Which of the following is a possible consequence of ozone layer depletion on living organisms? a. increased exposure to ground-level ozone b. decreased levels of ultraviolet radiation in the troposphere c. increased levels of ultraviolet radiation absorption in the stratosphere d. none of the above

What type of organism is a one-celled organism that functions as a single unit? a. bi-celled b. single-celled c. pre-celled d. multi-celled

The picture showed normal blood cells which are around and sickle cells which appear much longer people with sickle-cell suffer from the sickle cell anemia which is inherited diseaseit is caused by a change in gene responsible for production of hemo goblin this type of change is known as an

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?