Question

Which one of the following characteristics is common both in humans and adult frogs?
A. Internal fertilization
B. Nucleated RBCs
C. Ureotelic mode of excretion
D. Four chambered heart

Answer 1

Hint: Frogs and humans, thus belonging to two separate groups within the animal kingdom. The same essential organs are shared by frogs and humans. They both have lungs, kidneys, stomach, heart, brain etc. There are testicles and ovaries for both males and females of each species. Their organ structure is identical in general, but frogs have significantly less complex anatomies.

Complete answer:
Internal fertilization- the fertilization that occurs in humans is internal fertilization, however, In the majority of frog species, fertilisation is external. As the female frog releases them, the male frog grabs the female's back and fertilises the eggs. Around a thousand eggs are normally laid by Rana pipiens, while the bullfrog, Rana catesbiana, may lay more eggs. In pond vegetation, some species lay their eggs, and the jelly adheres to the plants and anchors the eggs. Other species float their eggs without any assistance in the centre of the pond.
Nucleated RBCs- Those from amphibians, such as frogs, contain a DNA-bearing nucleus which is evident in the centre of the cell, unlike traditional mammalian red blood cells. The amphibian circulatory system is fairly uncommon, with three chambers, two atria, and a single ventricle in their hearts.
Ureotelic mode of excretion- Urea is excreted in some mammals and amphibians as the result of metabolic waste. These species are known as ureotelic. Ammonia that is produced in these species is transformed into urea in the liver of animals and released back into the blood. As we remove the urea through urine, humans are ureotelic. Most species turn toxic urea into less toxic urea and, for example, excrete adult frogs.
Four chambered heart- The heart is made up of four chambers from which blood flows. In the right atrium, blood joins and travels into the right ventricle. The blood is pumped to the lungs by the right ventricle where it is oxygenated. The pulmonary veins that enter the left atrium carry the oxygenated blood back to the heart, while the heart of the frog has three chambers, one ventricle and two atria.

Hence, the correct answer is (C).

Note:
Frogs do not have many vertebrae and do not have a pelvis. They also have structures in the human skeleton that are not found, which is the urostyle. One reason frogs are always selected to be dissected is that a clear description of the organ systems of a complex living thing is given by their bodies. The organs that are found in a frog and the way they are set out in the body are sufficiently close to humans to provide students with insight into how their bodies function.