LIFE SCIENCE

Detailed explanation-1: -The urogenital system arises from intermediate mesoderm which forms a urogenital ridge on either side of the aorta. The urogenital ridge develops into three sets of tubular nephric structures (from head to tail): the pronephros, the mesonephros, and the metanephros.

Detailed explanation-2: -The inner cell mass is also known as the embryoblast and this mass of cells will go on to form the embryo. At this stage of development, illustrated in Figure 24.25 the inner cell mass consists of embryonic stem cells that will differentiate into the different cell types needed by the organism.

Detailed explanation-3: -The development of the bladder begins during week four when the urogenital septum divides the cloaca into two parts, the rectum posteriorly and the urogenital sinus anteriorly. The urogenital sinus will continue to grow to form the bladder, with the inferior end forming the urethra.