The two biggest reasons for children spending less time outside are the development of technology and the safety issues. The development of technology brought in our homes countless forms of having fun which is very important to children. The mobile phones, PC's, laptop's, tablets, Sony Play Station, as well as lots of technologically improved toys, made the children stay at home since they have the fun indoors, and not be interested in going outside and in nature. Also the safety issues in lots of parts in the world made the parents to restrict the children to the indoors environment.
Answer:
The Rf values indicate how soluble the particular pigment is in the solvent by how high the pigment moves on the paper.
Explanation:
The Rf values indicate how soluble the particular pigment is in the solvent by how high the pigment moves on the paper. Small Rf values tend to indicate larger, less soluble pigments while the highly soluble pigments have an Rf value near to one.
Answer:
Blood Brain Barrier(BBB)
Explanation:
This is a biological interface of special endothelial cells of astrocytes, pericytes , capillaries, neurons and other structures, acting as a physical barrier or gate separating the Central Nervous system from the peripheral blood circulations. Thus it formed a tight junction serving as a physical barrier to selectively regulate the entrance of substances from the cerebral blood flow into the brain, therefore maintaining homeostasis of the brain.
From above any substances absorbed into the blood stream irrespective of the mode of entry are transported through the BBB, and are selectively regulated to enter the brain cells by the BBB's interactions with the blood vessels, hormones etc.
Basically it allows the passage of nutrients, a few drug, hormones and resists certain toxins and pathogens for the brain homeostasis.
Answer:
A. chromosomes
Explanation:
Chromosomes are structures found in the center (nucleus) of cells that carry long pieces of DNA. DNA is the material that contains genes and is the building block of the human body.
Chromosomes come in pairs. Normally, each cell in the human body has 23 pairs of chromosomes (46 chromosomes in all), of which half comes from the mother and half from the father.
