Do most mammals have internal or external development?

Do most mammals have internal or external development?

Most mammals have both internal fertilization and internal development. The embryo develops inside a female organ called the uterus. Developing embryo obtains nutrients and oxygen and releases wastes through this structure, which is attached to the wall of the uterus.

Why do mammals use internal fertilization?

The offspring develops in the female and is born alive. This occurs in most mammals, some cartilaginous fish, and a few reptiles. Internal fertilization has the advantage of protecting the fertilized egg from dehydration on land. The embryo is isolated within the female, which limits predation on the young.

Are cats internal or external fertilization?

When we think about organisms mating, often we think of animals around us—humans, dogs, dragonflies, cats, lizards, or maybe birds. When these animals mate with each other, the egg and sperm meet inside the body, not outside in the air or water.

What is external fertilization called?

External fertilization is a mode of reproduction in which a male organism’s sperm fertilizes a female organism’s egg outside of the female’s body. The release of eggs and sperm into the water is known as spawning.

Why do fish use external 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.

What is internal and external reproduction?

Complete answer: Internal fertilization is the process when the syngamy (union of male and female gamete) occurs inside the female body after insemination using copulation. In contrast, External fertilization is the syngamy outside the female body, that is in the outer environment especially in water bodies.

Which type of egg is present in frog?

telolecithal eggs

Is frog egg Telolecithal?

The frog’s egg is telolecithal, meaning that there is a large amount of yolk concentrated at one pole, opposite to the concentration of cytoplasm and the location of the nucleus. The cleavages are holoblastic (i.e., total), and, after the second cleavage, they are unequal.

What is a butterfly egg?

Butterfly eggs are tiny, vary in color and may be round, cylindrical or oval. The female butterfly attaches the eggs to leaves or stems of plants that will also serve as a suitable food source for the larvae when they hatch. The larva, or caterpillar, that hatches from the egg is the second stage in the life cycle.

Can butterflies lay eggs without mating?

Its common for her to lay single eggs or clusters. They lay the eggs on host plants that are also a food source for the developing egg. If a female doesn’t mate immediately, she most likely never will. Not mating will prolong the female’s life, she will then die from natural causes or succumb to a predator attack.

Do butterflies die after laying eggs?

Do the butterflies die after they lay their eggs? A. No, they don’t. Adult monarchs live for anywhere from 2 to 6 weeks, and females lay eggs and males mate throughout most of this period.

How long is a butterfly pregnant for?

In March and April the eggs are laid on milkweed plants. They hatch into baby caterpillars, also called the larvae. It takes about four days for the eggs to hatch.

What season do butterflies lay eggs?

Eggs are laid on plants by the adult female butterfly. These plants will then become the food for the hatching caterpillars. Eggs can be laid from spring, summer or fall. This depends on the species of butterfly.

Which generation travels the longest in the migration?

super generation

Which butterfly stage eats the fastest?

Caterpillar This is the main feeding stage of the butterfly. Caterpillars eat almost constantly and grow very quickly, at an astonishing rate.