Answer:
4.they are made up of DNA wrapped around proteins
Each person carries 23 pairs of chromosomes in every cell that makes up their body, with the exception of gametes, which contain 23 SINGLE chromosomes. So when a sperm and egg meet, they then have 23 pairs. In the process of meiosis 'crossing-over' occurs, which means that the chromosomes get "shuffled". This means that the child can receive random traits not only from the parents, but also the grandparents. so there is about 2⁴⁶ possible pairings, excluding the risk for things such as Down-Syndrome
Answer: D
Explanation: The villi increases the surface area for food absortion. Each villus has a network of thin and small blood vessels close to its surface. The surface of the villi absorbs the digested food materials.
A disadvantage of coal to liquid production of synthetic fuels is THAT IT REQUIRES MORE COAL MINING.
The coal to liquid production of synthetic fuels involves the conversion of solid coal to liquid fuel.This can be done either directly or indirectly through chemical processes. The process has many advantages, including: improvement in national and economic security, less dependence on foreign oil, provision of some environmental benefits, such as cleaner oil. But one disadvantage of this process is that it requires extensive coal mining.