Answer:
the petrified log looks like the original tree.
Explanation:
A tree to be petrified first needs to be buried. An element laying on the surface can not be petrified because it is exposed to many different factors (such as<em> organisms, microorganisms, climatic conditions</em>, etc.), that affect the petrification process. So, in the case of a fallen tree, first, it needs to be covered by many sedimentary layers. Once it is underground, it also needs the presence of underground water and minerals. Water replaces the original organic material with minerals (silica, calcite, and pyrite). This replacement process results in the conversion of the woody material into a fossil of the original material. Very often, the tree details are so preserved that the fossil looks exactly like the original trunk.
Depending on the preservation degree, a fossil can be useful for different studies about the past.
Watson and Crick's model explained mutability because bases pairs can suffer changes (mutations) during DNA replication. Moreover, this model also explained stability because DNA strands are held together by hydrogen bonds.
Deoxyribonucleic acid (DNA) is a double helix molecule composed of two long chains of four types of nucleotides, each containing one different nitrogenous base, i.e., Adenine, Guanine, Cytosine and Thymine.
In Watson and Crick's model, both DNA strands are held together by hydrogen bonds between nitrogenous bases on opposite DNA strands, thereby providing stability to the DNA molecule.
In DNA, Guanine always pairs with Cytosine by three hydrogen bonds, while Adenine always pairs with Thymine by two hydrogen bonds.
Moreover, Watson and Crick suggested that mutations could occur as a consequence of a base occurring very infrequently in one of the less likely tautomeric forms during DNA replication, thereby also explaining the mutability of life.
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Answer:The amount of each element that begins photosynthesis equals the amount of each element that is produced
Explanation:
Answer:
b. heat energy
Explanation:
Water, which is able to exist in three different states moves from one form to another. Water can move from the ocean to the atmosphere via a process called EVAPORATION. During the process of evaporation, the sun plays a major role by supplying the HEAT ENERGY required to change water from its liquid form in the ocean to its gaseous form in the atmosphere.
Water cycle of the earth helps ensure that water is not lost in any of its forms. Liquid water stored in the ocean gets evaporated as a result of heat energy into the atmosphere as water vapour.
Plasma membrane is a part of the cell made of a lipid bilayer and an embedded protein layer. It protects the cell from the surroundings and also controls the materials leaving or entering the cell. The membrane is semipermeable and therefore allows certain materials to enter or leave the cell. In this case, the plasma membrane may prevent unlimited flow of water into or out of the cell.
