Physical growth and change lecture

What are the three stages of prenatal development?

Germinal stage, Embryonic stage, Foetal stage.

What is the first stage of prenatal development called?

Germinal stage.

At what week does the embryo begin to form basic structures such as limbs and facial features?

At 8 weeks.

What is a teratogen?

Substances or conditions that can damage an embryo or foetus.

What begins to develop during the Germinal stage?

The placenta and umbilical cord.

What are the three layers of cells formed during the embryonic stage?

Ectoderm, Mesoderm, Endoderm.

How much does an infant typically weigh by 12 months?

By 12 months, an infant typically weighs triple their birth weight.

What percentage of its adult weight is a baby's brain at birth?

Approximately 25% of its adult weight.

What is the primary factor influencing physical growth?

Genetics/hereditary.

What is the Wear and Tear Theory?

The theory that the body wears out due to years of use and exposure to environmental stressors.