Front

What does the pha-4 gene control in development?

Back

The pha-4 gene controls the formation of the pharynx.

Front

What is the polar lobe?

Back

The polar lobe contains a high concentration of morphogenetic determinants essential for the development of specific tissues and organs.

Front

Which blastomere in molluscan development is specified to develop into specific tissues regardless of its environment?

Back

The D blastomere receives the contents of the polar lobe and is autonomously specified.

Front

What is the role of the P4 cell during gastrulation?

Back

The P4 cell is a germline precursor cell that moves inward during gastrulation.

Front

What is spiral cleavage in mollusks?

Back

Spiral cleavage is a modification of the typical pattern of molluscan development, particularly observed in unionid clams.

Front

Define morphogenetic determinants.

Back

Morphogenetic determinants are substances that influence the development of specific tissues and organs during embryogenesis.

Front

What is the significance of the D blastomere in molluscan development?

Back

The D blastomere is significant because it autonomously develops into specific tissues, independent of environmental factors.

Front

Explain the process of gastrulation.

Back

Gastrulation is a phase in embryonic development where the single-layered blastula reorganizes into a multilayered structure, forming the germ layers.

Front

What are germline precursor cells?

Back

Germline precursor cells are cells that give rise to the gametes (sperm and eggs) in an organism.

Front

What is the function of the pharynx in organisms?

Back

The pharynx serves as a passageway for food and air, playing a crucial role in the digestive and respiratory systems.