In Guinea pigs, short hair is dominant and long hair is recessive. A heterozygous male is crossed with a long-haired female. They have a litter
of six babies. Answer the following: (a) What letters will you use for this
cross and what will they represent? (b) What is the parent cross? (c) What
are the possible genotypes of the offspring, and what percent will carry
each genotype? (d) If they have six babies, how many would you expect to
have long hair? short hair? *

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.