Sometimes, the dark spots on the marshmallow can fall off of the marshmallow. This means that, the system does not need to include the pieces that fell when determining the mass before and after.
DNA ligase is an enzyme that repairs irregularities or breaks in the backbone of double-stranded DNA molecules. It has important role in the process of DNA replication and DNA repair. It has three general functions: It seals repairs in the DNA, it seals recombination fragments, and it connects Okazaki fragments (small DNA fragments formed during the replication of double-stranded DNA). DNA ligase functions by forming a bond between the end of a “donor” nucleotide and the end of an “acceptor” nucleotide.
Answer:
It has a pH of 7, so your answer is therefore B.) 7.
Thomas Malthus was economist who proposed that human populations grow faster than the resources they depend on which becomes limiting factor for them, causing the increase of populations but also increase of famine and diseases. As a consequence, the weakest members die. Darwin linked this with the “survival of the fittest" (naturals elections favors the best suited for reproduction and survival).
Georges Cuvier was anti-evolutionist and religious man, but he did have influence on Darwin theory of evolution (natural selection). He was against linear system of classification so, his believes that there is more than one lineage for species helped Darwin shaped his theory.
Charles Lyell geologists who believed that geologic processes that were at the beginning of time were the same ones that were happening at the current time (processes work the same way through time). He explained that slow changes built up over time, so Darwin linked that with the way that life on Earth changes. (small adaptations that accumulated over long periods of time change a species).
Answer:
Helper T cells stimulate B-cells to produce antibodies and killer T cells to destroy the non-self cells. Cytotoxic T cells on the other hand are direct attack cells. They can kill the micro organisms by creating pores on the invader's cell.
Explanation:
T lymphocyte mediated immunity of cell mediated immunity do not secrete antibodies but they help stimulate the B cells to produce them. Immature T cells are produced in bone marrow from where they migrate to thymus via blood. In the thymus maturation of T cells occur and then they migrate to lymphoid tissue and get differentiated into three types:
a. Helper T cells: As the name suggests, they help in activating other immune cells, in other terms they are the regulator of virtually all functions of immune system. Protein mediator called lymphokines are produced by these helper T cells in order to regulate the immune functions. Some examples of these lymphokines are: Interleukin-2 interleukin-3, interferon gamma. T helper cells stimulate the B-cells to produce antibodies.
b. Cytotoxic cells or killer T cells: The lymphokine interleukin-2 is responsible for the growth and proliferation of both cytotoxic T cells and suppressor T cells. With the help of receptor proteins on the surface of killer T cells, they bind to the specific antigen. After binding, they secrete a pore forming protein called perforins which create pores on the invaders cell membrane for water to enter into it thereby cell swells and finally lyse.
c. Suppressor T cells: They suppress the function of above two T cells.
