Pollination and Ripening flashcards

I. Pollination/Abscission

Why is abscission important

  • stop attracting insects

II. Double fertilization

a. one sperm fertilizes the egg to make zygote

b. other sperm fertilizes central cell (in middle of gametophyte) to make endosperm

AFTER fertilization, embryo starts maturing inside

  • endosperm not completely digested yet

  • an embryo is mature when it has consumed the endosperm and the embryo has filled the seed

    • the mature seed will be the signal to start the fruit ripening

II. Ripening

  • ripening begins with ovary enlarging

  • sucrose enters the fruit and breaks down glucose (ATP) and fructose (sweetener)

  • forms anthocyanins/carotenoids to attract

  • other fruits can dry/split to disperse seeds

  • other fruits can form hooks for animal dispersal

  • explosive fruits exist, shoot their seeds out

  • some have wings for wind dispersal

    • tumbleweeds, dandelions and cotton use wind dispersal

  • some fruits can harden and trap air for floatation

    • ex: coconut - designed to float on ocean until it lands on land

    • coco de mer - largest fruit in the world, found east of africa in indian ocean