Answer: Option A. -> True
:
A
In many citrus and mango varieties, nucellus protrude into the embryo sac and develop into embryos. This condition is called somatic apospory.In such cases, seeds possess more than one embryo and this condition is called polyembryony.

Answer: Option A. -> (i)-3n, (ii)-4n & (iii)-5n
:
A
A ‘4n’ female plant on undergoing meiosis forms a ‘2n’ megaspore which develops into an embryo sac with all the cells having a ploidy of ‘2n’. Similarly, a ‘2n’ male plant will form male gametes with the ploidy of ‘n’. Hence, embryo produced is 3n (fusion of ‘2n’ egg and ‘n’ sperm) and endosperm is 5n (PEN formed from the fusion of two ‘2n’ polar nuclei i.e., ‘4n’ and on fusion with ‘n’ sperm forms ‘5n’ endosperm). Perisperm is nothing but thenucellus of female parent which is ‘4n’.

Answer: Option A. -> True
:
A
All hydrophilous plants are hydrophytes as they require water in close proximity for pollination to occur. However, in majority of hydrophytes, like water hyacinth and water lily, flowers lie above the level of water and thus are pollinated by insects or wind as in most of the land plants.

Answer: Option A. -> True
:
A
Plant growth promoters or phytohormones, for example auxins, gibberellins and cytokinins induce growth promoting activities such as cell division, cell enlargement, pattern formation, tropic growth, flowering, fruiting and seed formation in plants.

Answer: Option D. -> Both B & C
:
D
The functional megaspore undergoes free nuclear divisions during the formation of embryo sac. Similarly, the primary endosperm cell also undergoes free nuclear divisions during endosperm development.

Answer: Option A. -> Receptacle
:
A
Flowers are modified shoot parts which bear the reproductive organs of angiosperms, enabling them to carry out sexual reproduction. Flowers arise from a modified stem called the receptacle.

Answer: Option A. -> Viola
:
A
Some plants such as Viola, Oxalis, and Commellina produce two types of flowers - chasmogamous flowers which are similar to flowers of other species with exposed anthers and stigma, and cleistogamous flowers which do not open at all. In such flowers, the anthers and stigma lie close to each other. When anthers dehisce in the flower buds, pollen grains come in contact with the stigma to effect pollination. Thus, cleistogamous flowers are invariably autogamous as there is no chance of cross pollen landing on the stigma. Cleistogamous flowers produce assured seed–set even in the absence of pollinators.

Answer: Option D. -> Cotton
:
D
Short-day plantsflower when their day lengths are less than their critical photoperiods. They are unable to flower during long days with extreme amounts of sunlight or when exposed to a great deal of artificial light. These plants require regular periods of darkness to mature and flower, and they typically begin their growth during the summer months but do not flower until fall, when the days are getting shorter. There are many varieties of short-day plants. A lot of them are very important to agriculture and society, like cotton, rice, and sugarcane

Answer: Option B. -> Length, area, volume, and cell number
:
B
Growth in measured by a variety of parameters like increase in flesh weight, dry weight, length area, volume and cell number. Growth of root and pollen tube is measured in terms of their length, leaf in terms of area, fruit in terms of volume and bacteria in terms of cell number.

Answer: Option C. -> Gibberellins
:
C
Gibberellins were first discovered in rice plants infected with foolish seedling disease or bakane disease by japanese scientist Eiichi Kurosawa in 1926