The story of spontaneous generation illustrates that science is capable of doing exactly what it is supposed to do: observe nature and eliminate theories that contradict observations. In this case, the theory that (for instance) flies form spontaneously out of decaying meat was successfully falsified.
Answer: Solar radiation heats the ocean and causes evaporation. Without this, it could not reach the atmosphere to create clouds or precipitation
The lateral hypothalamus signals an animal to start eating, whereas the <span>ventromedial </span>hypothalamus signals the animal to stop eating. So the correct option is the first one.
Answer:
True
Explanation:
The embryonic development of fertilized egg includes cleavage, blastulation, implantation, gastrulation and organogenesis.
Cleavage division divides the zygote into blastomeres. First cleavage division result in two blastomeres, second cleavage division results in a transient three cell stage. Third cleavage division forms 8 blastomere. These result in the formation of a sold ball of cells called morula. Morula is 16 cell stage and it descends towards the uterus in 4-6 days. As the morula enters the uterus, it gets a rich supply of nutrients. Trophoblast cells are formed which secrete a fluid into the interior creating a cavity called blastocoel. The inner cell mass now comes to lie on one side as embryonal knob. With the formation of blastocoel, morula is converted into blastula which is called blastocyst in mammals.
Answer:
<em>Astrocytes</em>
Explanation:
In the central nervous system, astrocytes, also collectively known as astroglia, are distinctive star-shaped glial cells.
It is not well known the ratio of astrocytes in the brain.
Research has found that the astrocyte proportion varies by area depending on the counting technique used and varies from 20% to 40% among all glia.
These fulfill many roles, namely <em>biochemical reinforcement of tumor cells that build the blood-brain barrier, nutritional supply to the nervous tissue, extracellular ion balance maintenance, as well as a function in the brain and spinal cord repair and scarring cycle after severe injuries.</em>
