Word: cytoplasmic
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...Cell Theory, formulated in 1839, states that all living matter is composed of cells, which are made up of nuclei and cytoplasm. In the last two decades scientists have found that DNA, a long double--chained molecule found in the nucleus, carries the cell's genetic information. This information is the blueprint that describes how the working parts of the cell, the proteins, should be assembled from 20 building blocks, the amino acids. Thus DNA ultimately determines the cell's function. The DNA's information is transferred to RNA (the cell's working manual), which is chemically like DNA except...
...blood cells, which produce hemoglobin, have the same information as muscle cells, although obviously have widely different functions. Cell specialization thus may depend on the process by which the cell chooses which genetic information to copy into RNA and, perhaps more importantly, to transport and use in the cytoplasm...
...Next, the Cliffie has to decide whether or not the book is worth reading after all. She may carry it with her to the reading room or she may immediately discard it in the stacks. Similarly, not all the information which is copied into RNA is transported to the cytoplasm. Finally, as the girl may postpone reading the tome once in the reading room, so sometimes the RNA message is not immediately utilized in the cytoplasm. On the other hand, the girl may fall in love with the book and decide to carry it with her forever. Likewise...
While experimenting in 1948, Geneticist Hannes Laven of the Johannes Gutenberg University in Mainz discovered that common mosquitoes from Paris that were mated with members of the same species from Hamburg would not produce offspring. The reason for this sterility, he determined, was a difference in the cytoplasm (the protoplasm surrounding the cell nucleus) between the Paris and Hamburg strains of mosquitoes. Because of this difference, the egg cells of the females of one strain could not accept the sperm cells from males of the other strain, causing the female to lay infertile eggs. This Franco-German incompatibility...
...remarkable pictures clearly shows that protein molecules eventually used by the developing plant are rearranged during anabiosis into physiologically inactive crystals-a structure that scientists had suspected but never observed. Other photographs reveal the protective shift of tiny sacs of fluid called vacuoles, which are distributed through the cytoplasm of a young, active cell. During anabiosis, they line up in rows against the inner cell wall, probably to strengthen and insulate it against long periods of heat or cold, and to facilitate the rapid absorption of water when it becomes available...