General Science Questions

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.

The nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body.

In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body.

The nervous system has three main functions:

* To collect sensory input from the body and external environment.

* To process and interpret the sensory input.

* To respond appropriately to the sensory input.

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.

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.

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

An orthodontist is the type of doctor that specializes in teeth and jaw alignment. When the teeth don't align properly, it can cause uneven wear in the teeth.

The jaw is a hinge joint. Strong muscles in the face open and close the jaw. Teeth are implanted in the jaw and serve to rip, tear and crush food in preparation for swallowing it.