Basic level of classification of organisms is:

In the figure, ABC is an isosceles triangle (AB=AC) and BD is the bisector of angle B and BD=BC. How much is angle C?

Who named the centre of the cell as nucleus?

Each side of a square is 10 meters long. A rectangle of the same perimeter as this has sides in the ratio 2:3. What is the area of the rectangle in square meters?

One year in the nineteenth century, the mathematician De Morgan remarked, 'my age now is the square root of this year'. When was De Morgan born?