Ans.
Different barriers present in the body prevent entry of disease causing agents or pathogens from entering into body and provide protection against them. These barriers include various physical, chemical, and biological barriers.
Physical barrier include skin and coughing and sneezing. Skin provides first line of defense by preventing entry of pathogens, and coughing and sneezing that expels harmful agents out of the body.
Chemical barriers include lysozyme, acids, and oil secretion. Lysozyme is an enzyme that kills bacteria by targeting their cell wall, while oil and acid prevent microbial growth by providing non-favorable environment for them.
Biological barriers include phagocytes and Langerhans cells. Phagocytes are immune cells that engulf and destroy pathogens and Langerhans cells are antigen-presenting cells that help in elimination of pathogens.
Answer:
Part-A will lead toward the head development of Drosophila.
Explanation:
A morphogen is a substance that governs the pattern of tissue development in the process of morphogenesis or pattern formation, Pattern formation is one of the core processes in the development of Drosophila's body. Bicoid was the first protein demonstrated to act as a morphogen. Bicoid is a gene whose protein concentration gradient patterns the anterior-posterior (A-P) axis during Drosophila embryogenesis. Although Bicoid is important for the development of Drosophila's head. Bicoid concentration is high in the anterior side or in part-A of the Drosophila that will become the head. Bicoid concentration is low at the posterior side or part-E of the Drosophila that will become the tail.
Answer:
True (although question is not clear enough)
Explanation:
Adaptive radiation occurs when <u>organisms evolve from the same ancestor. This process takes place as a result of environmental changes or when they are introduced to or colonize a new environment.</u> These changes become challenges that force these individuals to adapt to these new conditions.
Therefore, <u>this results into a faster evolution that creates different new forms</u> that possess a diversity of variations adapted to their new feeding habits, environment, and behavioral needs.
<em>One of the most famous examples of adaptive radiation is the formation of new forms of Galapagos finches.</em> These striking finches, which arose from a common ancestor, evolved different beak sizes and shapes that were especially adapted to different types of food. As different as they may appear, they are closely related!