Biology Questions

Cretinism is a disease caused by hypothyroidism (less thyroxine formation) . The symptoms of the disease are retardation of mental, physical and sexual developments. potbelly, protruding tongue, dry skin etc are also indicative of this disease.

Water is the important nutrient all organisms need. Humans has almost 60% of their body weight is water. Some organisms have 90% of their body weight is of water.

If you were to produce a protein in bacterial cloning systems, you would not get the same post transcriptional and post translational modifications because the prokaryotic and eukaryotic systems work differently on the modifications.

Thus human recombinant protein genes are usually cloned in yeast cells. Also since they have a short generation time, they can be easily culture.

In flowering plants one sperm nucleus fertilizes the egg and the other sperm nucleus fuses with two other nuclei found within the ovule, thus forming triploid endosperm.

Hence, double fertilization is unique to flowering plants.

A tetrad is best described by Four chromatids. It is formed from two homologous chromosomes, each consisting of two chromatids in the first stage of meiosis called prophase1.