Morphology of Plants MCQ Quiz in मल्याळम - Objective Question with Answer for Morphology of Plants - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

Concept:

• The root is a vegetative part of the plant that performs different functions.
• The primary roles of the root system are to absorb water and minerals from the soil, provide anchorage, the storage of food reserves, and the production of plant growth regulators.

Explanation:

• The root cap, which resembles a thimble, protects the root at its tip.
• As the root travels into the earth, it is shielded to preserve its delicate apex.
• The area of meristematic activity is located a few millimeters above the root cap.
• The cells in this area have thin walls, a tiny size, and a thick protoplasm. They separate again and again. The cells close to this area quickly increase and lengthen, which is what causes the root's expansion in length. It is known as the zone of elongation.
• Cells of the elongation zone mature and differentiate throughout time. Therefore, this area, which is close to the region of elongation, is known as the maturation region.
• A tiny collection of cells with minimal mitotic activity is known as the quiescent center (QC) (they divide sometimes, but only rarely). In the root meristem, QCs are located at the terminals of developing roots and are frequently surrounded by clusters of initial cells.
• So, the quiescent center quiescent center has slow-dividing cells.

So, the correct answer is Option 1, slow-dividing cells.

Concept:

• Flowers are the reproductive organs in the angiosperms.
• The gynoecium is the female reproductive part in the flower while the androecium is the male reproductive organ.

Explanation:

• A flower with both male and female reproductive organs is called the bisexual flower.
• A flower with either stamen or carpel is called a unisexual flower.
• In addition to androecium, and gynoecium; flowers also have calyx (whorl of sepals), and corolla (whorl of petals).
• Classification of flowers (based on the position of calyx, corolla, and androecium with respect to the ovary on the thalamus) is given below:

So, the correct answer is option 3,  Inferior ovary.

Concept:

• The flower is the reproductive unit in the angiosperms. It is meant for sexual reproduction.
• A typical flower has four different kinds of whorls arranged successively on the swollen end of the stalk or pedicel, called the thalamus or receptacle.
• These are calyx, corolla, androecium and gynoecium. Calyx and corolla are accessory organs, while androecium and gynoecium are reproductive organs.

Explanation:

• Based on the position of calyx, corolla and androecium in respect of the ovary on the thalamus, the flowers are described as hypogynous, perigynous and epigynous.

Hypogynous flower:

• In the hypogynous flower, the gynoecium occupies the highest position while the other parts are situated below it. The ovary in such flowers is said to be superior, e.g., mustard, china rose and brinjal.

Thereby, the hypogynous flower has a superior ovary seated on the thalamus

Position of floral parts on thalamus : (a) Hypogynous, (b) and (c) Perigynous, (d) Epigynous

Additional Information

• Perigynous flower: If gynoecium is situated in the centre and other parts of the flower are located on the rim of the thalamus almost at the same level, it is called perigynous. The ovary here is said to be half inferior, e.g., plum rose, peach.
• Epigynous flower: In epigynous flowers, the margin of the thalamus grows upward enclosing the ovary completely and getting fused with it, the other parts of the flower arise above the ovary. Hence, the ovary is said to be inferior as in flowers of guava and cucumber, and the ray florets of sunflower.

The correct answer is Unicellular

Explanation:

• Trichomes are hair-like outgrowths of the epidermis in plants. They can be found on stems, leaves, and reproductive organs.
• These structures serve various functions such as protection against herbivores, reducing water loss, and sometimes aiding in seed dispersal.
• Trichomes are generally multicellular, consisting of multiple cells forming the hair-like structures. 
• Trichomes originate from the epidermal tissue system, which is the outermost layer of cells in plants. This tissue system plays a crucial role in protection and interaction with the environment.

When the floral appendages are in multiples of 5, the flower is termed as Pentamerous.

Explanation:

• Pentamerous flower:
  • Floral appendages are in multiples of 5.
  • This is a characteristic feature of dicotyledonous plants.
  • Examples include Rose, Hibiscus, and Apple.
• Trimerous flower:
  • Floral appendages are in multiples of 3.
  • Commonly seen in monocotyledonous plants.
  • Examples include Tulip, Lily, and Daffodil.
• Tetramerous flower:
  • Floral appendages are in multiples of 4.
  • This can also be seen in some dicotyledonous plants.
  • Examples include Mustard and Alyssum.
• Perigynous flower:
  • The floral parts are at the same level as the ovary and form a cup-like structure around it.
  • It refers to the position of the ovary rather than the arrangement of floral appendages.
  • Examples include Rose and Peach.

The correct answer is All of the above

Explanation:

• Mature seeds may be non-albuminous or ex-albuminous.
• Non-albuminous seeds have no residual endosperm as it is completely consumed during embryo development (e.g., pea, groundnut).
• Albuminous seeds retain a part of endosperm as it is not completely used up during embryo development (e.g., wheat, maize, barley, castor).
• Occasionally, in some seeds such as black pepper and beet, remnants of nucellus are also persistent. This residual, persistent nucellus is the perisperm.

Endospermic seeds are those that retain endosperm tissue as a food reserve for the developing embryo. Castor, maize, and wheat are all examples of plants that produce endospermic seeds, where the endosperm provides nourishment to the seedling during germination. Hence, the correct answer is "All of the above."

The correct answer is thalamus

Explanation

Epicarp: This is the outermost layer of the pericarp (fruit wall), commonly known as the skin or peel of the fruit. For example, in apples and pears, the epicarp is the outer skin that you see and touch.
Mesocarp: The mesocarp is the middle layer of the pericarp, usually the fleshy and often the most substantial part of the fruit. In some fruits like peaches and mangoes, the mesocarp is the juicy, edible portion.
Endocarp: This is the innermost layer of the pericarp, which directly surrounds the seed(s). It can be hard or stony in some fruits like peaches and cherries (forming the pit), or it can be more membranous as in apples and pears.
Thalamus: In the case of apples and pears, the thalamus is the part of the flower that develops into the fruit. These fruits are known as pome fruits, where the edible part is derived from the enlarged and fleshy thalamus. The true fruit part (which includes the pericarp: epicarp, mesocarp, and endocarp) is actually the central core that surrounds the seeds.

Concept:

• A flower is a modified shoot whose floral meristem has replaced the shoot's apical meristem.
• The axis condenses and internodes do not elongate.
• At succeeding nodes, the apex generates a variety of floral appendages in place of leaves.

Explanation:

The inflorescence may be of two types, which depends on whether the apex gets developed into a flower or continues to grow.

In Racemose type of inflorescences, the main axis continues to grow, the flowers are borne laterally in acropetal succession. In Acropetal succession, the youngest flower is present near the apex and older towards the base.

In Cymose type of inflorescence the main axis terminates in a flower, hence is limited in growth. The flowers are borne in a basipetal succession. In basipetal succession, the older flowers are present at the upper portion and young buds are arranged towards the base.

So, the correct answer is option 3, Growth is limited and the flowers are bore in basipetal succession.

Concept:

• The mode of arrangement of placentae or ovules in the ovary of a flower is known as Placentation.
• The primary significance of placentation is protecting the developing ovules.
• There are various types of placentation: 
  • ​Marginal Placentation
  • Axile Placentation
  • Free Central Placentation
  • Basal Placentation
  • Parietal Placentation

Explanation:

• The arrangement of ovules within the ovary is known as placentation.
• The placentation is of different types namely, marginal, axile, parietal, basal, central, and free central.

Thus, the placentation in tomato and lemon is axile placentation.

Concept-

• Epiphytes are small plants that grow on other plants in the tropical rain forest.
• They take only space from the host plant.
• Examples of epiphytes are orchids and hanging mosses.

Explanation-

• Velamen is spongy, multiple epidermises that cover the roots of some epiphytic or semi epiphytic plants, such as orchid and Clivia species.
• The function of Velamen is the Absorption of water.
• The velamen of an orchid is the white or gray covering of aerial roots.
• It is many cell layers thick and capable of absorbing atmospheric moisture and nutrients.
• Often, the roots of orchids are associated with symbiotic fungi or bacteria.
• The latter may fix nutrients from the air.
• This functionality allows the orchid to exist in locations that provide a reproductive or vegetative advantage such as improved exposure or reduced competition from other plant species.

Thereby Velamen, the spongy tissue, is present in Epiphytic roots.

Additional Information

Tuberous roots

• The food is being stored in these roots.
• They become swollen and irregular.
• These roots have no definite shape.

Parasitic roots

• The roots of parasitic plants enter the host plant.
• They absorb nutrition from the host.
• An example of these roots is Cuscuta, Viscum.

Breathing roots

• When the quantity of oxygen is low in soil then some roots come out from the soil and helps in respiration.
• An example of these roots is Avicennia.