The skin synthesizes a precursor of CALCITRIOL in response to UV radiation in sunlight.
Calcitriol is also called Vitamin D3; it is the hormonally active metabolite of Vitamin D. It is used as drug to treat bone disorder, hyperthyroidism and calcium deficiency.
Answer;
Primitive streak.
At the onset of the embryonic period, the primitive streak appears. It will eventually become the neural tube.
Explanation;
The primitive streak is a transient structure which forms on day 15 of human development.
It marks the start of gastrulation; the process in which the inner cell mass in converted into the trilaminar embryonic disc.
It originates from the anterior epiblast.
Answer:
HERBACEOUS PLANTS• Support is provided by the turgidity of parenchyma & collenchyma cells & xylem tissues. Parenchyma cells are filled with water turgid• Collenchyma cells have unevenly thickened cellulose walls which provide support in stem & the midrib of the leaves.
hope this answer helps you.....
Answer:
Find the area of a square or rectangle by multiplying the length times the width. This formula looks like l*w. If the length is 5 and the width is 2, the area is 10 square units.
Explanation: