The immune system has many kinds of white blood cells to fight infections. HIV finds the white blood cells, called CD4 cells. But with cancer the white blood cells are being killed off.
<span>(2) increased exposure to ultraviolet light. The ozone layer protects us from UV light.</span>
Answer:
<u>Oxbow lake is formed when a bend in a river is cut off to form a lake.</u>
Explanation:
- <u>OPTON A - It is formed as lakes grow larger due to erosion and begins to look like an ox. </u>
This statement is incorrect , as the shape of the oxbow lake is not like an ox , it is a <u>horse-shoe shaped lake .</u>
- <u>OPTION B - It is formed when a bend in a river is cut off to form a lake.</u>
This statement is correct , as An oxbow lake is a U-shaped lake that forms to create a free-standing body of water when a large meander of a river is cut off.
- <u>OPTION C - It is formed when a delta grows large enough to cut off a river to form a lake. </u>
This statement is also wrong, as a<u> river delta</u> is specified by this statement.
- <u>OPTION D - It is formed when a dam stops the flow of a river and creates a lake.</u>
This statement is also false, since the creation of a<u> reservoir</u> is established by this statement.
<u>FORMATION OF OXBOW LAKE -</u>:The neck of the meander gets narrower and narrower progressively. The curve gradually grows so close that the river slices through the neck of the meander to take a new, straighter path. Sediment locks the end of the old loop over time. This leaves a region of water that is different, called an oxbow lake.
Hence , <u>the correct option is B.</u>
Answer: Earth will always be the most accessible habitable planet for study. Consequently, studying the origin and earliest evolution of life, along with the long-term evolution of the Earth's environments, helps us understand why the Earth became habitable and why terrestrial life has persisted for billions of years.
No, the genetic information in parent cells is copied exactly and passed to daughter cells