Answer:
The answer is <em><u>D.
</u></em>
Explanation:
Viruses can evade the processing and presentation of antigens, for example by interfering with the expression of MHC class I proteins, although this increases their susceptibility to be detected by natural killer cells (NK). However, some members of the herpesvirus, papillomavirus, retrovirus, poxvirus and flavivirus families have also developed strategies to escape the attack of NK cells and promote their survival, inhibiting cell apoptosis. Finally, some pathogens often change surface antigens frequently, as in the case of influenza viruses (orthomyxovirus).
The human immunodeficiency virus (HIV) affects CD4 + T cells and degrades the host's ability to counterattack with a strong cell-mediated immune response. There are so many tactics of immune evasion used by HIV, which have so far hindered the development of an effective vaccine.
Obligate parthenogenesis is the process in which organisms exclusively reproduce through asexual means. Many species have been shown to transition to obligate parthenogenesis over evolutionary time.
Explanation:
I'm not too sure but I would find the molar mass of nitrogen dioxide and then divide.
N - 14.01
O - 16.00
(14.01) + 2(16.00)
14 01 + 32.00 = 46.01
14.01 / 46.01 = 0.3044....
30.4%
32 / 46.01 = 0.6955....
69.6%
Answer:
B. RNA polymerase reaches the beginning of a gene
Answer:
A-Band
Explanation:
Sarcomere is the basic unit of skeletal muscle and shows various striations under the microscope.
Anisotropic band or A-Band is the portion of sarcomere that contains both the thick and thin filaments . A-Band appaers dark under the microscope. Thick filaments are consist of actin and thin filaments consists of myosin.
I-Band contains only thin filaments of myosin. H- zone contains only thick filaments and no thin filament. Sarcomere is the unit of a skeletal muscle. Synapse is the junction between two neurons.
Thus, the correct answer is option (A).
