2. What made scientists think that the change in Tibetans was caused by natural selection A. because the gene for adapting to high altitude is found in their Han relatives
B. because the gene for adapting to high altitude is NOT found in their Han relatives
C. because the gene for adapting to high altitude is NOT in both of them

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

This is what i did 45-5=4040÷4=10so there are 10 white marbles but am not sure is just a question that am not sure

Writing, you can revisit previous parts of the lesson by returning to the course map. be sure to refer to the lab’s student guide, which you can find on the first page of the lab experiment activity

All of them are man made