The presence of hydrogen bond is one factor that explains the fact that ice floats over water because it has less density.
Due to this, rivers and lakes freeze from the surface whereas it is in liquid state at the bottom which allows the sea animals to survive even in colder temperatures.
Water makes up at least 70% of earth and 65% of our bodies and this property of water is essential for our lives as it maintains the survival.
Answer:
Thymine
Explanation:
Uracil is the nitrogenous base present only in RNA, but not in DNA. ... DNA have thymine, guanine, adenine and cytosine. Thymine is replaced by uracil in RNA.
<span>Lactase persistence, the ability to digest the milk sugar lactose in adulthood, is highly associated with a T allele situated 13,910 bp upstream from the actual lactase gene in Europeans. The frequency of this allele rose rapidly in Europe after transition from hunter–gatherer to agriculturalist lifestyles and the introduction of milkable domestic species from Anatolia some 8000 years ago. Here we first introduce the archaeological and historic background of early farming life in Europe, then summarize what is known of the physiological and genetic mechanisms of lactase persistence. Finally, we compile the evidence for a co-evolutionary process between dairying culture and lactase persistence. We describe the different hypotheses on how this allele spread over Europe and the main evolutionary forces shaping this process. We also summarize three different computer simulation approaches, which offer a means of developing a coherent and integrated understanding of the process of spread of lactase persistence and dairying.</span>
