Ontogeny. (1987)

Spin the hoop with figures of a person, birds and animals inside (animation).

Schematic demonstration of the phases of ontogenesis (animation).

Meadow grass and flowers.

The process of fertilization, the connection of male and female germ cells.

The penetration of the sperm into the egg, the connection of the X and Y chromosomes (animation).

Thickening of the egg shell.

Combining the nuclear material of an egg and a sperm (animation).

Embryo formation-zygotes, embryo cell division (animation).

Division of fragmentation, the division of the embryo into two daughter cells (animation).

Fish prepare the place of laying eggs, the female lays eggs.

The male fertilizes the eggs.

Newborn fry.

African spur frog in the aquarium.

Sexual intercourse of male and female spur frogs.

Fertilized eggs laid by the female in the water for further development.

The process of crushing a frog egg and forming a multicellular embryo, complete separation of the egg and the formation of a blastula.

Conditional incision and blastula device (animation).

The appearance of the ectoderm cells during gastrulation of the egg (animation).

Mesoderm formation (animation).

Formation of the surface of the embryo of the primary mouth - blastopore (animation).

Diagram of the movement of germ leaves during gastrulation.

A dark blastopore spot on the living material.

The process of neurulation and the formation of the neural tube, with the formation of the rudiment of the spinal cord on a living example.

The process of brain development in the embryo (animation).

Stretching of the embryo in length, the occurrence of spontaneous muscle contractions.

Tadpoles at the bottom of the aquarium.

Diagram of the formation of the ectoderm of the integumentary tissues, the nervous system, and the sensory organs (animation).

The organs of sight and smell of the frog.

Scheme of development from the endoderm of the digestive system and lungs (animation).

Diagram of the formation of the bones of the skeleton, muscles and circulatory system of the frog from the mesoderm (animation).

Fish and spur frogs in the aquarium.

Stages of ontogenesis.

Tadpoles in the stage of postembryonic development.

Tadpoles in search of food.

Types of tadpoles.

Development of limbs in tadpoles.

Turning a tadpole into a frog.

Young frogs during the maturation of sexual products.

Stages of postembryonic development of frogs (animation).

View of the edge of the spring forest, the bear crosses the clearing.

The bear cub is getting out of the den.

A bear cub with a bear in the forest.

A beetle on a flower.

Stems and leaves of meadow grass.