Forms and functions in plants Short questions chapter 10

Question 1: Why mineral nutrients are necessary for plants?

Without proper amounts of these nutrients, plants may exhibit stunted growth, yellowing of leaves, and reduced yield or even death in extreme cases.

Question 2: Why N2 is included in mineral nutrient although it not mineral?

N2 or atmospheric nitrogen is not technically a mineral nutrient as it is not derived from the soil. However, it is still considered an essential nutrient for plant growth because plants require nitrogen to synthesize proteins and other essential biomolecules.

Although nitrogen makes up 78% of the atmosphere, it is in a form that is not readily usable by most plants. Nitrogen fixation is the process by which atmospheric nitrogen is converted into a usable form, such as ammonium (NH4+) or nitrate (NO3-), by certain bacteria that live in the soil or in symbiosis with plants.

Plants take up nitrogen in the form of these nitrogenous compounds and use it for various purposes, such as building proteins and nucleic acids, and as a source of energy. Therefore, even though nitrogen is not technically a mineral nutrient, it is included in the list of essential mineral nutrients for plants because it is necessary for their growth and development

Questions 3: Why desert plants reduce their leaves size?

Desert plants have evolved various adaptations to survive in their harsh and arid environment, and reducing leaf size is one of them. There are several reasons why desert plants may reduce their leaf size:

Minimizing water loss: In a desert environment, water is scarce and conserving water is essential for survival. Leaves are one of the primary sites of water loss through transpiration, where water is lost through small openings called stomata. By reducing leaf size, desert plants can reduce the surface area for transpiration and conserve water.

Overall, reducing leaf size is a common adaptation of desert plants that helps them to conserve water, avoid heat stress, increase nutrient uptake, and avoid herbivory

Question 4 : Why carnivore plants use insects as food?

Carnivorous plants have evolved to use insects and other small animals as a source of nutrients, especially in environments where the soil lacks essential nutrients like nitrogen and phosphorus. In these environments, carnivorous plants have developed specialized structures to trap and digest prey, such as sticky leaves, pitchers, or snap traps.

Overall, carnivorous plants have adapted to their nutrient-poor habitats by developing specialized structures to capture and digest insects and other small animals. By using insects as food, these plants are able to obtain the nutrients they need to survive and reproduce, and avoid competition with other plants for limited soil resources.

Question 5: Why phytochrome pigments are important to photoperiodism?

Phytochrome pigments are important to photoperiodism because they are the photoreceptors that plants use to sense changes in day length. These pigments are able to detect changes in the duration of light and dark periods, which allows plants to adjust their growth and development in response to seasonal changes in their environment. Specifically, the phytochrome system allows plants to distinguish between short days and long days, and to trigger different responses accordingly, such as flowering, dormancy, or leaf senescence.

Question 6: How annual rings are formed?

Annual rings are formed in trees as a result of seasonal variations in growth. During the growing season, new cells are produced in the cambium layer, which form the earlywood. As the season ends, smaller, thicker-walled cells are produced, forming the latewood. The distinct differences in cell size and density between the earlywood and latewood create the visible rings, with each ring representing one year of growth.

Question 7: Why cold treatment is necessary for germination of seeds in some plants?

Cold treatment, also known as stratification, is necessary for germination of seeds in some plants because it helps to break seed dormancy and initiate the process of germination. Many plants, particularly those native to cold climates, have evolved to require a period of cold temperature in order to germinate.

Cold treatment works by mimicking the natural conditions that the seeds would experience if they were left to overwinter in the ground. During this period, the seeds are exposed to a prolonged period of cold and moist conditions, which stimulates the production of gibberellins, a hormone that promotes germination.

Without this period of cold treatment, many seeds would remain dormant and fail to germinate, even under ideal growing conditions. By subjecting the seeds to a period of cold treatment, gardeners and farmers can improve their chances of successful germination and establishment of the plants.

Question 8: How osmotic adjustment is beneficial for plants?

Osmotic adjustment is beneficial for plants because it allows them to adapt to changes in soil moisture and salinity, and maintain their cellular turgor pressure and growth even under adverse conditions. Osmotic adjustment is a physiological process by which plants regulate the concentration of solutes in their cells to counterbalance the osmotic potential of the soil solution.

When soil moisture is limited or soil salinity is high, water moves out of the plant cells, causing a decrease in their turgor pressure and inhibiting plant growth. Osmotic adjustment enables plants to maintain their cellular water balance and turgor pressure by actively accumulating solutes such as sugars, amino acids, and ions in their cells.

By doing so, plants can reduce their water potential and increase their resistance to drought, salinity, and other environmental stresses. This adaptation strategy allows plants to grow and survive in a wider range of habitats and conditions, making them more resilient to environmental changes and increasing their chances of survival and reproduction.