Sexual Reproduction in Flowering Plants Test - 29

Honey bees convert nectar into honey by a process of regurgitation and evaporation. They store it as a primary food source in wax honeycombs inside the beehive.

The seed coat helps protect the embryo from mechanical injury, predators and drying out. The seed coat develops from the material tissue, the integuments, originally surrounding the ovule. The seed coat in the mature seed can be a paper-thin layer (e.g. peanut, maize, gram) or more thick and hard in honey locust and coconut, or fleshy as in the sarcotesta of pomegranate. 

In botany, a hilum  is a scar or mark left on a seed coat by the former attachment to the ovary wall or to the funiculus (which in turn attaches to the ovary wall). On a bean seed, the hilum is called the "eye".
For some species of fungus, the hilum is the microscopic indentation left on a spore when it separates from the sterigma of the basidium

Perisperm is nutritive tissue in the seed, so functionally similar to the endosperm. But perisperm is diploid as it is developed from nucellus by mitosis, while endosperm is triploid. Hence option C is the correct answer.

Germ pore is the place on pollen grains exine, where the sporopollen is absent. It helps in formation of pollen tube by intine.

Geitonogamy is a fertilization of a flower by the pollen from another flower of the same plant. It is seen in monoecious plants like maize. It is a cross pollination within the same plant. In this, pollens are transferred by insects or winds. 

Flowering plants need to get pollen from one flower to another, either within a plant for self-pollination or between plants of the same species for cross-pollination to occur. However, pollen cant move on its own, so animals or the wind (and water in rare cases) move the pollen for plants.Many flowers use colours to attract insects, sometimes helped by coloured guiding marks. Some have ultraviolet marks that can be seen by insects but are invisible to human eyes. Flowers are often shaped to provide a landing platform for visiting insects or to force them to brush against anthers and stigmas.Some flowers have scent to attract insects. Many of these scents are pleasing to humans too, but not all some flowers attract flies with a smell of rotting meat. Colours cant be seen in the dark, so scent is important for flowers that are pollinated by night-flying insects such as moths. Most bird-pollinated flowers have lots of nectar, often at the bottom of a tube of petals. Birds need to brush against anthers and stigmas when reaching for the sugary reward with their long beaks. Some birds, such as t, stitchbirds and bellbirds, have special brush-like tips to their tongues to help them soak up the nectar.

• 


Monoecious plants are those species that bear both sperm and eggs on the same gametophyte.
• Chara is a genus of green algae in the family Characeae. They are multicellular and superficially resemble land plants because of stem-like and leaf-like structures.
• They are found in freshwater, particularly in limestone areas throughout the northern temperate zone, where they grow submerged, attached to the muddy bottom.
• They prefer less oxygenated and hard water and are not found in waters where mosquito larvae are present.
• They are covered with calcium carbonate deposits. Chara is a genus of green algae in the family Characeae.
• They are multicellular and superficially resemble land plants because of stem-like and leaf-like structures.
• They are found in freshwater, particularly in limestone areas throughout the northern temperate zone, where they grow submerged, attached to the muddy bottom.
• They prefer less oxygenated and hard water and are not found in waters where mosquito larvae are present. They are covered with calcium carbonate deposits.
  Hence, Option D is correct.

Transfer of pollen from an anther of one flower to a stigma of another flower on the same plant is called as geitonogamy. Although geitonogamy is functionally cross-pollination involving a pollinating agent, genetically it is similar to autogamy since the pollen grains come from the same plant. Cleistogamy or automatic self-pollination describes the trait of certain plants to propagate by using non-opening, self-pollinating flowers. Especially well known in peanuts, peas, and beans.