The correct answer is d. 3.5 billion years.
Prokaryotes were the first forms of life on Earth long before simple multicellular life appeared because of their ability to withstand extreme conditions. It is believed that the first living forms were bacteria combined with archaea in the microbial mat (multi-layered sheet).
Liver
In pediatric patients, the liver and spleen are very large in
proportion to the size of the abdominal cavity and are more easily injured. The
soft, flexible ribs of infants and young children do not protect these two
organs very well and may allow injury to underlying organs, even without fracturing
the ribs.
50% because of the ee and ee
A) This is predator-prey relationship.
B) Species A is prey and species B is predator.
- If prey population decreases in number, the predator population will also decrease because there is not enough food for predators to survive and vice versa.
- If predator population decreases, the prey population will increase because less prey will be eaten by predators and vice versa.
C) Let population A be Zebras, and population B Lions.
From the graph, at the beginning the there is increase in Lions, as well as in smaller rate in Zebras. At one point, the population of Lions begins to decrease, so they will eat less Zebras. This will allow Zebras to increase population. With more Zebras on the menu, more Lions will eat and increase their chance to survive. This leads to decrease in Zebra population. But again, with less Zebras, the Lion population must decrease allowing Zebra population to increase, and so on.
Listed under are the 5 different type of cells found in the epidermis and their description:
1. Stem cells
These are what you call undifferentiated cells. These are cells found in the stratum basale, which is the deapest layer of the epidermis. These cells divide to create keratinocytes.
2. Keratinocytes
The make up the majority of the cells in the epidermis. They synthesize keratin which are proteins that make up your hair, skin, and nails. They can also be found in other organs inside your body.
3. Melanocytes
These cells can only be found in the stratum basale. They synthesize melanin with a brown to black pigment. These dark pigments serves as protection for the skin from harmful UV rays.
4.Merkel cells
Merkel cells are also known as <em>tactile cells</em>. They are the sensory receptor for touch. Merkel cells and the nerve fiber together are called the Merkel disc.
5. Dentritic cells
They are also known as <em>Langerhans cells</em>. They can be found in two layers of the epidermis: the stratum spinosm; and stratum granulosm. They are what you call macrophages that come from the bone marrow. They serve as immune cells that provide protection against toxins, microbes and other pathogens that try to penetrate the skin.
Hope you find some information above that will help you.
