Sexual Reproduction in Flowering Plants Test - 67

The term “Xenia” was originally coined to refer direct effect of pollens on seed and fruit characters or effect of gene from male parent on development of fruit and seed. However, as of now, it is restricted to denote effect of pollen grains on endosperms. For example- the colour of endosperm in maize is determined by origin of pollens. Option A is correct. Effect of pollen genes on fruit shape and fruit characters is known as metaxenia which makes option C incorrect. Stem is derived from plumule of embryo; likewise, vascular tissues are derived from primary cambium or procambium. Stem and vascular tissues are sporophytic structures, not the products of sexual reproduction and hence, are not affected by pollen grain that is first cell of male gametophyte. Thus, the correct answer is option A.

Calotropis is a genus of flowering plants in the dogbane family, Apocynaceae, first described as a genus in 1810. It is native to southern Asia and North Africa. They are commonly known as milkweeds because of the latex they produce. Calotropis species are considered common weeds in some parts of the world. The flowers are fragrant and are often used in making floral tassels in some mainland Southeast Asian cultures. Fibers of these plants are called as madar or mader. Calotropis species are usually found in abandoned farmland. Lotus is Nelumbo nucifera. Jasmine is Jasminum sp. Oleander is Nerium sp. 

Pollination by agency of insects is known as entomophily or insect pollination. Bees, butterflies, moths and beetles are main pollinating insects. Insect pollinated flowers are large, conspicuous, bright coloured and have pleasant smell. They have nectarines on receptacles or on spurs at the base of flower whorls and produce nectar to attract insects. Option A is incorrect. Pollination by agency of birds is known as ornithophily. The common pollinating birds are squirrels, bats, snails etc. the bird pollinated flowers are colourful, mostly red, produce lots of nectar and also exhibit adaptations to protect nectar from insects. Option C is incorrect. Pollination by bats is known as chiropterophily. The plants produce large, bell shaped and attractive flowers that open at night and produce strong odours and nectar. Option D is incorrect. Pollination by snails and slug is called as malacophily. These flowers have long blooming period to facilitate access of pollen to snails. 

Insect-pollinated flowers are large, conspicuous, bright coloured and have a pleasant smell. They have nectarines on receptacles or on spurs at the base of flower whorls and produce nectar to attract insects. Wind pollination does not require scented colourful flowers which makes option C incorrect. Wind-pollinated flowers have large, conspicuous, broad, well exposed and feathery stigma to catch windblown pollen. This makes option D correct. Sessile stigma has reduced style and stigma is directly seated on the ovary. Presence of sessile stigma will not expose it to wind to catch pollen. Option A is incorrect. A small and smooth stigma has less exposure to wind and less exposed surface area to catch pollen as well as its smooth nature does not grab the wind-blown pollen. Option B is incorrect. 

The coconut tree is in the family of palm trees, and palm trees are monocotyledons. Almonds, mango and sunflower are dicots. 

In agriculture, the majority of the biomass produced comes from monocots. These include not only major grains (rice, wheat, maize, etc.), but also forage grasses, sugar cane, and the bamboos. Other economically important monocot crops include various palms (Arecaceae), bananas (Musaceae), gingers and their relatives, turmeric and cardamom (Zingiberaceae) and the onions and garlic family (Amaryllidaceae). Additionally, most of the horticultural bulbs, plants cultivated for their blooms, are monocots, such as lilies, daffodils, irises, amaryllis, cannas, bluebells and tulips. Maize is a flowering plant and not a dicot or pteridophyte. Almond is a dicot as it has  two cotyledons in their seeds. 

Tradescantia spathacea is boat lily. Calotropis is milkweed. Homo sapien is human. Syzygium aromaticum is cloves. 

The plant which opens during nights and closes in daytime is night queen. It is called as raat ki rani in India. It is an evergreen woody shrub growing to 4 metres (13 ft) tall. The leaves are simple, narrow lanceolate, 6–20 centimetres (2.4–7.9 in) long and 2–4.5 centimetres (0.79–1.77 in) broad, smooth and glossy, with an entire margin.