During the Fourth and Fifth Weeks After Conception, Which of the Following

question 20

Multiple Choice

During the fourth and fifth weeks after conception, which of the following is correct about the embryo?

• A) The limbs and hands have not become apparent.
• B) It grows to a length of 2.5 centimetres.
• C) The heart is fully formed and begins to beat.
• D) The brain begins to appear.

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Definitions:

Igf2

Insulin-like Growth Factor 2, a protein involved in cellular growth, development, and function, playing a critical role in prenatal growth and development.

Igf2r

A gene that encodes the insulin-like growth factor 2 receptor, involved in various cellular processes including growth, development, and apoptosis.

Parental Fitness

The genetic contribution of parents to the next generation's gene pool, usually measured by the number of offspring that survive to reproductive age.

Extrinsic Mortality

The death rate from external factors, outside the organism's control, such as predation or accidents, as opposed to intrinsic factors like aging.