Biology Experiments: Stomata and Gas Exchange

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Questions and Answers

Explain the role of KOH pellets in Experiment No. 2 and why the water level in the bent tube rises.

KOH pellets absorb carbon dioxide (CO2) released during the respiration of the germinating seeds. This reduction in CO2 concentration in the flask creates a partial vacuum, causing the water level in the bent tube to rise.

Describe the chemical equation for respiration and explain the significance of this process for living organisms.

The chemical equation for respiration is: $C_6H_{12}O_6 + 6O_2 \longrightarrow 6CO_2 + 6H_2O + Energy$. This process is vital for living organisms because it breaks down glucose to release energy (ATP) needed for various life functions, like growth, movement, and repair.

What are the two main types of respiration and what differentiates them?

The two main types of respiration are aerobic and anaerobic respiration. Aerobic respiration requires oxygen for complete oxidation of substrates, producing CO2 and water, while anaerobic respiration doesn't use oxygen, leading to incomplete oxidation and producing CO2 and ethanol (or other products).

Why is it necessary to soak the gram seeds overnight and germinate them before starting Experiment No. 2?

Soaking the seeds overnight and allowing them to germinate ensures that they are actively respiring, producing a sufficient amount of CO2 to be observed in the experiment. Signup and view all the answers

What safety precautions should be taken during Experiment No. 2 and why?

KOH is corrosive, so it should be handled with care. Connections should be made airtight with molten wax to prevent leaks and ensure accurate observation of CO2 absorption. Signup and view all the answers

Explain the process of binary fission and its relevance to single-celled organisms.

Binary fission is a method of asexual reproduction in which a single-celled organism splits into two identical daughter cells. It's a rapid and efficient way for single-celled organisms to reproduce and increase their population. Signup and view all the answers

In Experiment No. 3, how does the use of prepared slides contribute to the study of binary fission or budding?

Prepared slides provide ready-made samples of organisms undergoing binary fission or budding, allowing for detailed observation of these processes under the microscope. Signup and view all the answers

How is the study of binary fission and budding important in understanding the diversity of life?

These processes demonstrate the different ways in which organisms reproduce and contribute to the evolution of new species. They highlight the diversity of reproductive strategies in living organisms. Signup and view all the answers

What is the function of the cotyledons in a bean seed?

The cotyledons serve as food storage organs for the developing embryo and also act as the first leaves of the seedling. Signup and view all the answers

Explain the difference between the epicotyl and the hypocotyl in a germinating seed.

The epicotyl is the part of the embryonal axis above the cotyledons, which will develop into the shoot, while the hypocotyl is the part below the cotyledons that will form the root. Signup and view all the answers

Why is it important to ensure that the embryonal axis remains intact when separating the cotyledons?

The embryonal axis contains the plumule and radicle, which are essential for the development of the shoot and root, respectively. Damage to the embryonal axis will prevent proper germination. Signup and view all the answers

What are the three main factors that need to be optimized for successful seed germination?

The three main factors are warmth, moisture, and air. These factors create an environment conducive to the activation of the seed's metabolic processes and subsequent emergence of the seedling. Signup and view all the answers

Describe the role of the micropyle in seed germination.

The micropyle is an opening in the seed coat that allows water to enter the seed, initiating the germination process. Signup and view all the answers

What are stomata and what role do they play in a plant?

Stomata are structures on leaves that facilitate gaseous exchange, allowing plants to take in carbon dioxide and release oxygen. They are bordered by guard cells that regulate their opening and closing. Signup and view all the answers

Describe the difference in stomatal behavior when exposed to light versus darkness.

In light, stomata open as guard cells become turgid, allowing gas exchange, while in darkness, they close as guard cells lose turgidity and become flaccid. Signup and view all the answers

What types of stomatal distribution can be observed in dicot and monocot leaves?

Dicots typically exhibit hypostomatous stomatal distribution (only on lower surface), while monocots show amphistomatous distribution (on both surfaces, more on the lower side). Signup and view all the answers

Why is it important to select a turgid leaf for observation during the experiment?

A turgid leaf is essential because it ensures that the stomata are open and available for observation, providing accurate results regarding their structure and function. Signup and view all the answers

Explain the procedure for preparing a temporary mount of a leaf peel.

To prepare a temporary mount, take a turgid leaf, gently peel the lower epidermis, place it on a glass slide with a drop of glycerin, and cover it with a coverslip for microscopic examination. Signup and view all the answers

What precautions should be taken when mounting a leaf peel for observation?

Precautions include selecting a turgid leaf, carefully removing the peel from the lower epidermis, ensuring the outer surface is facing the objective lens, and keeping the peel wet. Signup and view all the answers

What observations can be made about the structure of stomata in a dicot leaf after exposure to sunlight?

In a dicot leaf exposed to sunlight, stomata appear open, revealing oblong or oval pores surrounded by kidney-shaped guard cells. Signup and view all the answers

What is the significance of guard cells in the functioning of stomata?

Guard cells are significant because they control the opening and closing of stomata, thus regulating gas exchange and water loss in plants. Signup and view all the answers

What are daughter cells in the context of binary fission in Amoeba?

Daughter cells are the two new equal-sized cells formed when the parent cell divides during binary fission. Signup and view all the answers

Describe the first observation that occurs during the binary fission of Amoeba.

The parent cell becomes elongated as the nuclear body duplicates and prepares to split. Signup and view all the answers

How does budding in yeast differ from binary fission in Amoeba?

Budding in yeast involves the growth of a small protuberance on the parent cell, whereas binary fission consists of the parent cell splitting directly into two daughter cells. Signup and view all the answers

What role do cotyledons play in dicot seeds?

Cotyledons store food and are attached to the embryonal axis at the node. Signup and view all the answers

What are the key parts of an embryo in dicot seeds?

The key parts include the radicle (root apex), epicotyl with plumule (shoot apex), and cotyledons. Signup and view all the answers

What should a student do before observing slides under high power with a microscope?

The student should first focus the slide under low power to get a clear view. Signup and view all the answers

What is the significance of seed germination in plants?

Seed germination marks the resumption of growth and development after a period of dormancy. Signup and view all the answers

What observation can be made during budding in Hydra?

A distinct outgrowth is formed on the body of Hydra, which can develop into a new individual. Signup and view all the answers

Flashcards

What is respiration?

Respiration is the process where living cells break down organic compounds like glucose to release energy, usually in the form of ATP.

What is Aerobic Respiration?

Aerobic respiration uses oxygen to completely break down glucose, producing carbon dioxide and water as byproducts.

What is Anaerobic Respiration?

Anaerobic respiration does not use oxygen and breaks down glucose partially, producing carbon dioxide and other byproducts like alcohol.

What is binary fission?

Binary fission is a type of asexual reproduction where a single parent cell splits into two identical daughter cells.