<span>Composition. (We use the crust-mantle-core terminology to describe differences in chemical composition in Earth's interior. We use the lithosphere- asthenosphere terminology to describe differences the physical state and behavior. Note that the boundaries between layers with different compositions do not occur at the same depths as the boundaries between layers with different physical properties. For example, there is a change in composition when passing from crust into mantle. But there is no change in physical state or behavior at this boundary- the uppermost part of the mantle behaves in the same way that the crust does because it is still far enough below its melting temperature to be a rigid, brittle solid. The transition to a softer, more pliable solid occurs further down within the mantle and this change in behavior occurs with no change in composition.)</span>
Answer:
PETRIFIED WOOD is the answer okkkkkkkkkkkkkkkk
Cell division is the process by which a parent cell divides into two or more daughter cells.[1]Cell division usually occurs as part of a larger cell cycle. In eukaryotes, there are two distinct types of cell division: a vegetative division, whereby each daughter cell is genetically identical to the parent cell (mitosis),[2] and a reproductive cell division, whereby the number of chromosomes in the daughter cells is reduced by half to produce haploid gametes(meiosis). Meiosis results in four haploid daughter cells by undergoing one round of DNA replication followed by two divisions. Homologous chromosomes are separated in the first division, and sister chromatids are separated in the second division. Both of these cell division cycles are used in the process of sexual reproduction at some point in their life cycle. Both are believed to be present in the last eukaryotic common ancestor.
Prokaryotes (bacteria) undergo a vegetative cell division known as binary fission, where their genetic material is segregated equally into two daughter cells. All cell divisions, regardless of organism, are preceded by a single round of DNA replication.
For simple unicellular microorganisms such as the amoeba, one cell division is equivalent to reproduction – an entire new organism is created. On a larger scale, mitotic cell division can create progeny from multicellular organisms, such as plants that grow from cuttings. Mitotic cell division enables sexually reproducing organisms to develop from the one-celled zygote, which itself was produced by meiotic cell division from gametes. After growth, cell division by mitosis allows for continual construction and repair of the organism.[3] The human body experiences about 10 quadrillion cell divisions in a lifetime.[4]
The primary concern of cell division is the maintenance of the original cell's genome. Before division can occur, the genomic information that is stored in chromosomes must be replicated, and the duplicated genome must be separated cleanly between cells.[5] A great deal of cellular infrastructure is involved in keeping genomic information consistent between generations.
A is the correct answer :)))))
<span>Magnetic resonance imaging
is a technology that uses magnetic fields and radio waves to produce high
quality 2 or 3 dimensional images of the brain structure without using
radioactive tracers and ionizing radiation. The magnetic resonance intensity is
proportional to the density of the protons in various tissues.</span>
