Why does our blood pressure generally go up as we age?

Which of the following sex and generation combinations directly produces the pollen tube of angiosperms? a) male gametophyteb) female gametophytec) male sporophyted) female sporophyte

~~16. while watching a special on animals, brianna discovers that hares tend to lose heat through their ears. based on this and what is known about surface-to-volume ratios, propose an explanation as to why hares that live in hot climates (such as the desert) have large, extended ears

Wich level of organization includes all the other levels or organizations