Answer:
Meotic cell division (mitosis)
Answer:
The offspring of organisms that is reproduce through sexually are not genetically identical to their parents because the offspring contains genes from two parents.
Explanation:
Identical offspring is only formed when offspring is produced from one parent through asexual reproduction such as building, binary fission and fragmentation. In sexual reproduction, offspring is produced by the mating of two organisms i. e. male and female organism. That's why genes of offspring are different from their parents and offspring is not identical to parents.
Carbon is released into the atmosphere only during the burning of fossil fuels
Explanation:
During the process of fuel burning, carbon is released in the atmosphere. The human invented power plants, factories, cars and other vehicles releases carbon in the form of carbon di-oxide in atmosphere.
However, the cellular respiration is similar to that of fuel burning as it is too a combustion process. But the carbon produced in this process fuels the inner cellular activities rather than releasing it in the atmosphere.
Answer:
TNF-alpha is expressed as a homotrimer that exerts its activities through binding to two types of receptors: TNFR1 and TNFR2, which are transmembrane glycoproteins characterized by having an extracellular domain with 4 cysteine-rich domains (CRD 1-4) , each with 3 cysteinecysteine disulfide bonds.
Explanation:
TNF-alpha (Tumor Necrosis Factor), which has the characteristic of being a paracrine signaling ligand, is a pleiotropic cytokine that functions as a mediator of immune regulation, the inflammatory response and apoptosis in some cell types. Receptors in this family are involved, with some exceptions, in juxtacrine signaling; that is, both the ligand and the receptor are membrane proteins with extracellular domains through which signaling is established. The cellular responses promoted by TNF are initiated by its interaction with two different types of cell receptors, the type I receptor (55 kDa) and the type II receptor (75 kDa). Both types of receptors are part of the TNF receptor family, members of which include Fas antigen (apoptosis inducer, also called Apo-1 or CD95), CD27 (T-cell activation antigen), CD30 (lymphoma marker Hodgkin) and CD40 (B-cell antigen), which share the characteristic of cysteine-rich sequences in their extracellular domains. This family of cytokines generate cellular responses that include differentiation, proliferation, activation of NFκB and cell death, promoting the aggregation of receptor monomers, that is, they have a transmembrane domain that participates in the solubilization of the receptor and a domain of intracellular death that is involved in signal transduction. The binding of TNF to TNF-R1 induces a signaling cascade through its intracellular death domain, which subsequently leads to the activation of complex I (or inflammatory) of NFkB and proceeds to the transcription of anti-apoptotic genes, pro- inflammatory diseases and apoptosis complex II (caspases).
