General Science Questions

The troposphere is the lowest layer of the Earth's atmosphere. The air is very well mixed and the temperature decreases with altitude. Air in the troposphere is heated from the ground up. The surface of the Earth absorbs energy and heats up faster than the air does.

Kingdom is the smallest level of classification.

The level of classification from largest to smallest is :

* Domain

* Kingdom

* Phylum

* Class

* Order

* Family

* Genus

* Species

An eclipse happens when a planet or a moon gets in the way of the sun's light. Our planet Earth experiances two types of eclipses. They are Solar and Lunar eclipses.

Solar Eclipse : This occurs when The Sun, the Moon and the Earth are in a straight line. The moon being in middle blocks sun rays falling on the Earth.

Lunar Eclipse : The Sun, the Earth and the Moon are in a straight line. The Earth being in middle and moon in the shadow of Earth behind it.

Healthy blood pressure ranges from 120/80 to 90/60.

Potentially hazardous foods are foods that might contain food poisoning bacteria and are capable of supporting growth of these bacteria or formation of toxins to levels that are unsafe for consumers, if the foods are not stored at correct temperatures. Toxins are poisonous chemicals produced by some types of bacteria.

The food can be left at room temperature until it reaches 60 deg C because food-poisoning bacteria will not multiply at 60 deg C or above. However, do not leave food cooling at room temperature unless you are sure that the temperature of the food is still at least above 60 C.

In humans all reproduction is sexual. It involves joining together haploid gamete cells from each parent with half the normal number of chromosomes to make a new cell containing both parents' genetic material. This is a diploid zygote. The cells from each parent that combine to form the zygote are called gametes.

Meiosis produces haploid gametes from a diploid parental cell.