Answer:
D. Several cells are in the process of dividing into two new cells
Explanation:
The universal cell theory which was proposed in 1838 and contributed by three scientists namely: Theodor Schwann, Rudolf Virchow, and Mathias Schleiden, consists of three components namely:
1) Cell is the basic and functional unit of life
2) All living organisms are made up of one or more cells.
3) All existing cells arise from pre-existing cells.
Hence, in this question involving a scientist who is observing living Cells in a Petri Dish under a Compound Light Microscope, the observation that "Several cells are in the process of dividing into two new cells" provides evidence to support one of the three components of the cell theory ( all living cells arise from preexisting cells).
The reproduction is the process of forming new cells from the pre-existing cells. Another term used for this process is <span>cell division.</span>
The answer is vacuole and centriole lysosome. An animal cell contains all 3.
An animal cell does not have chloroplasts and a cell wall(a plant has those things). A plant uses chloroplasts (that contains chlorophyll) for photosynthesis. A cell wall is to give the plant a rigid shape(that's why most plant cells look rectangular while animal cells look circular).
Hope this helps :)
Answer:
Insulin is a protein hormone which binds to the membrane receptor where as steroid hormones bind to the intracellular receptors.
Explanation:
Hormones can be divided into two groups based on their binding with receptor. Some hormones are water soluble like protein or peptide hormone (example is insulin) and catecholamines. These water soluble hormones cannot cross the plasma membrane of the target cell and thus bind to the membrane receptor. Binding to the membrane receptor leads to activation of intracellular enzymes which bring the physiological change. Steroid hormones in the other case can cross the plasma membrane and then bind to the intracellular receptors. The hormone receptor complex then either binds or activates specific portion of DNA to bring the physiological change.
Insulin is made by beta cells islets of Langerhans in the pancreas. It controls the levels of glucose. It is a small protein made of two polypeptides, one of 21 amino acids and the other of 30 amino acids. These two are called A chain and B chain and are linked together by disulphide bonds. The pro-hormone contains an extra stretch called C-peptide. During the maturation process the proinsulin looses the c-peptide to become mature insulin protein hormone. An american company called Eli Lilly, for the first time made recombinant human insulin.
