Questions

Adipocytes are the major source of leptin production, and plasma leptin concentrations directly correlate with the amount of total body fat.

Adipocytes are highly specialized cells that play a crucial role in the energy balance of most vertebrates.

Adipocytes convert excess energy to tri-acylglycerol and deposit it during feeding in preparation for periods of food deprivation.

Adipocytes may become enlarged by increased fat storage

Syngamy, also known as fertilisation occurs between the male and female gametes. Syngamy may occur either externally, outside the body of organisms or internally, inside the body. Syngamy leads to formation of a specialised cell called diploid zygote.

For “Pay for” means give money to someone for goods received. So, it is the phrasal verb which will make the sentence grammatically correct, as the sentence talks about paying money for buying certain articles. Pay out means the act of receiving money or material gain as a compensation. Pay off means to pay a debt. Pay of has no meaning.