More deaths than poachers, deforestation or pollution. An estimated 1.3 million animals die every day after being struck by cars and trucks in Brazil, according to a recent study by Centro Brasileiro de Estudos em Ecologia de Estradas. That's 475 million animals every year in one country alone: about 15 animals every second. Over the duration of the study, the team documented the deaths of 165 different species: 10 amphibian, 21 reptile, 63 avian and 71 mammal.
Double fertilization in Arabidopsis. Double fertilization is a complex fertilization mechanism of flowering plants (angiosperms). This process involves the joining of a female gametophyte (megagametophyte, also called the embryo sac) with two male gametes (sperm). It begins when a pollen grain adheres to the stigma of the carpel, the female reproductive structure of a flower.
Plant Reproductive Structures. Plant sexual reproduction relies on stamens, which are the male parts, and pistils, which are the female parts. Stamens contribute the male genetic material in the form of pollen, which is produced from anthers that are on the terminal ends of stalks called filaments.ome plants donât form distinct petals and sepals, but they have one undifferentiated whorl comprised of structures called tepals. Petals, sepals, stamens and pistils are not formed on all flowers, but when they do the flower is said to be âcomplete.â.