there is no clear evidence about plants evolving in the desert, or fossils of any kind of cactus despite their distribution over a large area. But, scientists are of the opinion that they acquired specific attributes millions of years ago, as a response to the vastly changing climate and conditions.
-Desert plant root system
A typical desert plant has a deep root system, which is a specific physical mechanism. As the roots grow deep down the soil, they absorb soil water, which is then transported to the upper portions of the plant.
-Desert plant leaves
Bear small foliage with waxy surface to minimize transpiration (loss of water through stomatal pores), which in turn, helps to conserve water.
The membrane is selectively permeable because substances do not cross it indiscriminately. Some molecules, such as hydrocarbons and oxygen can cross the membrane. Many large molecules (such as glucose and other sugars) cannot. Water can pass through between the lipids.
tRNA-precursors were smaller than the modern tRNA and their primary function was to participate in the formation of new structures by joining two or more RNA molecules.
The adaptor hypothesis is the explanation of how information could be extracted from a nucleic acid into a string of amino acids in a specific sequence. The proposed explanation involved recognition between the adaptor (today tRNA) and the template nucleic acid .
The Chesapeake bay’s salinity is the highest where seawater from the Atlanta ocean enters. As you head north in the bay, salinity gradually decreases