Question

Layout References Mailings Review View A A Aa A Eva * ALAM AaBbCcDdE AaBbCcDdE AaBbCcD ABCD El AaBb Bb CODE No Spacing Heading1 Heading 2 Subtitle Part D. Double Fertilization 24. Why is "triploid" an appropriate description of the endosperm nucleus? 25. Is the zygote haploid, diploid, or triploid? 26. What is the developmental fate of the primary endosperm nucleus? Of the zygote? 27. What is function of the endosperm? 28. Compare the function of the endosperm with that of the white, endospermlike tissue in a pine seed. Exercise 3: Fruit Development Part A. The Bean (Phaseolus vulgaris) Flower and Fruit 29. Identify and label the parts indicated in manual Figure 12-2. (Be familiar with them.) 30. What has become of the various parts of the flowers during development of the fruit? 31. How many locules are there in the ovary you are examining? 32. Identify and label the parts indicated in manual Figure 12-4. (Be familiar with them.) Ecolish Laited States Focus E-

Answer 1

Q.24. Answer- Endosperm is formed by the fusion of binucleate central cell (2n) and sperm cell(n) and the resulting cell is triploid (3n) which develops into the endosperm. So that "triploid " is an appropriate description of the endosperm nucleus.

Q.25. Answer- Zygote is diploid as it is formed by the fusion of haploid egg cell (n) and haploid sperm cell(n). Do that zygote is diploid (2n).

Q.26. Answer-

1. Primary endosperm nucleus (3n) formed by fusion of secondary nucleus of central cell with sperm divides mitotically and develops into endosperm. Fate of primary endosperm nucleus is to develop nutritive tissue endosperm.

2. Fate of zygote is to develop into larger multicellular organism. Zygote (2n) divides by mitotic divisions and develops in embryo. Then embryo further develops into organism.

Q.27. Answer- Function of endosperm is to nourish developing embryo as endosperm is rich in starch in large amounts and also contains oil and proteins.