What is the rounded upper end of the humerus, which fits like a ball into the glenoid cavity of the scapula?

Which statements correspond to cellular respiration? co2 diffuses passively into the cell. co2 diffuses passively out of the cell. co2 must be pumped out of the cell. o2 diffuses passively when produced inside the cell. o2 diffuses passively when converted to co2. o2 is pumped in and forces co2 out.

Chinese privet is a plant that is native to china. over 150 years ago, chinese privet was introduced to the united states as a fast-growing shrub that serves as an excellent privacy hedge. with no natural herbivore, chinese privet quickly established itself and spread in natural areas throughout the southeast and eastern seaboard of the united states. its dominance in these areas has jeopardized the survival of native plant species. chinese privet provides evidence that introducing non-native organisms can cause environmental damage integrated pest management strategies will not decrease chinese privet populations american gardeners can easily control the spread of chinese privet non-native plant species have type i survivorship curves

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?