I believe the answer is B. <span>warm air is denser then cold air</span>
I suppose it's a zygote. In haplontic life cycle haploid gametes fuse together creating the zygote (diploid) that promptly divides meiotically creating 4 haplontic cells serving as spores.
Answer
At week 5-6 of gestation, the baby’s heart starts beating.
Explanation
Fertilization occurs in week 3 followed by implantation in week 4.In week 5 the levels of hormones increases with formation of the baby’s heart and circulation system. In week 6, the neutral tube closes followed by development of structures necessary to form eyes and ears. The head of the baby develops at week 7 followed by nose in week 8 and toes in week 9.
