Answer:
An explosion of a star= Supernova
The dense remains of a star= Neutron star
A large mass of gas and dust= Nebula
Explanation:
Stem cells arise from the inner mass of the cell
Signalling factors trigger differentiation in stem cells
Genes that lead to the production of undifferentiated blood cells are activated
Signalling factors cause undifferentiated blood cells to produce red blood cells
Explanation:
Red blood cells are formed in the bone marrow. The precursor to the RBC is stem cell which is undifferentiated and pluripotent. The stem cell gets differentiated to form immature RBCs. Immature RBC then gets divided and becomes mature. Stem cell giving rise to RBC is called Haemoctytoblast. The process of erythropoiesis takes 2 days to form new red blood cells
The main difference between a prokaryotic cell and a eukaryotic cell is that the prokaryotic cell have no true nucleus instead its genetic material is just suspended in its cytoplasm termed as nucleoid. The nucleus when viewed under the microscope is a membrane bound which is easily distingushable compared to the nucleoid.
Another distinguishing feature is that prokaryotic cells are usually smaller than eukaryotic cells.
