1.
In guttation process, plants can ……
Correct Answer
D. Get rid of excess of water
Explanation
Guttation is the process by which plants excrete excess water in the form of droplets through special openings called hydathodes. This process occurs when the rate of water absorption by the roots exceeds the rate of transpiration. Therefore, the correct answer is "Get rid of excess of water."
2.
What are lenticels?
Correct Answer
C. Openings in the bark
Explanation
Lenticels are openings in the bark of plants that allow for gas exchange between the internal tissues and the external environment. They are typically found in woody stems and branches and serve as a pathway for oxygen to enter and carbon dioxide to exit the plant. Lenticels also play a role in the release of excess water vapor.
3.
Wilting occurs due to excessive .......
Correct Answer
C. Transpiration
Explanation
Wilting occurs due to excessive transpiration. Transpiration is the process by which plants lose water from their leaves through small openings called stomata. When there is excessive transpiration, the rate of water loss from the leaves is higher than the rate at which water is absorbed by the roots. This leads to a water deficit in the plant, causing the cells to lose turgidity and the plant to wilt.
4.
Which of the following is NOT true about catabolic wastes in plants cells?
Correct Answer
D. Organic acids are reused in building up sugars.
Explanation
Organic acids are not reused in building up sugars in plant cells. Instead, they are usually broken down further or excreted as waste products.
5.
Read the two statements carefully then answer the question.
1. Guttation occurs by a pushing force
2. Transpiration occurs by a pulling force.
Which statement(s) is correct and which is incorrect?
Correct Answer
D. Both are correct
Explanation
Guttation is the process by which water is excreted from the leaves of plants through specialized structures called hydathodes. This process occurs due to a pushing force, as water is forced out of the plant through pressure buildup in the xylem. On the other hand, transpiration is the process by which water is lost from the leaves of plants through small openings called stomata. This process occurs due to a pulling force, as water molecules evaporate from the leaves and create a negative pressure gradient that pulls more water up from the roots. Therefore, statement 1 is correct in stating that guttation occurs by a pushing force, and statement 2 is correct in stating that transpiration occurs by a pulling force.
6.
The plant excretes the excess water through …..
Correct Answer
C. Transpiration and guttation
Explanation
Transpiration is the process by which plants release water vapor through small openings called stomata on their leaves. This helps in the regulation of temperature and the transportation of nutrients. Guttation, on the other hand, is the process by which plants release excess water in the form of droplets through specialized structures called hydathodes. Both transpiration and guttation are mechanisms used by plants to get rid of excess water, making the answer "Transpiration and guttation" the correct choice.
7.
The following are some features of some plants
- They lose a lot of water through transpiration
- Their leaves are always broad and flat
- They lose very little water through transpiration
- Their roots grow very deep into the soil
Which of the following combinations is typical of desert plants?
Correct Answer
D. (3) and (4)
Explanation
Desert plants typically have adaptations that allow them to conserve water in their arid environment. They have specialized leaves that are small and often needle-like, reducing the surface area for transpiration and minimizing water loss. Additionally, desert plants have deep root systems that enable them to access water sources deep underground. Therefore, the combination of losing very little water through transpiration (3) and having roots that grow very deep into the soil (4) is typical of desert plants.
8.
In the experiment shown below, if you cut a transverse section of the stem with a razor and place it on a slide then study it under the microscope. What is your observation? It is observed that .......
Correct Answer
A. Only xylem has taken the stain.
Explanation
When a transverse section of the stem is cut and placed on a slide, and then observed under a microscope, it is observed that only the xylem has taken the stain. This suggests that the xylem tissue has a higher affinity for the stain compared to the other tissues present in the stem section. The xylem tissue is responsible for the transport of water and minerals from the roots to the rest of the plant, and its staining indicates its presence and functionality in the stem.
9.
Why do plants produce both carbon dioxide and oxygen?
Correct Answer
A. Carbon dioxide is a waste product of respiration and oxygen is a waste product of pHotosynthesis
Explanation
Plants produce both carbon dioxide and oxygen because carbon dioxide is a waste product of respiration, which occurs in plant cells, and oxygen is a waste product of photosynthesis, which also occurs in plant cells. During respiration, plants break down glucose to release energy, producing carbon dioxide as a byproduct. In photosynthesis, plants use sunlight to convert carbon dioxide and water into glucose and oxygen. Therefore, plants produce both carbon dioxide and oxygen as waste products of these essential processes.
10.
In summer afternoon rate of transpiration is greater than that of absorption. Then what happens to plants?
Correct Answer
A. Temporary wilting.
Explanation
In summer afternoons, the rate of transpiration in plants is higher than the rate of absorption. This means that plants lose more water through their leaves than they can take up from the soil. As a result, the plants may experience temporary wilting, where their leaves droop and become limp. This is a defense mechanism to reduce water loss and conserve moisture. However, once the temperature cools down or water availability increases, the plants will recover and regain their turgidity.
11.
Which condition(s) favor "Guttation"?
Correct Answer
D. 4. Both (1) and (3)
Explanation
Guttation is the process by which water droplets are exuded from the tips or edges of leaves. It occurs when there is a high rate of water absorption by the roots and a low rate of transpiration from the leaves. When water absorption is high, the roots take up more water than the plant can transpire, leading to excess water being pushed out through specialized structures called hydathodes. Similarly, when transpiration is low, there is less water loss from the leaves, allowing excess water to accumulate and be released through guttation. Therefore, both high water absorption (1) and low transpiration (3) conditions favor guttation.
12.
In the experiment shown below, say what will happen to hydrous copper sulphate if it is added to the water drops.
Correct Answer
A. Its colour will remain the same.
Explanation
When hydrous copper sulphate is added to water drops, its color will remain the same. This is because hydrous copper sulphate is a blue compound, and when it dissolves in water, it forms copper ions (Cu2+) and sulphate ions (SO4^2-). The presence of water does not cause any chemical reaction that would change the color of the copper ions. Therefore, the color of the hydrous copper sulphate remains unchanged.
13.
Which of the following is an important function of stomata in a leaf?
Correct Answer
B. Allowing gaseous waste products to leave the plant
Explanation
Stomata are small openings on the surface of leaves that allow for gas exchange. They play a crucial role in regulating the entry and exit of gases, such as oxygen and carbon dioxide, in plants. By allowing gaseous waste products, such as oxygen, to leave the plant, stomata help maintain proper gas balance and prevent the buildup of harmful gases. This function is essential for the survival of plants, as it ensures the removal of waste products produced during cellular respiration and photosynthesis.
14.
Which is untrue for excretion process in plants?
Correct Answer
C. The rate of catabolism of some Cotton plants weighing 50 kilograms is nearly equal to that of a Sheep having a weight of 50 kilograms too.
Explanation
The statement that the rate of catabolism of some Cotton plants weighing 50 kilograms is nearly equal to that of a Sheep having a weight of 50 kilograms is untrue for the excretion process in plants. This is because catabolism refers to the breakdown of complex molecules into simpler ones, which is not directly related to excretion. The rate of catabolism in plants and animals can vary significantly due to differences in metabolic processes and physiological characteristics. Therefore, comparing the catabolism rate of cotton plants to that of a sheep is not accurate in the context of excretion.
15.
Mangrove trees shown below live in salty water up to 100 times saltier than most other plants can tolerate.Salt water can kill plants. So how do mangroves survive under such dislike conditions?
Correct Answer
D. All of them.
Explanation
All of the given options explain how mangrove trees are able to survive in salty water. The first option states that mangroves squeeze out extra salt through special pores in their leaves, which helps them tolerate the high salt levels. The second option mentions that mangroves have a substance in their roots that filters out a large percentage of the salt in seawater, allowing them to take in only the necessary amount. The third option explains that mangroves concentrate salt in older leaves, which are eventually shed, thereby removing the excess salt from their system. Therefore, all of these mechanisms contribute to the survival of mangroves in salty conditions.
16.
The following diagram outlines the basic steps of the upward movement of water through the main parts (root, stem, and leaf) of a very tall conifer tree.Which of the following does label (X) in the diagram refer to?
Correct Answer
A. Osmosis
Explanation
The correct answer is osmosis. Osmosis is the process by which water moves from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane. In the context of the diagram, label (X) likely refers to the movement of water through the plant's cells via osmosis, as water moves from the roots to the stem and leaves.
17.
In the graph shown below, at which point the water concentration is greater outside the leaf?
Correct Answer
C. D
Explanation
In the given graph, point D represents the water concentration outside the leaf. This can be determined by observing that point D is located above the line representing the water concentration inside the leaf. Since water concentration always moves from an area of higher concentration to an area of lower concentration, point D indicates that the water concentration is greater outside the leaf.
18.
What is guttation?
Correct Answer
A. Exudation of xylem sap
Explanation
Guttation refers to the process of exudation of xylem sap from the leaves of plants. This usually occurs during the night when the plant's stomata are closed, and excess water pressure builds up in the xylem vessels. As a result, the sap is forced out through specialized structures called hydathodes, which are found at the tips or edges of leaves. Guttation is different from transpiration, as it involves the release of liquid instead of water vapor.
19.
What happens to the process shown in the figure below if the plant is put in a low-pressure area?
Correct Answer
A. Increases
Explanation
If the plant is put in a low-pressure area, the process shown in the figure will increase. This is because in a low-pressure area, the pressure surrounding the plant is lower than the pressure inside the plant. As a result, the plant will take in more water and nutrients from the soil through its roots, and this increased uptake will lead to an overall increase in the process.
20.
Which of the following plants has the highest transpiration rate?
Correct Answer
C. Bean
Explanation
Bean plants have a higher transpiration rate compared to the other plants listed because they have more stomata on their leaves, which allows for more water to evaporate. Additionally, bean plants typically have a larger leaf surface area, further increasing their transpiration rate.
21.
Which statements are correct regarding the excretion of CO2 in plant root cells?
A. CO2 remains inside the plant, gets dissolved in the xylem sap, and is then transported towards the apex.
B. CO2 diffuses out through the stomata of the root.
C. CO2 is utilized by the root cells in photosynthesis process.
D. CO2 reacts with water forming carbonic acid H2CO3 which is ionized into H+ and HCO3- where the H+ is used in soil’s cation exchange.
Correct Answer
D. A and D
Explanation
CO2 remains inside the plant, gets dissolved in the xylem sap, and is then transported towards the apex. This is because CO2 is produced in the root cells through respiration and needs to be transported to the leaves for photosynthesis. CO2 reacts with water forming carbonic acid H2CO3 which is ionized into H+ and HCO3-. The H+ ions are used in the soil's cation exchange, which helps in the absorption of nutrients by the roots.
22.
The graph below shows the results of an experiment that measures the amount of lost water from a plant during a day in the first week of April. What are the processes (A) and (B) respectively?
Correct Answer
B. Transpiration – Guttation
Explanation
The correct answer is Transpiration – Guttation. The graph shows a gradual increase in water loss from the plant during the first few days of April, which is characteristic of transpiration. However, on the last day of the graph, there is a sudden spike in water loss, indicating guttation. Guttation is the process by which water is excreted from the plant through specialized structures called hydathodes. Therefore, the correct processes represented by (A) and (B) on the graph are transpiration and guttation, respectively.
23.
Opening and closing of pores is a function performed by.......
Correct Answer
D. Guard cells
Explanation
Guard cells are responsible for the opening and closing of pores, known as stomata, in plants. Stomata are essential for gas exchange, allowing plants to take in carbon dioxide for photosynthesis and release oxygen and water vapor. Guard cells control the opening and closing of stomata by changing their shape. When the guard cells are turgid, the stomata open, allowing gas exchange. Conversely, when the guard cells lose water and become flaccid, the stomata close, preventing excessive water loss. Therefore, the correct answer is guard cells.
24.
Guttation is mainly due to.....
Correct Answer
A. Root pressure
Explanation
Guttation is the process by which water droplets are released from the tips of leaves. It occurs when root pressure forces water up from the roots and into the plant's xylem vessels. This pressure is created by the active transport of mineral ions into the root cells, which increases the solute concentration and causes water to move in by osmosis. As a result, the excess water is forced out of the leaf tips through specialized structures called hydathodes. Therefore, guttation is mainly due to root pressure.
25.
In an experiment to measure the rate of transpiration, The figure below shows two flasks (A) and (B) containing two similar leafy branches their ends are submerged in water. If flask (A) is kept in an area of high atmospheric pressure while flask (B) is kept in an area of low atmospheric pressure. What will happen to the amount of water in each flask after few hours of the experiment?
Correct Answer
A. Water amount in (B) will be less than in (A)
Explanation
In an experiment to measure the rate of transpiration, the two flasks (A) and (B) contain similar leafy branches submerged in water. Flask (A) is in an area of high atmospheric pressure, while flask (B) is in an area of low atmospheric pressure. Transpiration is the process by which water is lost from the leaves of plants through evaporation. In this experiment, the difference in atmospheric pressure between the two flasks will affect the rate of transpiration. Higher atmospheric pressure in flask (A) will result in less water being lost through transpiration compared to flask (B) with lower atmospheric pressure. Therefore, the water amount in flask (B) will be less than in flask (A) after a few hours of the experiment.
26.
Which of the following is(are) not among the excretory substances of the plant?
Correct Answer
D. Amino acids
Explanation
Amino acids are not excretory substances of plants because they are essential building blocks for proteins and are used in various metabolic processes. Plants do not excrete amino acids, but rather utilize them for growth and development. Water, carbon dioxide, and oxygen, on the other hand, are excretory substances in plants. Water is excreted through transpiration, carbon dioxide is released during respiration, and oxygen is released as a byproduct of photosynthesis.
27.
Name the specialized pores from where guttation takes place.
Correct Answer
B. Hydathodes
Explanation
Hydathodes are specialized pores found in the leaves of plants, particularly in the margins or tips of leaves. They are responsible for guttation, which is the process of exuding water droplets from the leaf surface. Unlike stomata, which primarily regulate gas exchange, hydathodes specifically release excess water from the plant. Guard cells are responsible for opening and closing stomata, while lenticels are small openings in the bark of woody plants for gas exchange. Therefore, the correct answer is hydathodes.
28.
Which of the following processes helps the plant to get rid of excess phosphate ions?
Correct Answer
D. Guttation
Explanation
Guttation is the process by which plants excrete excess water and dissolved substances, including phosphate ions, through specialized structures called hydathodes. These hydathodes are found at the tips or edges of leaves and allow the plant to release excess water and ions through droplets. Therefore, guttation helps the plant to get rid of excess phosphate ions.
29.
Which of the following conditions is not necessary for stomata opening?
Correct Answer
B. Humidity of the air surrounding the plant rises.
Explanation
An increase in the movement of air around a plant, falling carbon dioxide concentrations in the plant cells, and air temperatures of 36 °C are all conditions that are necessary for stomata opening. However, the humidity of the air surrounding the plant rising is not necessary for stomata opening. Stomata open in response to a decrease in water potential in the guard cells, which is caused by factors such as light, temperature, and carbon dioxide concentration. Humidity does not directly affect the water potential of the guard cells, so it is not necessary for stomata opening.
30.
Which of the following statement is INCORRECT for transpiration?
Correct Answer
A. Root pressure is involved
Explanation
Transpiration is the process by which water is lost from a plant through the stomata, lenticels, and cuticle in the form of water vapor. Root pressure, on the other hand, is involved in the process of guttation, which is the exudation of water droplets from the tips of leaves or other plant structures. Therefore, the statement "Root pressure is involved" is incorrect for transpiration.
31.
Both transpiration and guttation are affected by the change of the season. But they differ from each other in the nature and the amount of water loss.
Correct Answer
A. The two statements are correct.
Explanation
Both transpiration and guttation are affected by the change of the season. Transpiration is the process by which plants lose water through their leaves, and it is influenced by factors such as temperature, humidity, and wind. The change of the season can affect these factors and therefore impact the rate of transpiration. Guttation, on the other hand, is the process by which plants release liquid water from specialized structures called hydathodes. This process is also influenced by environmental factors and can be affected by the change of the season. Therefore, both transpiration and guttation are indeed affected by the change of the season, but they differ in the nature and amount of water loss.
32.
How does the plant encounter the hot environmental conditions?
Correct Answer
B. Increasing transpiration process
Explanation
When plants encounter hot environmental conditions, they increase their transpiration process. Transpiration is the process by which water is lost from the plant through the stomata in the leaves. This helps to cool the plant down as the water evaporates from the leaves. By increasing transpiration, the plant is able to release excess heat and maintain its temperature within a suitable range for survival. Decreasing photosynthesis process, decreasing water absorption, and increasing water reabsorption would not directly help the plant to cope with hot environmental conditions.
33.
If you want to study the mechanism by which plants undergo transpiration, which of the following would you examine?
Correct Answer
D. Stomata, rate of water absorption, and atmospHeric temperature
Explanation
To study the mechanism of transpiration in plants, one would need to examine the stomata, rate of water absorption, and atmospheric temperature. Stomata are small openings on the surface of leaves that regulate the exchange of gases and water vapor. The rate of water absorption refers to the uptake of water by the roots and its movement through the plant. Atmospheric temperature plays a crucial role in transpiration as it affects the rate of evaporation of water from the leaves. Therefore, by examining these factors together, one can gain a comprehensive understanding of the transpiration process in plants.
34.
What is the result of planting Tomato plant in a high moisture soil?
Correct Answer
B. Increasing of transpiration rate
Explanation
When a tomato plant is planted in a high moisture soil, it will increase its transpiration rate. Transpiration is the process by which plants lose water through their leaves. In high moisture soil, there is an abundance of water available for the plant to absorb through its roots. This excess water causes the plant to increase its transpiration rate in order to maintain a balance of water and nutrients within its cells. Therefore, the correct answer is increasing of transpiration rate.
35.
If you know that Elodea plant is an aquatic one lives in fresh water. Which of the following contradicts excretion of the plant?
Correct Answer
B. The plant reuses the O2 results from pHotosynthesis
Explanation
The Elodea plant, being an aquatic plant, lives in fresh water and therefore does not need to excrete excess water or waste products like terrestrial plants do. The plant reuses the CO2 produced from respiration and stores organic salts and acids in its cells. However, it cannot reuse the O2 produced from photosynthesis because it is a byproduct of the plant's metabolic processes and is released into the surrounding water.
36.
Which graph represents the proper relationship between the rate of transpiration and one of its internal factors?
Correct Answer
A. A
37.
What is the factor that causes the exit of CO2 from plant leaves stomata?
Correct Answer
A. Increasing its diffusion rate through a network of air spaces within the plant
Explanation
Increasing the diffusion rate of CO2 through a network of air spaces within the plant is the factor that causes the exit of CO2 from plant leaves stomata. The network of air spaces within the plant allows for increased surface area for gas exchange, facilitating the diffusion of CO2 out of the leaf. This process is essential for plants to obtain the necessary carbon dioxide for photosynthesis and to release the byproduct, oxygen, into the atmosphere.
38.
One of the following statements describes guttation .....
Correct Answer
D. When a plant pushes excess water out
Explanation
Guttation is a process in which plants release excess water through specialized structures called hydathodes. This typically occurs when the soil is moist and the plant's roots absorb more water than it needs for photosynthesis and other metabolic processes. The excess water is forced out of the plant through hydathodes located on the edges of leaves or tips of grass blades. This process helps maintain the water balance within the plant and prevents the accumulation of too much water, which can be detrimental to its growth and survival.
39.
Transpiration in plants is closely similar to in humans ----------.
Correct Answer
D. Sweating
Explanation
Transpiration in plants is closely similar to sweating in humans. Both processes involve the loss of water from the organism. In plants, transpiration occurs through the stomata on the leaves, where water evaporates and is released into the atmosphere. Similarly, in humans, sweating occurs through the sweat glands in the skin, where water evaporates and helps regulate body temperature. Both transpiration and sweating are important mechanisms for maintaining water balance and temperature regulation in plants and humans, respectively.
40.
The following table illustrates the rate of transpiration for four plants. Which of them describes proper readings for the rate of transpiration under the different environmental conditions shown in the table?
Correct Answer
A. A
Explanation
Without the table or any information about the environmental conditions and the rate of transpiration for each plant, it is impossible to provide an explanation for why option A is the correct answer.
41.
Which of the following doesn’t exit out through stomata?
Correct Answer
D. Mineral salts
Explanation
Mineral salts do not exit out through stomata. Stomata are small openings on the surface of leaves that allow for the exchange of gases, such as oxygen and carbon dioxide, as well as the release of water vapor during transpiration. However, mineral salts are absorbed by the roots of plants and transported through the xylem to the rest of the plant for various physiological functions, such as nutrient uptake and growth. Therefore, mineral salts do not exit through stomata.
42.
Water is lost in a liquid state in some plants through hydathodes. These hydathodes .....
Correct Answer
C. Remain always open
Explanation
Hydathodes are specialized structures in plants that allow water to be lost in a liquid state. Unlike stomata, which open and close to regulate gas exchange, hydathodes remain always open. This continuous opening of hydathodes allows for the release of excess water from the plant, a process known as guttation. This helps to maintain the water balance in the plant and prevent damage from excess water accumulation. Therefore, the correct answer is that hydathodes remain always open.
43.
From the factors which oppose transpiration in plants ……
Correct Answer
A. Thicker cuticle layer
Explanation
A thicker cuticle layer on the surface of the leaf would reduce the rate of transpiration in plants. The cuticle is a waxy layer that covers the epidermis of the leaf and acts as a barrier to water loss. By having a thicker cuticle, less water would be able to evaporate from the leaf surface, thus reducing the overall rate of transpiration.
44.
During the ascent of sap, the water column present inside vessels and tracheids, does not rupture due to .....
Correct Answer
C. Cohension and adhesion
Explanation
The water column inside vessels and tracheids does not rupture during the ascent of sap due to cohesion and adhesion. Cohesion refers to the attraction between water molecules, causing them to stick together, while adhesion refers to the attraction between water molecules and the walls of the vessels and tracheids. These forces of cohesion and adhesion help to maintain the integrity of the water column and prevent it from breaking apart as water is pulled up through the plant.
45.
Plant seedlings were put in four tubes; each contains 200 C.C water, for two days under same environmental conditions as shown in figure below. Which seedling its leaves were covered with paraffin wax?
Correct Answer
A. A
Explanation
Based on the information provided, the seedling with its leaves covered in paraffin wax is seedling A.
46.
The following figure is for an experiment to measure the rate of transpiration in two branches of a certain plant. Which reading of the spring balance is the correct one after three days of the experiment?
Correct Answer
C. C
47.
Which of the following will not directly affect transpiration?
Correct Answer
B. ChloropHyll content of leaves
Explanation
The chlorophyll content of leaves will not directly affect transpiration because transpiration is the process by which water evaporates from the surface of plant leaves. It is primarily influenced by factors such as temperature, wind speed, and atmospheric pressure. The chlorophyll content of leaves, on the other hand, is responsible for capturing sunlight and aiding in photosynthesis, but it does not directly impact the evaporation of water from the leaves.
48.
Assuming that transpiration in a plant has stopped, which of the following statements would be correct in this case?
Correct Answer
B. The supply of water to plant parts would stop, especially the higher ones.
Explanation
Transpiration is the process by which water is lost from a plant through its leaves. If transpiration stops, the supply of water to plant parts would stop, especially the higher ones. This is because transpiration creates a suction force that pulls water up through the plant's vascular system. Without transpiration, this suction force would not be present, and water would not be able to reach the higher parts of the plant. Therefore, the correct statement in this case would be that the supply of water to plant parts would stop, especially the higher ones.
49.
Due to low atmospheric pressure, the rate of transpiration will ….
Correct Answer
A. Increase
Explanation
Low atmospheric pressure means that there is less pressure pushing down on the surface of the leaves, which allows for an easier escape of water vapor through the stomata. As a result, the rate of transpiration increases.
50.
Which condition favors "Guttation" ?
Correct Answer
A. High humidity.
Explanation
Guttation is the process by which plants release excess water droplets through specialized structures called hydathodes. High humidity creates a moist environment around the plant, reducing the rate of evaporation and allowing water to accumulate in the plant tissues. This accumulation of water eventually leads to guttation. Therefore, high humidity favors the occurrence of guttation.