Multicellular organisms can be much larger and more complex. This is because the cells of the organism have specialised into many different types of cells such as nerve cells, blood cells, muscle cells all performing different functions.
Archea can live in extreme environments; Eubacteria cannot.
and
The gene sequences of their rRNA are very different.
Answer:
B. secrete granzymes and perforin.
Explanation:
Perforins are the proteins that perforate the plasma membrane of the target cell and lead to bursting of cells due to holes formed in its membrane. Granzymes are the proteolytic enzymes. They serve to stimulate the target cells to kill themselves by the process of apoptosis.
Binding of natural killer cells to their target cells stimulate the release of granules that are filled with perforins or granzymes to kill the target cells.
Likewise, cytotoxic T cells bind to the infected body cells and release the granules filled with perforins or granzymes to kill those infected cells.
Answer:
1. Endoneurium covers the myelinated or unmyelinated axons. it is a layer of delicate connective tissue that envelops the myelin sheath of each of the myelinated nerve fiber.
2. Perineurium covers fascicles. It is the connective tissue sheath that envelops fascicle of nerve fibers within a nerve.
3. Epineurium covers nerves. It is the outermost layer of dense irregular connective tissue that envelops the peripheral nerve and multiple nerve fascicles.
