Class X Chapter 8 – How do Organisms Reproduce Science
Question 1 : How is the process of pollination different from fertilization ? Answer : Pollination is the process of transfer of pollens from anther to stigma . It occurs with the help of certain pollinators such as air , water , birds , or some insects . Fertilization , on the other hand , is the fusion of the male and female gametes . It occurs inside the ovule and leads to the formation of zygote . Question 2 : What is the role of the seminal vesicles and the prostate gland ? Answer : The secretions from seminal vesicles and prostate glands lubricate the sperms and provide a fluid medium for easy transport of sperms . Their secretion also provides nutrient in the form of fructose , calcium , and some enzymes . Question 3 : What are the changes seen in girls at the time of puberty ? Answer : Secondary sexual characteristics in girls :
• Increase in breast size and darkening of skin of the nipples present at the tips of the breasts .
• Appearance of hair in the genital area .
• Appearance of hair in other areas of skin like underarms , face , hands , and legs .
• Increase in the size of uterus and ovary .
• Beginning of menstrual cycle .
• More secretion of oil from the skin , which results in the appearance of pimples . Question 4 : How does the embryo get nourishment inside the mother ’ s body ? Answer : The embryo develops inside the mother ’ s body for about nine months . Inside the uterus , the outer tissue surrounding the embryo develops finger-like projections called villi . These villi are surrounded by uterine tissue and maternal blood . They provide a large surface area for exchange of oxygen and nutrients . Also , there is a special tissue called placenta , which is embedded in the uterine wall . The embryo receives the oxygen and
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