These are the most important 6 biomes:
1. Freshwater
<span>2. Marine
</span>3. Desert
<span>4. Forest
5. Grassland
</span>6. Tundra<span>.</span>
Food moves through the digestive system tract by peristalsis, which is produced by wavelike contractions of INVOLUNTARY muscles
Psychic stimulants include caffeine, cocaine, and various amphetamines. These drugs are used to enhance mental alertness and reduce drowsiness and fatigue.
The tilt of the earth's axis, which essentially "turns" certain parts of earth so that some parts receive more direct sunlight
Ok, so when a horse (with 64 chromosomes) is crossed with a donkey(that has 62 chromosomes), each parent give its child half of its chromosomes. [64/2=32] [62/2=31]. So the mule gets 31 pairs of chromosomes plus 32 pairs of chromosomes. That equals 63 total chromosomes. In order to be a parent, it must give <span>half of its chromosomes to its child. [63/2=31.5] You can't have half a chromosome, so the mule is a sterile organism. Let me know if you have questions.</span>