Although meat lacks cellwalls, repeated freezing and thawing
produces the bad taste offreezer burn. what is the main organelle
involved in thisautodigestion?

Lysosome

Explanation:

Freezer burn occurs due to the sublimation of ice in unprotected meat rich in muscles during long-frozen storage. It appears after thawing. The ice crystals rupture the lysosomes which in turn contain hydrolyzing enzymes.

Leakage of the hydrolytic lysosomal enzyme causes freezer burn and affects the appearance of the frozen meat. The hydrolytic enzymes of lysosomes partially digest the cells which in turn impart bad flavor to the stored food.

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation:

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.