What is the purpose of the proper handeling of experimental subjects

Which box will not accelerate? 4 newtons 4 newtons 4 newtons 25 kg 4 newtons 15 newtons 10 kg 30 newtons 40 newtons 50 kg 30 newtons 30 newtons

The table lists the observations students made about four specimens under a microscope. based on these observations, what specimens did the students examine? animal plant virus prokaryote cell membrane present ribosomes present lysosomes present nuclear membrane present cell wall present ribosomes present nuclear membrane absent cell wall present ribosomes present nucleus present large vacuole present reproduces inside of a cell nucleus absent rna present 2019 edmentum all rights reserved intl

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?