Answer:
Macrophages are part of your innate immune system, which is antigen-independent and does not require activation.
Explanation:
Macrophages phagocytize (internalize) all non-self pathogens it encounters. These do their job without activation. Other cells in the innate immune system include basophils, neutrophils, eosinophils (these cells are polymorphonuclear leukocytes), mast cells, and dendritic cells, which act as the bridge between your innate and adaptive immune system.
All of the other entities listed above are part of your adaptive immune system. The adaptive immune system is antigen-dependent and requires activation. This section of your immune system responds differently to different pathogens, and has the bonus of having immunologic memory, the ability to remember pathogens after infection and respond much quicker upon secondary and tertiary encounters.
Note: All lymphocyte types begin as naïve cells, which then differentiate into their fully matured form upon activation.
Helper T cells are a type of CD4+ T cell that has the job of activating B and T lymphocytes. There are two different types of T helper cells: Th1 and Th2. Th1 cells secrete the cytokine interferon-gamma (IFNγ), and is primarily involved with the stimulation and activation of cytotoxic T cells, while Th2 cells secrete a variety of cytokines and are responsible for activating and assisting with B cells to make antibodies. To make a long story short, Th cells interact with APC (Antigen Presenting Cells), specifically their Class II MHC (a group of genes that present exogenous proteins). The Th cells then proliferate and gain the ability to activate these APC cells and provide the necessary signals to activate B and T cells and make them proliferate and do their specific function.
Theater to your question is A
Answer: EXERGONIC; ENDERGONIC
Explanation:
An Exergonic reaction is one that occurs spontaneously, with the release of high amount of energy usually in form of ATP. a good example of this is the oxidation of glucose (glycolysis) in the Human body.
Whereas an energetic reaction is one that will ONLY occur in the supply of energy. A good example is biosynthethic reaction such as
- formation of glycogen (glycogenesis)
- formation of lipids etc
Answer:
In addition to biology, evidence drawn from many different disciplines, including chemistry, geology, and mathematics, supports models of the origin of life on Earth. In order to determine when the first forms of life likely formed, the rate of radioactive decay can be used to determine the age of the oldest rocks (see optional problems C and D, below) exposed on Earth’s surface. These are found to be approximately 3.5 billion years old. The age of rocks can be correlated to fossils of the earliest forms of life. A. The graph compares times of divergence from the last common ancestor based on the fossil record with a "molecular time" constructed by comparing sequences of conserved proteins to determine a mutation rate (after Hedges and Kumar, Trends in Genetics, 2003). Explain how such a molecular clock could be refined to infer time or the evolution of prokaryotes. B. Using a molecular clock constructed from 32 conserved proteins, Hedges and colleagues (Battistuzzi et al., BMC Evol. Biol. 2004) estimated the times during which key biological processes evolved. A diagram based on their work is shown. Connect the time of the origin of life inferred from this diagram with the age of the oldest fossil stromatolites and the age of the oldest exposed rock to show how evidence from different scientific disciplines provides support for the concept of evolution. Evaluate the legitimacy of claims drawn from these different disciplines (biology, geology, and mathematics) regarding the origin of life on Earth. The oldest known rocks are exposed at three locations: Greenland, Australia, and Swaziland. The following application of mathematical methods provides essential evidence of the minimum age of Earth.
Explanation:
