A biology student caught andtagged 50trout in a small lake. After two weeks, the student caught another 40 trout and foundthat 4 of them were tagged— these 4 had beenin theoriginal sample and were caught a secondtime. Whatis the best estimate of the populationof trout in the lake? What might have contributed to the low numberof tagged trout caughtthe second time? How could the student reducethis factor? please someone help me with this question.

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?

This is one of the five kingdoms in the older biological succession. organisms in this kingdom are prokaryotic.

After a group of researchers conducts a new experiment that has never been conducted before, what is the best way for other scientists to make sure that the data is real