They are called stem cells. This cells are undifferentiated which means it can specialize in other types when it receives the right stimuli. They can divide through mitoses and become more stem cell or become a bone, muscle, blood cell, etc.
They can have 2 origins: embryos or some human tissue; their function is to regenerate or substitute damaged cells
The book is lifted upward, but gravity points down, so the work done by gravity must be negative (so you can eliminate options 1 and 3).
The force exerted on the book by gravity has magnitude
<em>F</em> = <em>mg</em> = (10 N) (9.80 m/s^2) = 9.8 N ≈ 10 N
You raise the book 1.0 m in the opposite direction, so the work done is
<em>W</em> = (10 N) (-1.0 m) = -10 J
Answer:
Explanation:
There are different theories and evidence about the big bang, in this case, we're going to see three evidence.
The galaxies are moving from us, this means space is expanded, this in consequence Big Bang's explosion.
The cosmic microwave background radiation is related to the early warmth of the universe.
The observed abundance of hydrogen, helium, deuterium, lithium, these are checked from the spectra of the oldest stars.
They do. mostly because they want validation from others
