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What happens when double fertilization occurs?
a. Two zygotes are formed, but only one survives.
b. Two sperm fertilize the egg, forming a triploid zygote.
c. One sperm fertilizes the egg, while another sperm fuses with the polar nuclei.
d. One sperm fertilizes the egg, while two other sperm fuse with a polar nucleus.
Introduction:
Double fertilization is a complex fertilization that occurs in the flowering plants (angiosperms). This gives rise to endosperm apart from the zygote.
Answer to Problem 1TYK
Correct answer:
Double fertilization is a mechanism where one sperm fertilizes the egg and another sperm fuses with the polar nuclei.
Explanation of Solution
Explanation/Justification for the correct answer:
Option (c) is given that double fertilization occurs when one sperm fuses with an egg and another sperm fuses with the polar nuclei. One of the sperm fuses with the egg cell and forms a diploid zygote, while the other sperm fuses with the two polar nuclei and forms a triploid cell. Hence, Option (c) is correct.
Explanation for incorrect answers:
Option (a) is given that double fertilization occurs when two zygotes are formed, but only one survives. Only one zygote is formed in double fertilization. So, it is a wrong answer.
Option (b) is given that double fertilization occurs when two sperms fertilize the egg, forming a triploid zygote. One of the sperm fertilizes the egg and other one fuses with the two polar nuclei. Both of them do not fertilize the egg. So, it is a wrong answer.
Option (d) is given that double fertilization occurs when one sperm fertilizes the egg, while two other sperm fuse with a polar nucleus. This process does not involve three sperm. Only two sperm are required: one sperm fuses with the egg and another one with the polar nuclei. So, it is a wrong answer.
Hence, options (a), (b), and (d) are incorrect.
Thus, double fertilization is a process that involves the fertilization of the female gametophyte with one male gamete and fusion of another male gamete with the polar nuclei.
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Chapter 38 Solutions
Biological Science (6th Edition)
- Which mechanism prevents an ovum from being fertilized by multiple sperm cells? A. Once a sperm penetrates the jelly-like coating of the egg, no other sperm cell can penetrate the coating. B. When a sperm fuses with the plasma membrane of the egg, depolarization of the membrane occurs. C. The egg can survive in the Fallopian tube for 24 hours s it does not have mitochondria to produce energy. D. When more than a single sperm cell fuses with the plasma membrane, multiple zygotes can form, leading to the twin or triplets.arrow_forwardHow do you expect Kartagener syndrome leads to infertility? A. The lack of a plasma membrane means that pathogens and foreign substances can permeate the sperm and damage the DNA B. The lack of microtubules mean the sperm do not have tails and cannot swim to fertilize the egg C. The lack of dynein means that the sperm cannot bend their tails to swim and fertilize the eggarrow_forwardThe process forming the neural tube and plate via the intercalation of cells along the medial-lateral axis and extension along the anterior-posterior axis occurs is called? a. neurulation b. embryogenesis c. convergent extension d. morphogenesisarrow_forward
- Which cell contributes the necessary nutrition to the growing zygote? a a polar body b the egg cell c a spermatocyte d the sperm cellarrow_forwardA secondary spermatocyte has 12 chromosomes. How many chromosomes will be found in the primary spermatocyte that gave rise to it? a. 6b. 12c. 18d. 24arrow_forwardExternal fertilization occurs in which type of environment? a. aquatic b. forested c. savanna d. steppearrow_forward
- What would happen if the trophoblast did not secrete hCG upon implantation of the blastocyst? a. The cells would not continue to divide. b. The corpus luteum would continue to produce progesterone and estrogen. c. Menses would flush the blastocyst out of the uterus. d. The uterine mucosa would not envelop the blastocyst.arrow_forwardHow many functional eggs (ova) result from one oogonium? A. 1 and 3 polar bodies B. 18 C. 4 D. 16arrow_forwardIn which phases in meiosis is variation of genetic makeup accomplished? a. Prophase I, Anaphase I and Anaphase II b. Prophase II, Anaphase I and Anaphase II c. Prophase I, Metaphase I and Anaphase II d. Prophase II, Metaphase I and Metaphase II If 6 cells undergoing celll division has 12 chromosomes, how many chromosome will there be in the daughter cells after mitosis and meiosis II respectively? a. 6 and 12 b. 12 and 6 c. 6 and 3 d. 6 and 6 In meiosis, the number of chromosomes of the mother cell compared to the resultant daughter cell's chromosome is A. doubled B. halved C. tripled D. the same Elongation of the cell undergoing the last phases of mitosis is due to A. movement of the chromosomes to the opposite poles B. increase in the volume of the cytoplasm that should be contained C. depolymerization of the spindle fibers connected to the kinetochore D. polymerization of the spindle fibers not connected to the kinetochorearrow_forward
- Which statement relating to frog gastrulation is INCORRECT? a. A second set of bottle cells migrates inward to create the ventral blastopore lip. b. Gastrulation begins in the gray crescent where bottle cells invaginate. c. Cells just below the DBL begin to invaginate. d. The yolk plug is not internalized and will become part of the ectoderm.arrow_forwardThe process by which the structure labeled B is released from the structure labeled A is known as? A. differentiation B. ovulation C. gastrulation D. germinationarrow_forwardOf the following processes, which occurs last during embryonic development?a. cleavageb. neurulationc. gastrulationd. fertilizationarrow_forward
Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College
