the plant?

  1. Roots

  2. Stem

  3. Leaves

  4. External factors
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Aeroponics is the process of growing plants in an air or mist environment without the use of soil or an aggregate medium. In aeroponics, growing plants are suspended in a closed or semi-closed environment by spraying the plant's roots with an atomized or sprayed, nutrient-rich water solution. 
So the correct option is "roots".