Which vertebrates fertilization exclusively internal

May have lungs, or gills, and may use skin as a respiratory surface. No urinary bladder, females with one ovary, no teeth. Which are the most abundant and diverse of the extant vertebrates? What is the single unique characteristic that distinguishes extant birds from other extant vertebrates? Arrange the following taxonomic terms from most inclusive i. Which of these hominin traits seems to have occurred before the others? This E-mail is already registered as a Premium Member with us.

Kindly login to access the content at no cost. This E-mail is already registered with us. Not my Question Bookmark. The trigger for egg and sperm release spawning causes the egg and sperm to be placed in a small area, enhancing the possibility of fertilization.

External fertilization in an aquatic environment protects the eggs from drying out. Broadcast spawning can result in a greater mixture of the genes within a group, leading to higher genetic diversity and a greater chance of species survival in a hostile environment. For sessile aquatic organisms like sponges, broadcast spawning is the only mechanism for fertilization and colonization of new environments. The presence of the fertilized eggs and developing young in the water provides opportunities for predation resulting in a loss of offspring.

Therefore, millions of eggs must be produced by individuals, and the offspring produced through this method must mature rapidly. The survival rate of eggs produced through broadcast spawning is low. Internal fertilization occurs most often in land-based animals, although some aquatic animals also use this method. There are three ways that offspring are produced following internal fertilization. This occurs in most bony fish, many reptiles, some cartilaginous fish, most amphibians, two mammals, and all birds.

Reptiles and insects produce leathery eggs, while birds and turtles produce eggs with high concentrations of calcium carbonate in the shell, making them hard. Chicken eggs are an example of this second type.

Designed using Magazine Hoot. Powered by WordPress. Skip to content. Correct Answer Below Reveal the answer to this question whenever you are ready.