Scientists and Apparatus concerned Questions in English

(B) The $Cobalt$ $chloride$ paper method is used to determine the position and frequency of stomata on the leaf surface.
In its anhydrous state,$Cobalt$ $chloride$ paper is blue in color.
When placed on the leaf surface,it absorbs the water vapor released during transpiration.
As it absorbs moisture,the paper changes its color from blue to pink.
The rate of color change indicates the density and distribution of stomata on the leaf surface.

(A) The $Cobalt$ $chloride$ $paper$ $method$ is used to compare the rate of transpiration from the two surfaces of a leaf. When $Cobalt$ $chloride$ paper is placed on the upper and lower surfaces of a dorsi-ventral leaf,it turns from blue to pink due to the absorption of water vapor. The rate of color change indicates the relative amount of water loss (transpiration) from each surface.

(A) The unequal loss of water (transpiration) from the two surfaces of a dorsi-ventral leaf can be determined using $Cobalt \ chloride$ paper.
$Cobalt \ chloride$ paper is blue when dry and turns pink when it absorbs moisture.
By placing this paper on both the upper and lower surfaces of the leaf,the rate of transpiration can be compared based on the speed at which the paper changes color from blue to pink.

(B) The correct answer is $B$.
Linsbauer $(1916)$ proposed that the opening and closing of stomata are regulated by changes in the permeability of the guard cell membranes.
He suggested that the removal of $CO_2$ during photosynthesis alters the permeability of guard cells to various solutes,which influences the osmotic pressure and leads to stomatal movement.

(A) The pressure bomb technique,also known as the pressure chamber method,was first developed and used by Scholander et al. in $1965$.
This apparatus is used to measure the water potential of plant tissues by applying external pressure to balance the tension in the xylem sap.

(C) potometer is an apparatus used to measure the rate of water uptake by a cut shoot.
It is based on the principle that the rate of water absorption by a plant is approximately equal to the rate of transpiration.
As the plant loses water through transpiration,it absorbs an equivalent amount of water from the potometer,which can be measured by the movement of an air bubble in the capillary tube.

(A) The concept that "transpiration is a necessary evil" was proposed by the scientist $Curtis$.
Transpiration is considered 'necessary' because it is essential for the upward movement of water and minerals (ascent of sap) and for cooling the plant surface.
It is considered an 'evil' because excessive transpiration can lead to water stress and wilting in plants, especially under conditions of water scarcity.

(D) An osmoscope is a simple laboratory apparatus designed to demonstrate the process of osmosis. It typically consists of a thistle funnel covered with a semi-permeable membrane,which is placed in a beaker containing water. As water enters the funnel due to osmosis,the level of the solution inside the funnel rises,visually demonstrating the movement of solvent molecules across a semi-permeable membrane.

(B) $Potometer$ is an apparatus used to measure the rate of water uptake by a leafy shoot,which is indirectly proportional to the rate of transpiration.
$Porometer$ is used to measure the size of stomatal aperture.
$Auxanometer$ is used to measure the growth in length of a plant.
$Tensiometer$ is used to measure the soil water tension or matric potential.

(C) The apparatus used to measure the rate of transpiration and the degree of stomatal opening is known as the potometer.
Specifically,the porometer,which is a type of potometer used to measure the degree of stomatal opening,was devised by Francis Darwin and $D$.$F$.$M$. Pertz.
Therefore,the correct answer is $Darwin$.

(D) $Potometer$ is an apparatus used to measure the rate of $Transpiration$ in a plant.
$A$ $Clinostat$ is a device used to study the effect of gravity on plant growth,specifically $Geotropism$,by rotating the plant to eliminate the directional influence of gravity.
Therefore,the correct pair is $Transpiration$ and $Geotropism$.

(A) Darwin's potometer is a specialized apparatus designed to measure the rate of transpiration in plants. Specifically,it is used to compare the rate of transpiration occurring through the stomata (stomatal transpiration) versus the rate occurring through the cuticle (cuticular transpiration). By using this device,researchers can quantify how much water loss is attributed to each pathway.

(B) Root pressure is a positive pressure that develops in the xylem sap of roots of plants.
It is measured using a device called a manometer.
$A$ manometer consists of a $U$-shaped tube containing a liquid (usually mercury or water) that measures the pressure exerted by the root system.
Therefore,the correct option is $B$.

(C) Scholander et al. $(1965)$ were the first to measure the tension (shoot pressure) directly by using the pressure chamber method or pressure bomb technique.
This apparatus allows for the measurement of the water potential of plant tissues by applying external pressure to a leaf or shoot until the xylem sap is forced to the cut surface.

(C) Ganong's potometer is a laboratory apparatus specifically designed to measure the rate of transpiration in a cut shoot.
It works on the principle that the amount of water absorbed by the plant shoot is approximately equal to the amount of water lost through transpiration.
As the plant loses water through its leaves,it creates a suction pressure that pulls water from the potometer,causing the air bubble in the capillary tube to move,which allows for the calculation of the rate of water loss.

(A) Sir $J$.$C$. Bose $(1923)$ proposed the Pulsation theory to explain the ascent of sap in plants.
He suggested that the living cells of the innermost layer of the cortex,located just outside the endodermis,exhibit rhythmic pulsations.
These rhythmic contractions and expansions are responsible for pumping water in an upward direction through the plant body.

(A) The correct matching is as follows:
$(A)$ Relay pump theory was proposed by Godlewski $(r)$.
$(B)$ Transpiration cohesion theory (Cohesion-Tension theory) was proposed by Dixon and Joly $(s)$.
$(C)$ Mass flow hypothesis (Pressure flow hypothesis) was proposed by Ernst Munch $(t)$.
$(D)$ Pulsation theory was proposed by Sir $J$.$C$. Bose $(q)$.
Therefore,the correct combination is $A-r, B-s, C-t, D-q$.

(A) potometer is an apparatus used to measure the rate of transpiration in a leafy shoot. It operates on the principle that the amount of water absorbed by the plant is approximately equal to the amount of water lost through transpiration. By measuring the movement of an air bubble in the capillary tube,we can calculate the volume of water lost by the plant over a specific period.

(A) Mitler $(1958)$ used the aphid stylet technique to collect phloem sap.
In this method,aphids feed on the phloem elements by inserting their fine,needle-like mouthparts,known as stylets,into the sieve tubes of the plant.
Once the stylet is inserted,the aphid is carefully severed from its body,leaving the stylet embedded in the phloem.
The phloem sap then exudes through the stylet due to the positive pressure within the sieve tubes,allowing for the collection and analysis of the sap.

(A) The rate of transpiration is measured using an instrument called a $Potometer$.
$A$ $Potometer$ works on the principle that the amount of water absorbed by a plant shoot is approximately equal to the amount of water lost through transpiration.
$Sphygmomanometer$ is used to measure blood pressure.
$Auxanometer$ is used to measure the rate of growth in plants.
$Respirometer$ is used to measure the rate of respiration.

(A) The Pulsation Theory for the ascent of sap was proposed by $J. C. Bose$. According to this theory,the living cells of the innermost cortical layer of the stem exhibit pulsatory activity,which pumps water upwards through the xylem.

(B) $Potometer$ is an apparatus used to measure the rate of water uptake by a cut shoot,which is directly proportional to the rate of transpiration.
$Auxanometer$ is used to measure the growth in length of a plant.
$Porometer$ is used to measure the size of stomatal apertures.
$Tensiometer$ is used to measure soil water tension.
Therefore,the correct instrument for measuring the rate of transpiration is the $Potometer$.

(N/A) The experimental setup shown is a classic demonstration of the transpiration pull theory.
$1$. The setup consists of a leafy shoot attached to a glass tube filled with air-free water,with the lower end immersed in a beaker containing mercury.
$2$. As transpiration occurs from the leaves of the shoot,water is lost in the form of water vapor.
$3$. This loss of water creates a negative pressure or tension (transpiration pull) in the xylem vessels of the shoot.
$4$. This tension is transmitted down to the water column in the tube,which in turn pulls the mercury up into the tube.
$5$. Therefore,this experiment demonstrates that transpiration generates a significant pulling force (transpiration pull) capable of lifting a water column against gravity,which is the primary mechanism for water transport in plants.

(N/A) The experimental setup shown is a potometer,which is used to measure the rate of transpiration in a leafy shoot.
When a blower is placed close to the setup,it increases the speed of air movement around the leaves.
Increased air movement reduces the humidity around the leaf surface,which in turn increases the rate of transpiration.
As the rate of transpiration increases,the leafy shoot absorbs water more rapidly from the tube.
This increased water uptake creates a stronger pull (transpiration pull),causing the mercury level in the tube to rise.

(N/A) The experimental setup demonstrates the process of transpiration in plants. As the leafy shoot transpires,it creates a suction pressure (transpiration pull) that draws water up the tube,causing the mercury level to rise. Phenyl mercuric acetate is an anti-transpirant. When sprayed on the leaves,it induces the closure of stomata,thereby significantly reducing the rate of transpiration. Consequently,the transpiration pull decreases,and the mercury level will go down (or fail to rise) compared to the control setup.

(A) potometer is a device used to measure the rate of transpiration in plants.
It operates on the principle that the amount of water absorbed by the plant is approximately equal to the amount of water lost through transpiration.
Therefore,by measuring the rate of water uptake,we can indirectly determine the rate of transpiration.

(A) The rate of transpiration is measured using a $Potometer$ (such as $Farmer's$ $Potometer$ or $Ganong's$ $Potometer$).
These instruments are based on the principle that the rate of water absorption is nearly equal to the rate of transpiration.
$A$ $Porometer$ is used to measure the degree of stomatal opening.
An $Auxanometer$ is used to measure the growth in length of a plant.
$A$ $Respirometer$ is used to measure the rate of respiration.

(B) The term 'root pressure' was coined by Stephen Hales. It refers to the positive pressure that develops in the xylem sap of the roots of plants as a result of active absorption of mineral nutrients by the root hairs. This pressure is responsible for pushing water up to small heights in the stem.

(C) The Cohesion-Tension theory,also known as the Transpiration Pull theory,explains the ascent of sap in plants. This theory was proposed by $Dixon$ and $Jolly$ in $1894$. It suggests that the evaporation of water from the leaves (transpiration) creates a negative pressure (tension) in the xylem,which pulls the water column upwards due to the cohesive and adhesive properties of water molecules.