Rickets develops in growing children who are not exposed to sunlight and have a deficiency of vitamin D, phosphorus or calcium. The disease leads to symptoms such as softening/weakening of the bones, muscle weakness and delayed formation of teeth. The disease is most often observed in young children that are aged between 6 to 24 months of age.
Answer:
The Bathyal zone is the hardest to survive in.
Explanation:
Technically, the entire ocean is difficult to survive in. There's no oxygen and lots of scary ocean predators.
But the Bathyal zone, which is 1000 - 4000 meters below the surface of the ocean has no sunlight, making most of the sea creatures there have no eyes. Because this zone is so dark, with little food to survive in, fish don't hang out here.
(I suggest just staying home)
Answer:
The correct option is D. Crossing over and independent assortment are the causes of genetic variation.
Explanation:
In the process of meiosis, crossing over is a phenomenon through which exchange of genetic segments takes place among the homologous chromosomes.
The process of independent assortment describes how different genes assort differently during meiosis.
Both the process of crossing over and independent assortment are the basis of the genetic variations seen in the world.
Smooth muscles are the hollow organs like the stomach, and digestive system but they are also walls of blood vessels.
-walls of stomach
-walls of blood vessels
-ureters
-intestines
-iris of the eye
-etc
