Answer:
During the Devonian period which occurs 375 million years ago, gills are present in the fossil of tetrapods.
Explanation:
Gills present in tetrapods which able the marine animals to breathe inside water but with the passage of time the sac which is present around the gills convert into lungs and these tetrapods are able to live on the land. Examples of tetrapods are frog, lion, birds and salamander etc.
Lost phosphorus is actually recycled through the processes of mineralization, reabsorption, dissolving, and precipitation.
The answer is cross-pollination, by using parents that had different traits.
Gregor Mendel researched pea plants and he <span>established the principles of heredity. To explain his experiments and discoveries, he invented terms dominant and recessive in reference to traits. In his experiments, he used cross pollination which includes the crossing of parents with different traits. For example, he crossed a plant with green peas and a plant with yellow peas (two different traits) and studied how these traits are inherited to the next generation.</span>
I) Alleles is the alternative form of a gene or in other terms the variant form of a gene. If there are two alleles at a locus p and q are used to represent their frequencies. Frequencies of all alleles in a population will add up to 1.
Therefore, in this case if red allele CW is p=0.7, then the frequency of the white allele in this population (q) is 0.3.
ii) From the punnet square the expected genotypes frequencies in the offspring generation will be 0.49 CRCR (red flowers, o.42 CRCW (pink flowers) and 0.09 CWCW (white flowers).
Answer;
-Distal end
Explanation;
-The part of the esophagus that is farthest from its beginning at the throat is the distal end.
-The esophagus is a muscular tube connecting the throat with the stomach. It is about 8 inches long, and is lined by moist pink tissue called mucosa.
-Both ends of the esophagus are closed off by muscular constrictions known as sphincters; at the anterior, or upper, end is the upper esophageal sphincter, and at the distal, or lower, end is the lower esophageal sphincter.
