Endosperm cells in a corn grain are a. haploid. Formation of shoots from callus needs a. high auxin concentration and low cytokinin concentration. The function of a fleshy fruit is to a. feed the new embryo. The early atmosphere on earth contained which of the following gases. Rising oxygen levels is associated with the appearance of multicellular life about 1 billion years ago.
Some forms of life can exist without oxygen e.
The ability of some organisms to use solar energy to split water into hydrogen and molecular oxygen contributed to rising oxygen levels. As new bacterial life forms evolved on early earth, which had the greatest potential for widespread success in the most habitats.