Cyclins
are the chemicals that regulate the cell cycle. Cyclins work by regulating the timing
of the cell cycle in eukaryotic cell. Cyclins activates cyclin dependent
kinases (CDKs) (an enzyme that works by adding <span>negatively charged phosphate groups to other
molecules in a process called phosphorylation) by binding to it to form a cyclin-Cdk
complex. This complex then functions by acting as a signal to the cell to move
to the next cell cycle phase. At the end of the event, the cyclin is degraded, Cdk
is deactivated, therefore signaling exit from a specific phase.</span>
The right answer is 2 and 3.
The applications of spectroscopy are very diverse; they are in many areas: fundamental physics, astrophysics, nuclear physics, plasma physics, solid state physics, materials science, metrology, microelectronics, new light sources, laser isotope separation, and so on. The R.M.N. provided a very powerful medical imaging technique. Other analysis techniques are similar to spectrometry, in the sense that a spectrum is measured as a function of energy or frequency. Acoustic spectroscopy concerns pressure vibrations for which the notions of frequency and wavelength are similar, although the phenomenon is of a nature quite different from electromagnetic waves. Here again, the frequency range extends far beyond the audible frequency range, from infrasound to ultrasound. Mass spectrometry produces spectra as a function of the mass-to-electric charge ratio of atomic or molecular ions.
By using the legend below the diagram, you can assume that Phase 1 indicates that meiosis has occurred because of the color of the arrow. The dark gray indicates haploid, and haploid is the result of meiosis. Diploid is the result of mitosis.
Another indication is the presence of sex cells or gametes in Phase 1. Meiosis produces gametes and in phase 1, you can see that egg cells and sperm cells were produced.
Prokaryotic cells: lack membrane-bound organelles, relatively small - typically less than 10 μm in size.
Both cell types: use ribosomes to synthesize proteins, contain DNA.
Eukaryotic cells: complete copy of DNA stored in multiple chromosomes.
In particular, prokaryotic cells have no nucleus and no membrane-bound organelles, therefore their ribosomes float freely intracellularly. On the other hand, eukaryotic cells have nucleus and membrane-bound organelles. Also, their DNA is bound to proteins and stored in the form of chromosomes in the nucleus.
