When Did the Universe Cool to a Temperature of 3

question 132

Multiple Choice

When did the universe cool to a temperature of 3 K?

• A) 1 second after the start of the Big Bang, when pair production ceased
• B) 380,000 years after the Big Bang, when the universe became transparent to radiation
• C) 3 minutes after the start of the Big Bang, when primordial nuclear reactions ceased
• D) very recently

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Definitions:

S Phase

The phase of the cell cycle during which DNA is replicated, preparing the cell for division.

Secondary Oocyte

The cell that forms after the first division in oogenesis and can develop into an ovum after fertilization.

Diploid Organism

An organism whose cells contain two sets of chromosomes, one set inherited from each parent, which is characteristic of most adult forms of life.

Spermatogenesis

The process of sperm cell development, occurring in the testes, through which spermatogonial stem cells differentiate into mature sperm.