Stages of Embryonic Development: A Comprehensive Overview
Stages of Embryonic Development
Fertilization
Fertilization is the fusion of an egg with a spermatozoon. When the male gamete reaches the female gamete, the latter undergoes a series of electrical and chemical reactions that prevent the entry of more than one male cell.
Segmentation
Once the pronucleus of the egg is functioning with the sperm pronucleus, the egg begins to undergo a series of mitotic cell divisions. Each of these cells is called a blastomere, and the resulting mass of cells is called
Read MoreUnderstanding Cell Division: Mitosis and Meiosis
Cell Division: Mitosis and Meiosis
Mitosis
Prometaphase
Prometaphase occurs after the fragmentation of the nuclear envelope, leading to the mixing of the cytoplasm and nucleoplasm. Chromosomes condense and remain within the cell. Kinetochores, protein complexes that attach to microtubules, develop on the centromeres. Microtubules pull the chromosomes, resulting in a chaotic movement known as the “dance of the chromosomes.”
Metaphase
During metaphase, the centromeres align at the equatorial plate of the
Read MoreCell Biology: Structure, Function, and Processes
Classification of Proteins
Holoproteins
Filamentous, insoluble in H2O, polypeptides arranged in only one dimension as parallel fibers.
- Collagen: Found in connective tissue, cartilage, and bone, provides resistance to stretch.
- Keratin: Synthesized and stored in the cells of the epidermis, forms hair.
- Elastin: Flexible, fibrous proteins found in tendons and blood vessels, allows them to recover their shape after stretching.
- Myosins: Actively involved in muscle contraction.
Globular Proteins
Complex globular
Read MoreProkaryotic vs. Eukaryotic Cells: Structure, Function, and Differences
Prokaryotic vs. Eukaryotic Cells
Prokaryotic Cells
Prokaryotes are evolutionarily ancient life forms that existed billions of years before eukaryotic cells. Even with the evolution of more complex cells, prokaryotes like bacteria and Archaea remain supremely successful. They lack a nucleus.
Eukaryotic Cells
Eukaryotic cells are more complex, evolving from prokaryote-like predecessors. Most familiar living things, including animals, plants, fungi, and protists, are composed of eukaryotic cells. Eukaryotic
Read MoreWhite & Gray Matter, CNS, ANS, Hormones & Reflex Arc
Tema15 1_Explica the difference between white matter and gray matter and the generic function of each. In the CNS can distinguish the white matter and gray matter. The white matter consists of axons covered with myelin, which are the nerve pathways, and the gray matter, an accumulation of cell bodies and dendrites, essentially, that are the hubs and integración.E2_Describe elementos.La the synapse and synapse is the area of functional communication between two distinguished neuronas.En synapses:
Read MoreGametogenesis: Spermatogenesis vs. Oogenesis
Gametogenesis: Formation of Gametes
Gametogenesis is the process of gamete formation through meiosis from germ cells. This process reduces the number of chromosomes in germ cells from diploid to haploid (half the number of chromosomes).
In humans, if the process produces sperm, it is called spermatogenesis and occurs in the testes. If the process produces ova, it is called oogenesis and occurs in the ovaries.
Spermatogenesis
Spermatogenesis is the formation of male gametes (sperm), located in the testes.
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