Answer:
Superior vena cava
Explanation:
Of the two vena cava, the superior vena cava is the large vein without valves that is responsible for conveying de-oxygenated blood from the upper extremities and body (neck, chest, arm and head) above the diaphragm to the right artrium.
Although the superior vena cava is a large vein, it also short; it is about 2 cm wide and 7 cm long.
When there is an obstruction of the superior vena cava, it can result to the enlargement of the veins and could lead to chest pain and breathlessness.
The process of constructing an mRNA molecule from DNA is know a transcription. The bases pairing rules ensure that the DNA code is conserved in the sequence in the mRNA
An organic compound consists of carbon...
The correct answer is B. The parents are heterozygous with polka-dot tails, so they both have Pp genotype. The combination of their genotypes (Pp x Pp) could produce 4 genotypes PP, Pp, Pp and pp. Therefore, there is 25% chance for a PP genotype, 25% for a pp genotype and 50% for a Pp genotype. The PP and Pp genotypes produce a polka-dot tail phenotype and the pp genotype produces a solid coloured tail phenotype. In conclusion, there is 75% chance for a polka-dot tail (25% for a PP + 50% for a Pp) and a 25% for a solid coloured tail phenotype (25% for a pp).