|
|
Blood is approximately twice as thick as water because of the cells and other components found in it.
The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.
Not getting enough sleep can greatly weaken the immune system. Lack of sleep makes you more likely to catch a cold, or more difficult to fight off an infection.
Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.
Signs of depression include feeling sad most of the time for 2 weeks or longer; loss of interest in things normally enjoyed; lack of energy; sleep and appetite disturbances; weight changes; feelings of hopelessness, helplessness, or worthlessness; an inability to make decisions; and thoughts of death and suicide.
![The tundra at the base of the Torngat mountains in Labrador consists primarily of low-growing mosses](https://biology-forums.com/gallery/47/medium_33_27_08_11_11_56_24_15451996.jpeg)
![The testes. In addition to producing sperm, the testes secrete the male sex hormones, primarily test](https://biology-forums.com/gallery/47/medium_14755_28_08_12_1_42_28_8238159.jpeg)