Sexual Reproduction in Flowering Plants Test - 95

Flowers which have only stamens are called male flowers or staminate flowers. In the typical flower each flower has both carpels and stamens. In some species, however, the flowers are unisexual with only carpels or stamens. (monoecious with both types of flowers found on the same plant; dioecious with the two types of flower found only on different plants). A flower with only stamens is called as androecious. A flower with only carpels is called as gynoecious.A flower having only functional stamens and lacking functional carpels is called as a staminate flower or (inaccurately) male. A plant with only functional carpels is called as pistillate. Therefore, the correct answer is option C.

Rosary pea (Abrus precatorius) is a slender, perennial climber, that twines around trees, shrubs, and hedges. It is a legume with alternate compound leaves, 2 to 5 inches long, with 5 to 15 pairs of oblong leaflets. 

Nelumbo nucifera, also known as Indian lotus, sacred lotus, bean of India, or simply lotus, is one of two species of aquatic plant in the family Nelumbonaceae. This plant is an aquatic perennial. Under favourable circumstances, its seeds may remain viable for many years, with the oldest recorded lotus germination being from that of seeds 1,300 years old recovered from a dry lake bed. 

Pollinia is a mass of pollen grains which are fused by sticky discs called as corpuscula. This structure originates from a single anther. 
In Rubiaceae family, the anthers are 4-5 in number and are epipetalous i.e. attached to the petals. The anthers of Asteraceae are also epipetalous. 
Myrtaceae family does not show pollinia. 
Asclepiadaceae family show pollinia where the pollinia stick together and transported as a single unit during pollination. Pollination is carried out by insects. Hence, option C is correct. 

Vivipary is a condition where plants produce seeds which germinate before they detach from the parent. 
Xerophytes are terrestrial plants which have adapted to survive in environment with little water, like desert or ice covered region. Seeds of such plants are modified to require more water before germination, so to make sure that there is sufficient supply of water for seedling survival. Hence, xerophytes do not show vivipary. 
Hydrophytes are plants which are adapted to survive in aquatic conditions.
Such plants show reproductive adaptation-
1. Production of buoyant seeds which can float on high flooded water and delay germination process.
2. Plants grow quickly after germination and form an extended shoot on water surface. 
Therefore, hydrophytes do not show vivipary. 
Epiphytes are plants which are not rooted in soil but grows on bodies of other plants. But they are not parasites, they produce their own food. Epiphytes show reproductive adaptations as,
1. They produce colorful flowers to attract many pollinators.
2. They also produce strong nectar to lure pollinators.
3. After pollination they produce large number of small seeds which can be dispersed by wind.
But epiphytes do not show vivipary.
Mangroves are various types of trees of medium height which are found in saline coastal habitat. Vivipary is a type of reproductive adaptation shown by mangroves. Mangroves show adaptation to survive in harsh, unstable, dynamic environment, low oxygen and varying salinity of soils. The salinity of the surrounding water and soil damage the seeds. The unstable flood can destroy the seeds. In such environment, if seeds are dispersed in water then their chances of survival are very less. Therefore, mangroves show vivipary.
Therefore, the correct answer is option C.

The edible parts of the seeds mentioned are as follows,
French Bean- cotyledons, Coconut - endosperm, testa, cotyledon and embryo
cashew nut - cotyledon, litchi - juicy aril,
groundnut - seeds, pomegranate - testa,
walnut - cotyledons, tamarind - mesocarp,
Therefore, the correct answer is option A.

Cypsela Is a simple one seeded fruit which has pappus. This is a dry fruit which is very tiny belonging to the family Asteraceae and also has an additional silken, furry, hairy structure called as the pappus. This plays an important role in seed dispersal. 
Achene is also a dry fruit but does not belong to asteraceae, and lacks pappus. 
A nut is much bigger in size unlike the cypsella and lacks pappus, though it is a dry fruit.
As regma fruit belongs to euphorbiaceae and cypsella belongs to Asteraceae.
Thus, the correct answer is option B.

Many seeds are insensitive to light, but in a number of species, germination is stimulated or inhibited by exposure to continuous or short periods of illumination. So stimulated are many grasses, lettuce, fireweed, peppergrass, mullein, evening primrose, yellow dock, loosestrife, and Chinese lantern plant. Corn, the smaller cereals, and many legumes, such as beans and clover, germinate as well in light as in darkness.
Inhibition by light is found in chive, garlic, and several other species of the lily family, jimsonweed, fennel flower. Sometimes, imbibed (wet) seeds that do not germinate at all in darkness may be fully promoted by only a few seconds or minutes of exposure to white light or to karrikin. The best-studied case of this type, and one that is a milestone in plant physiology, concerns seeds of the Grand Rapids variety of lettuce, which is stimulated to germination by red light (wavelength about 660 nanometres) but inhibited by far-red light (wavelength about 730 nanometres). Red light inhibits stem elongation and lateral root formation but stimulates leaf expansion, chloroplast development, red flower coloration, and spore germination. Such stimulation by red light can be reversed by exposure to far-red light. So, red light is most effective in seed germination compared to green, blue and far red light. 
Therefore, the correct answer is option C.

Tetrazolium salt stains all living tissue in the seed embryo red. Thus, enabling trained analysts to determine the seeds viability or otherwise. The tetrazolium test is used to give a quick estimate of germination potential. The result of a tetrazolium test will generally predict the germination test result closely, however the tetrazolium test will not detect certain types of abnormalities nor will it give any indication of disease levels, chemical damage or dormancy. The viability of a seed is tested by tetrazolium salts. The viable seeds when respire reduce the colourless tetradyes into highly coloured compounds, i.e. 2, 3, 5 triphenyltetrazolium chloride is reduced to triphenylformazon which is red in colour. 
Therefore, the correct answer is option B.

The assertion is correct but the reason for the assertion is not right. Maize is an albuminous seed. The seeds are endospermic or albuminous where the embryo is embedded in the endosperm and nucellus, which the seedling will use upon germination. In maize the pericarp of the fruit is fused with the seed coat referred to as caryopsis. The cob is close to a multiple fruit in structure, except that the individual fruits -the kernels never fuse into a single mass. The grains are about the size of peas, and adhere in regular rows around a white, pithy substance, which forms the ear.
Therefore, the correct answer is option C.