Answer:
15. D have specific gened activated
16. G cell division is unregulated
17. D providing information to form proteins
Explanation:
15. When an egg is first fertilised, the cells are very flexible. They are sort of like a "blank slate", and can become any type of cell. From these cells, all the cells in the body are created: brain cells, skin cells, blood cells etc. To become all these different types of cells, they keep dividing, slowly branching off and becoming more specific. This process is called differentiation.
They do this because different patterns and combinations genes are activated that turn them in to these different and specific cell types.
16. One of the hallmarks of a cancer cell is unregulated cell division. Oncogenes start as normal genes (called proto-oncogenes) that function in normal processes, such as the cell cycle, inhibiting apoptosis. However, when they become mutated, they can promote the growth and division of cells and prevent their programmed death. This is because they become more active or present in higher amounts following the mutation. This causes such functions in the cell to become deregulated, leading to uncontrolled cell proliferation and the growth of harmful tumour cells.
17. The central dogma of biology states that DNA --> RNA --> protein. The messenger RNA (mRNA) is transcribed from the DNA. It contains a message that is translated by the protein synthesis machinery to form proteins.
This is how all the proteins in the cell are produced, and the information for how to encode them is entirely dependent upon the sequence of the DNA, which is sent as a coded message in the form of RNA, to the protein synthesis machinery. The protein synthesis machinery makes the proteins according to the DNA sequence (as translated from the mRNA).
You can find the air spaces in the cell of the leaves where
stoma can be located. The stoma allows
for carbon dioxide to come in, and oxygen to go out. A stoma opens into the airspace inside the
leaf. Carbon dioxide, oxygen, water vapour are the gases might you find in the
air space.
Hello!
A polar molecule is where one of the atoms in a molecule has a slight positive charge, and another has a slight negative charge, due to the unequal sharing of electrons.
Water is one of these molecules - the electrons spend more time around the oxygen atom in the center, and less around the hydrogens, so the hydrogen atoms have a slight positive charge, and the oxygen a slight negative.
Therefore, your answer is B, water has a slight negative and a slight positive charge at opposite poles.
Hope this helps!
Answer:
Why don't we have a complete fossil record of all life that's ever lived? Fossil formation requires a rare mix of physical and biological conditions. Fossils must be exposed at Earth's surface to have a chance of being found. Fossils can be destroyed when rocks erode, melt, or change composition.
Explanation:
For many reasons, the fossil record is not complete. Most organisms decomposed or were eaten by scavengers after death. Many species lacked hard parts, which are much more likely to fossilize. Some rocks and the fossils they contained have eroded and disappeared.
Please mark me as the brainliest
Answer:
They became closer to each other.
Explanation:
When skeletal muscles contracts the Z lines that are at the end of every sarcomere became closer to each other due to the fact that the I bands that are attached to the Z lines and contains the myosin filaments move closer to each other interacting with the actin filaments and shorten the the H zone that is in the middle of the sarcomere. In other words, It all becomes compact during a contraction.
