How does the acrosomal reaction during fertilization prevent polyspermy in animal development?
The acrosomal reaction releases enzymes from the sperm that help it penetrate the egg's protective coat, and triggers the cortical reaction in the egg, which depolarizes the membrane and prevents additional sperm from fusing with the egg, thus preventing polyspermy.
What is the role of cytoplasmic determinants in early embryonic development?
Cytoplasmic determinants are regulatory molecules unevenly distributed in the egg, leading to differences in gene expression among blastomeres after cleavage, which helps determine their developmental fate.
What is the purpose of the acrosomal reaction during fertilization in animal development?
The acrosomal reaction releases enzymes that help the sperm penetrate the egg's protective coat and triggers the cortical reaction, which prevents additional sperm from fusing with the egg.
How do cytoplasmic determinants influence early embryonic development?
Cytoplasmic determinants are regulatory molecules unevenly distributed in the egg, leading to differences in gene expression among blastomeres and helping determine their developmental fate.
What is the difference between indeterminate and determinate cleavage during early development?
Indeterminate cleavage produces cells that can each develop into a complete organism, while determinate cleavage produces cells that are already committed to specific developmental paths.
What are the three germ layers formed during gastrulation, and what does each give rise to?
The ectoderm forms nerves and skin, the mesoderm forms organs and muscles, and the endoderm forms the epithelial linings of the digestive tract and associated organs.
What is the function of the trophoblast in the blastocyst?
The trophoblast forms the outer layer of the blastocyst, gives rise to support structures like the placenta, and is not part of the developing organism itself.
How does the notochord contribute to neurulation in animal embryos?
The notochord induces the overlying ectoderm to form the neural plate, which folds to become the neural tube, eventually developing into the brain and spinal cord.
What is cell determination and how does it relate to differentiation?
Cell determination is the irreversible commitment of a cell to a specific developmental path, leading to differentiation into a particular cell type.
What is the role of induction during animal development?
Induction involves chemical signals from one group of cells influencing the developmental fate of neighboring cells, guiding their differentiation.