Answer:
2
Explanation:
The two DNA strands intertwine around each other to form a double helix.
DOUBLE HELIX describes the structure of the DNA
The right answer is blastocyst.
The blastocystic Stage of embryo development is characterized by the formation in the center of the morula (embryonic cell group) of a cavity isolated from the external environment: the blastocoele.
In embryonic development, this step precedes gastrulation.
Blastocysts are indeed composed of a hundred cells; they have the shape of a hollow sphere at the bottom of which is the mound of the "embryonic bud" from which the embryonic stem cells are derived.
To move substances against a concentration or electrochemical gradient, the cell must utilize energy in the form of ATP during active transport. Primary active transport, which is directly dependent on ATP, moves ions across a membrane and creates a difference in charge across that membrane.
