Question

1. Функції листка а) Газообмiн в) Дихання 00 2. 3. 4. 5. 6. 7. 8. 9. Випаровування води листком це- а) Дихання в) Транспірація Паралельне жилкування мають листки таких рослин а) Пшениця в) Овес Листок прикріплюється до стебла у а) Пазусі в) Камбії Жилки забезпечують у листках a) Mexahiчний захист в) фотосинтез Вусики гороху - це видозмінені а) Пагони в) Корені Шавлія, бузок, глуха кропива мають листкорозміщення a) Супротивне в) Мутовчасте Назвіть рослину із складним листком а) Елодея в) Верба 10. за формою пластинки розрізняють листки а) Сидячі в) Елiптичні д) Лінійні 00 б) Транспірація г) всмоктування 000 б) фотосинтез г) Газообмін Існують такі типи жилкування листків (виберіть кілька варіантів) а) Паралельне в) Сітчасте б) Береза г) Тонконіг б) Міжвузлi г) Вузлi б) Транспорт речовин г) Запас речовин б) Листки г) Стебла б) кiльцеве г) Дугове б) кiльчасте г) Почергове б) Суниця г) Вишня б) Овальнi г) Округлі e) Черешкові 11. На якій поверхні листків у латаття, калачиків та пшениці містяться продихи а) Нижній б) обох г) Верхній в) жодній 12. Виберіть правильний варіант розмiщення тканин у внутрішній будовİ листка починаючи з верхньої шкірки: 1. Губчаста паренхіма; 2. ксилема; 3. Стовпчаста паренхіма; 4. Флоема; 5.Склеринхіма і коленхіма; 6. Нижня шкірка. а) 3,1,5,2,4,6 B) 1,2,3,4,5,6 6) 3,2,4,5,1,6 r) 1,2,4,3,5,6

Answer 1

Ответ:

3,1,5,2,4,6

B) 1,2,3,4,5,6

6) 3,2,4,5,1,6ир

r) 1,2,4,3,5,6

Answer 2

Functions of Leaves:

Leaves perform several important functions in plants, including gas exchange, respiration, transpiration, and photosynthesis. They also play a role in the storage of substances and provide structural support to the plant. Let's explore each of these functions in more detail.

Gas Exchange:

Leaves are responsible for the exchange of gases, such as oxygen and carbon dioxide, with the atmosphere. This process is essential for photosynthesis and respiration. During photosynthesis, leaves take in carbon dioxide and release oxygen, while during respiration, they take in oxygen and release carbon dioxide. [[1]].

Respiration:

Leaves are involved in the process of respiration, which is the release of energy from organic compounds. This energy is used by the plant for various metabolic activities. Respiration takes place in the cells of the leaves, where oxygen is consumed and carbon dioxide is produced. [[2]].

Transpiration:

Transpiration is the process by which water is lost from the leaves of plants in the form of water vapor. It occurs through small openings called stomata, which are primarily located on the undersides of leaves. Transpiration helps in the absorption and transport of water and minerals from the roots to the rest of the plant. [[3]].

Photosynthesis:

One of the most important functions of leaves is photosynthesis. In this process, leaves use sunlight, carbon dioxide, and water to produce glucose (a type of sugar) and oxygen. Chlorophyll, a pigment found in chloroplasts within leaf cells, captures sunlight and converts it into chemical energy, which is then used to drive the synthesis of glucose. This glucose serves as a source of energy for the plant and is also used for growth and other metabolic processes. [[4]].

Leaf Structure and Adaptations:

Leaves exhibit various adaptations and structural features that enable them to carry out their functions effectively. Some of these adaptations include:

- Parallel Veination: Some plants, such as grasses like wheat and oats, have leaves with parallel veins. This arrangement allows for efficient transport of water and nutrients throughout the leaf. [[5]]. - Leaf Attachment: Leaves can be attached to the stem in different ways. For example, some leaves have axillary buds that attach them to the stem at the nodes, while others are attached by petioles or leaf stalks. [[6]]. - Leaf Venation: The veins in leaves play a crucial role in transporting water, nutrients, and sugars. They also provide structural support to the leaf. Different plants exhibit different types of venation, such as reticulate (net-like), parallel, or palmate (radiating from a central point). [[7]]. - Leaf Modifications: Some plants have modified leaves that serve specific functions. For example, tendrils in pea plants and leaflets in sensitive plants help in climbing and capturing support structures. [[8]].

Leaf Arrangement:

The arrangement of leaves on a plant can vary. Some common leaf arrangements include:

- Opposite: Leaves are arranged in pairs opposite each other on the stem. - Alternate: Leaves are arranged singly at different points along the stem. - Whorled: Leaves are arranged in a circular pattern around the stem.

Different plants may have different leaf arrangements, and these arrangements can provide insights into the plant's growth and development. [[9]].

Leaf Shapes:

Leaves come in various shapes, and the shape of a leaf can provide information about the plant species. Some common leaf shapes include:

- Oval: Leaves that are elongated and rounded at both ends. - Linear: Leaves that are long and narrow with parallel sides. - Elliptical: Leaves that are elongated and widest in the middle. - Circular: Leaves that are round in shape. - Heart-shaped: Leaves that resemble the shape of a heart. - Lobed: Leaves that have deep indentations or lobes.

Leaf shape can vary greatly among different plant species and can be used as a characteristic for plant identification. [[10]].

Leaf Tissues:

The internal structure of a leaf consists of different types of tissues that perform specific functions. These tissues include:

- Upper Epidermis: The uppermost layer of cells that protects the leaf and prevents excessive water loss. - Palisade Mesophyll: A layer of elongated cells containing chloroplasts, responsible for most of the photosynthesis. - Spongy Mesophyll: A layer of loosely arranged cells that facilitate gas exchange and contain chloroplasts. - Lower Epidermis: The lowermost layer of cells that contains stomata for gas exchange and guard cells that regulate their opening and closing. - Vascular Tissues: Xylem and phloem tissues that transport water, nutrients, and sugars throughout the leaf and the rest of the plant. - Bundle Sheath Cells: Cells that surround the vascular tissues and provide support and protection.

The arrangement and organization of these tissues within the leaf contribute to its overall function and efficiency. [[11]].

Leaf Surface and Stomata:

Stomata are small openings found on the surface of leaves that allow for gas exchange and transpiration. The majority of stomata are located on the lower surface of leaves, although some plants may have stomata on both surfaces. The distribution of stomata can vary depending on the plant species and environmental conditions. [[12]].

Leaf Vein Arrangement:

The arrangement of veins within a leaf can also vary. Some common vein arrangements include:

- Parallel: Veins run parallel to each other from the base to the tip of the leaf, as seen in grasses like wheat. - Netted/Reticulate: Veins form a network-like pattern throughout the leaf, as seen in most dicot plants. - Palmate: Veins radiate from a central point, resembling the fingers of a hand, as seen in maple leaves.

The vein arrangement in leaves helps in the transport of water, nutrients, and sugars, as well as providing structural support. [[13]].

Leaf Tissue Organization:

The tissues within a leaf are organized in a specific manner. The correct arrangement of tissues, starting from the upper epidermis, is as follows:

1. Upper Epidermis 2. Palisade Mesophyll 3. Spongy Mesophyll 4. Lower Epidermis 5. Bundle Sheath Cells

This organization allows for efficient gas exchange, photosynthesis, and structural support within the leaf. [[14]].

In conclusion, leaves are vital organs of plants that perform various functions, including gas exchange, respiration, transpiration, and photosynthesis. They exhibit different adaptations, shapes, arrangements, and tissue organizations to carry out these functions effectively.