The correct answer is: When a sperm cell penetrates the oocyte membrane
The oocyte (is arrested at an early stage of the first meiotic division as a primary oocyte. During each menstrual cycle, one the day before ovulation gonadotropin hormone (luteinizing hormone) stimulates completion of meiosis 1. After the meiosis 1, 2 haploid daughter cells are formed: one becomes the secondary oocyte the other forms the first polar body. Newly formed secondary oocyte starts meiosis 2 which arrests at metaphase which will continue after the fertilization.
Her exposure to passive smoking during pregnancy put her and her baby at risk. Some of the health conditions associated with passive smoking during pregnancy are early birth, childhood respiratory diseases, miscarriage, learning or behavioral deficiencies and low birth weight.
Passive smoking is the involuntary inhalation of smoke by persons that are not the active smoker. Passive smoking takes place when tobacco smoke fills an environment which causes its inhalation by people that are present within that environment. Passive smoking can result in dangerous health conditions.
Answer:
an energy source for cell processes
Explanation:
The nucleus, specifically the DNA of it.