Mitochondria - The mitochondria is referred to as the power house of the cell. Its main function if to produceenergy for cell by the process of cellular respiration. The energyproduced is ATP. Endoplasmic Reticulum - It is a network for transportation of certain substances in and out of the nucleus.
The answer is C) Cloning eliminates the ability to sexually reproduce and provide genetic variability.
In the future, there is no variability in the genes in the clones given that they are the exact copies of the "parent" produce. All should be identical without differences and variations. Although Farmer Brown doesn't want this to happen that's is what he is reluctant to listen to Farmer Green's advice.
ANSWER:
Most types of cancer are believed to begin with a random genetic mutation. This is followed by mutations, which endow the cancer cells with properties allowing them to grow without normal controls to become a tumor.
Mutation is any change in the DNA sequence of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment.
Genetic Mutations that lead to cancer cell formation can occur in two forms:
1. GROWTH-PROMOTING GENES are commonly mutated in cancer cells, becoming SUPER-ACTIVE and producing cells that are too strongly stimulated by growth receptors.
2. Mutations can INACTIVATE the genes that suppress cell proliferation or those that signal the need for apoptosis. These genes are known as TUMOR SUPPRESSOR GENES.
They are accepted as true until they are proven false. Once a theory has been tested and it is wrong, then it is no longer true.