25) when does the synaptonemal complex disappear?
a) late prophase of meiosis i
b) during fertilization or fusion of gametes
c) early anaphase of meiosis i
d) mid-prophase of meiosis ii
e) late metaphase of meiosis ii

this is a good question! i'll do some research and come back when i have the answer!

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

here is the answer

water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. weathering is the breaking down or dissolving of rocks and minerals on earths surface. once a rock has been broken down, a process called erosion transports the bits of rock and minerals away.