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3., , Ans., , Lid, , Aas., , , , , , , lapeste cence cinerea amnpeineten eterna, , A alia of faaatice of yorcers., | ~ Itisa pre-fertilisation event. |, "= It may involve meiosis or mitosis. |, — It always occurs inside the body of the parent, organism., , Describe the post-fertilisation changes in a flower., , — After fertilisation, the sepals, petals, stamens, style, and stigma of the flower wither and fall off., , ~ The primary endosperm cell undergoes mitosis, and forms the endosperm tissue that is filled with, nutrients,, , ~ Thezygote develops into an embryo (embryogenesis), inside the ovule., , — The ovule develops into a seed., , ~ The ovary transforms into the fruit with a thick, wall, called pericarp., , What is a bisexual flower? Collect five bisexual, , flowers from your neighbourhood and with the help, , of your teacher find out their common and scientific, , names., , A flower having both male (stamen) and female (pistil), , reproductive structures, is known as a bisexual flower., , , , , , , , eg. Common name Scientific name, 1. Mustard Brassica nigra, 2. China rose Hibiscus rosa-sinensis, 3, Pea Pisum sativum, 4. Onion Allium cepa, 3. Rose Rosa indica, , eon mtn mts, , - Ie becomes thick-walled in fungi and lane 4» one 0, resist damage and dessication., , , , , - tt is the process of development of zygote into an embry ., — Itis a post-fertilisation event. |, - It more often involves only mitosis. i, , ~ It may also occur outside the body of parent organism,, as in oviparous animals., , 115 Examine a few flowers of any cucurbit plant and, try to identify the staminate and pistillate flowers,, Do you know any other plant that bears unisexual, flowers?, Ans. Staminate flowers are male flowers which bear, stamens,, Pistillate flowers are female flowers and they bear, pistil/gynoecium, Le. ovary, style and stigma., Papaya, date palm and coconut palm also bear, unisexual flowers., / > Why are offspring of oviparous animals at a greater, risk as compared to offspring of viviparous animals?, The oviparous aninvals lay fertilised or unfertilised, ‘eggs; so their offspring are vulnerable to predators,, which threaten their survival upto adulthood and, , they are also exposed to harsh environmental, conditions., , Ans, , ~ The viviparous animals give birth to young ones;, their offspring are well protected and nourished by, the parent animal.