If the gas exchange takes place through the skin, that is called:

Fish, molluscs and crustaceans have:

If air enters the body through small openings located on the abdomen and moves into a network which carry air directly to the cells, that is:

Terrestrial vertebrates breathe thanks to:

The circulatory system in which the circulating fluid can move in and out of the vessels and bathes the tissues of the body is called:

Annelids, cephalopods and vertebrates have a circulatory system which is:

In annelids and vertebrates, the circulating fluid of the circulatory system is called:

In molluscs and arthropods, the circulating fluid of the circulatory system is called:

In echinoderms, the circulating fluid of the circulatory system is called:

Specialized, sensory cells that receive stimuli from the external or internal environment are:

Receptors that detect light are called:

Receptors that detect sound are called:

Receptors that detect smell and taste are called:

Some snakes can detect heat of their preys with their:

The organ that detects sea currents in fish is called:

The effectors are:

The type of reproduction in which one progenitor produces a new genetically identical living thing is:

The type of reproduction in which two progenitors produce a new living thing similar to both of them is:

If a new organism grows from a fragment of the progenitor, that is called:

The reproductive cells are called:

When an individual has male and female gonads at the same time, it is called:

Almost all animals have separated sexes that can be distinguished by physical differences like size, shape or colour. We call that:

When the union of gametes happens outside the body of the female, it is:

When the union of gametes happens inside the body of the female, it is:

Terrestrial animals, aquatic mammals and sharks have:

Most aquatic animals and amphibians have:

If the embryo develops inside an egg outside the female body, that animal is:

If the embryo develops inside an egg inside the female body, that animal is:

If the embryo develops inside the female body, that animal is:

When the offspring are similar in appearance to the adult and the development simply involves a growth process, that is:

When the young or larvae go to profound changes until they become adults, that is:

If the young (larvae) go to profound changes until they become adults, these changes make up the process called: