It is the rib cage (thoracic cage)
For the first question, i think the correct answer is A. Normal cells undergo apoptosis while cancer cells don't. For the second question, The answer is option B.<span> </span><span>Cell division has two checkpoints namely, G1
checkpoint and spindle assembly checkpoint. The checkpoint which determines if
division has properly occurred is the G1 checkpoint. At this point, is a damage
in the DNA is detected or the has not reach the optimum size, the cell is
stopped in G1 and is not allowed to proceed to further process.</span>
RNA and DNA-RNA hybrids are more dense than simply DNA if the density of different nucleic acids is tested using a CsCl gradient.
The primary technique employed in molecular biology is the extraction of DNA, RNA, and protein. Scientists can separate materials according to size, shape, and density by using density gradient centrifugation. Isopycnic centrifugation, a sort of density gradient centrifugation that Meselson and Stahl developed, employed a cesium chloride solution to separate DNA molecules solely on the basis of density. Because DNA has hydrogen bonds between its strands, which makes it less dense than RNA, RNA has a far larger density than DNA. RNA can be obtained at the test tube's bottom using a CsCl density gradient and high centrifugation, whereas DNA can be recovered in the middle layer.
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It regulates on/off like a light switch
<span>The characteristics that scientists used to classify living organisms into six kingdoms include the following:
1. Cell type: living organisms are classified into prokaryotes and eukaryotes based on the presence of nucleus and distinct arrangement of the organelles in their cells.
2. Mobility: living organisms are categorized into kingdoms based on their ability or inability to move about.
3. Cell structure: the cells structure was used to divide living organisms into plants and animals. Those living organisms that have cell wall are classified as plants while those who do not have cell wall are classified as animals.
4. Number of cells: living organisms that are made up of only one cell are classified as unicellular while those with many cells are termed multi cellular.
5. Reproduction method: living organisms are classified based on whether they reproduce sexually or asexually.
6. Manner of obtaining energy: living organisms that can prouduce their own food are called autotrophs while those that can not produce their own foood are termed heterotrophs. Plants are essentially categorised as autotrophs while animals are described as heterotrophs.</span>
