Answer:
The correct order is F, E, C, G, H, A, D, and B (look at the image in the attached files)
Explanation:
- <u>Interphase</u><u>:</u> Stages G1, S, and G2. At this point probably, the chromatin duplication has already occurred, but it is still lax or dispersed. It has not condensed yet. Two pairs of centrioles are outside the nucleus (FIGURE F)
- <u>Prophase</u>: Centrioles move forward to the opposite poles of the cell. Chromatin is condensed and individual chromosomes are now visible. The nuclear membrane breaks into many pieces. Spindle apparatus -microtubules- forms. (FIGURE E)
- <u>Metaphase:</u> The polar and the kinetochore fibers drive each individual chromosome to the equatorial plane. This stage ends when all the chromosomes are completely arranged in the medial area. (FIGURE C)
- <u>Anaphase</u>: Sister chromatids separate and move to the opposite poles of the cells, driven by the microtubules. In each pole, there are a pair of centrioles (FIGURE G and H).
- <u>Telophase</u>: The nuclear membrane rearranges. Each sister chromatid becomes now a new chromosome. There is a pair of centrioles outside each of the nuclei. (FIGURE A)
- Cytokinesis occurs at the end of the cell division. The rest of the cell is divided into two new daughter cells. Each daughter cell is an identical copy of the other cell, with the exact same genetic material (FIGURE D).
- Decondensation of the genetic material of each new cell (FIGURE B).
Answer: Transducting the signal from an activated receptor to the next protein in the pathway.
Explanation:
G-proteins are a family of proteins whose main function is to carry a signal from a receptor on the cell membrane to one or more target proteins. So, G-proteins are very important in signal transduction. They depend on the nucleotide guanosine triphosphate (GTP) for activation.
They are the third largest family of proteins in eukaryotic cells and hundreds have been described. G-proteins are involved in signal transduction in many different ways, which is why there are so many different types of these proteins. <u>They can be involved in signalling the activation or silencing of DNA translation, in the reception of hormonal and neuronal signals, etc.</u> They are characterized by their interaction with guanosine triphosphate (GTP) leading to hydrolysis of the nucleotide to guanosine diphosphate (GDP). In this way, a stimulus from outside the cell, a ligand for example, accesses the cell's receptor associated with G-protein or GPCR, triggering a cascade of enzymatic activities or second messengers in response. Therefore, GTPase activity is crucial for their functioning as biological switches.
G-protein-coupled receptors (GPCR) comprise the targets of several biogenic amines, eicosanoids, and other molecules that send signals to target cells such as lipids, hormonal peptides, opiates, amino acids (GABA), and many other protein peptides and ligands. Effectors that are regulated by G-protein include enzymes such as adenyl cyclase, phospholipase C, phosphodiesterases and plasma membrane ion channels selective for Ca²+ and K+.
Also, because of their number and physiological importance, GPCRs are widely used targets for drugs.
<span>They are the sites of reactions that convert solar energy into chemical energy.
</span><span>They have membranous sacs called thylakoids that are surrounded by a fluid called stroma.
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<span>They contain the green pigment chlorophyll.</span>
Answer:
Small animals that live in the splash zone can avoid desiccation by closing their shells tightly to seal in moisture. Some animals, like crabs and marine snails and bivalves, have thick, tough outer coverings to slow evaporation.
Explanation: