HOW MUCH ICE IS THERE ON EARTH?

About one-tenth of Earth's land surface is covered in ice. Built up over thousands of years, most ice occurs in thick ice sheets that cap the land at the North and South Poles. Ice also tops the peaks of high mountains, and rivers of ice called glaciers gouge deep valleys in polar and mountain regions.

Comments

WHY IS BLOOD RED?

Blood is red because most of its cells are packed with a red-substance called haemoglobin. Using this, the red blood cells pick up vital oxygen and deliver it to the body's cells. To achieve this and other roles, such as removing waste, blood is pumped along blood vessels by the heart.

WHY DO IDENTICAL TWINS LOOK EXACTLY THE SAME?

Identical twins happen when a single sperm (male cell), fertilizes a single egg (female cell) that then splits in two. Each one goes on to grow into a baby, but both cells share exactly the same genetic instructions (DNA) . DOUBLE (OR TRIPLE) TROUBLE! The number of births in which twins or triplets are likely to occur naturally: 1: Identical twins 4 in 1000 births 2: Non-identical (fraternal) twins 15 in 1000 births 3: Identical triplets 1 in 100000 births 4: Non-identical triplets 1 in 8000 births

WHY DON'T SOME PLANTS HAVE FLOWERS?

Although many plants use flowers to reproduce, some do not. There are more than 30,000 types of these non-flowering plants. Mosses, for example, release tiny spores that are spread by the wind. Conifers make seeds inside scaly cones. Both spores and seeds grow into new plants. Bristlecone pines are oldest trees on the planet. Growing slowly on cold, windswept mountain sides in western USA, they can live for thousands of years. The oldest specimen is known as Methuselah, and is about 4,800 years old.

Ask me Anything

Search This Blog