Test: Getting to Know About Plants - Class 6 MCQ

There are some plants with weak stems that cannot stand upright and spread on the ground. These are called creepers, while those that take support on neighbouring structures and climb up are called climbers. These are different from the herbs, shrubs and trees.

Parts of the Stem

All stems of the angiosperms, including those which are highly modified, are recognizable from other plant organs by their presence of nodes, internodes, buds and leaves. A node is a point on the stem from which leaves or buds arise. The portion between two successive nodes is the internode.

A bud is an embryonic stem which has the potential for further plant growth. It may develop into a leaf, flower, or both. Such buds are called leaf buds, flower buds and mixed buds, respectively. Many buds remain dormant within a certain duration or they may be embedded in the stem tissue as to become hardly visible. A single bud that is found at the apex of the stem is called terminal bud while lateral buds or axillary buds occur in the leaf axils, the upper angle between the stem and leaves. As a result of injury, adventitious buds may be formed also in the internode of the stems, in leaves, or roots. The “eyes” of the potato tuber are buds.

• Flowers: They hold the plant's baby-making parts and aid in pollination, where pollen reaches the eggs for fertilization.
• Fruits: They come from a flower's ripe ovary, housing seeds. Fruits help seeds spread for new plant growth.
• Seeds: These are baby plants' beginnings with all the genetic details for future growth. They often travel with the help of wind, animals, or water.
• In contrast, roots, stems, and leaves are about plant support, growth, and food-making through photosynthesis.

The male sex cells of seed plants (flowering plants, conifers, and cycads) are contained in tough capsules called POLLEN. Pollen grains are produced by organs called anthers and must be transferred to the female parts of plants in order to form seeds. This process, called pollination, can be achieved in various ways. Some plants are assisted by animals that act as POLLINATORS. 

Embryo or baby plant: It is present inside the seeds which develop into a new plant. The embryo gives rise to a baby shoot (plumule) and root (radical).

Plants with green and tender stems are called herbs. They are usually short and may not have many branches.

Onion is one among the family of plants,with modified stem. The onion bulb is the modified stem,which is used for eating. If the plant as a whole is observed then one can find roots at the lower end while leaves can be seen on the other end,in green onions.

Cuscuta possess no roots nor fully expanded leaves and the vegetative portion appears to be a stem only.

The major function of stomata is the exchange of gases by taking carbon dioxide from the atmosphere and giving out oxygen that is used by human beings and animals.  They help in photosynthesis and transpiration.

Photosynthesis

Photosynthesis is a process used by plants to manufacture food with the help of sunlight, carbon dioxide and water. It is through the stomata that the plant takes carbon dioxide from the atmosphere. The water molecule is broken down into hydrogen and oxygen, and it is through the stomata that the oxygen is then released as a by-product in the atmosphere. Stomata are the medium of gaseous exchange and cellular respiration in plants.

Transpiration

Transpiration is a process of evaporation of water from the surface of the plant. This keeps the plant cool and transfers minerals and other materials to different parts of the plant. As the plant takes water from the soil, the openings absorb other minerals. For a plant to take water from the soil, water needs to evaporate from the surface of the plant. Once this happens, pressure is developed that forces the roots to absorb water from the soil and transfer it to the tips of the plant. It is through the stomata that the major work of evaporation of water is done.

The male sex cells of the seed plants or flowering plants are contained in tough capsules, called as pollen. Pollen grains are produced by male organs, anthers or stamens.

Thus, the correct answer is option (A), 'Anther'.