Answer:
Walking alone late one night, you are startled by a moving shadow that you glimpse out of the corner of your eye. The sympathetic division of the autonomic nervous system is activated. When you realize it is just the neighbor’s pet, the parasympathetic division lessens your physiological arousal.
Answer:
D.
Explanation:
Viruses are oftentimes short lasted and disappear quickly.
Answer:
d.The wing-assisted incline running theory postulates that wings were initially used to maintain balance while climbing up slopes.
Explanation:
Two theories were given to explain the origin of avian flight. The top-down theory suggested that the birds' ancestors were tree dwelling species. They took help of wings to glide from tree to tree in order to avoid predator or catch prey. The bottom up theory suggested that the birds' ancestors were ground dwelling species. They took help of wings to maintain a balance and provide a lift for efficient running.
Wing-assisted incline running was a mixture of both the above theories and gave a balanced view point. According to it, birds' ancestors used wings to maintain a balance while running up inclined slopes. The wings helped them to save energy while scaling slopes and eventually a flight mechanism was also developed.
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.
Answer:
Cell division is a process that makes our skin, tissues, muscles, sex cells etc. It is the building block of our body.
Explanation:
When parents cells ahs been divided into two or more than two daughter cells then it is called division of cells. The division of cells occur as a larger cell. When we talk about eukaryotic cells, these cells divided into two distinct types of the cells, the vegetative cells.
The daughter cells are the identical to the parents cells genetically. There are two types of division such as mitosis and meiosis. When parents cells divides in daughter cells and daughter cells divided further, this process called the cells cycle. The mitosis cell division occur interphase. Meiosis cell division occur in two phase meiosis I and meiosis II.
