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.
4 Chapter 1 Double Fertilization â A Deï¬ ning Feature of Flowering Plants. one of them fused with the nucleus of the egg cell, the other fused with the polar fusion nucleus (at that time known as the deï¬nitive nucleus) ï¬oating in the central cell, initiating a second fertilization event (Nawaschin 1898, 1899).