What is a hormone? multiple choice: o a chemical released from a nerve cell that affects nearby cells across a synapse o a chemical released from an endocrine gland that affects target cells without entering the bloodstream o a chemical found in the blood that catalyzes the destruction of ingested toxins and foreign substances o a chemical excreted from sweat gland that signals other individuals about the physiological status of the body o a chemical regulator secreted from an endocrine gland that travels through the bloodstream to affect target cells

Which of the following describes how binary fission and mitosis are similar? a)they are both used for growth or repair b)they both break down membrane-bound nuclei c)both invoke the replication of a single stand of dna d)both replicate genetic material

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?

Which individual below would be considered heterozygous? a. dd b. dd c. dd