. La cría de animales de granja. El ganado. Los órganos reproductivos Y LAS CÉLULAS GERMINALES 19 evitar una duplicación en el nuevo individuo. Este cromosoma reducción tiene lugar durante la división celular, y se denomina maduración (Fig. 7). En el óvulo, el proceso es conocido como oogenesis y en el espermatozoide como espermatogénesis. La madura Qgg o células de esperma, con la mitad de su número normal de cromosomas se denomina gameto, mientras que el óvulo fertilizado que está formado por la unión de dos gametos masculinos y femeninos, se denomina cygote encadenado, o célula. En el macho esta reducción proceso es continuo, y maduran las células de esperma son st

• Colaborador/a: Library Book Collection / Alamy Foto de stock
• ID de la imagen: RH6R0Y
• Tamaño: 7,2 MB (193,3 KB Descarga comprimida)
• Autorizaciones: Modelo - no | Propiedad - no
• Dimensiones: 1690 x 1479 px | 28,6 x 25 cm | 11,3 x 9,9 inches | 150dpi

Más información

Esta imagen es de dominio público, lo cual quiere decir que los derechos de autor han expirado en relación con la imagen o bien el titular ha renunciado a sus derechos de autor. Alamy le cobrará un precio por acceder a una copia de alta resolución de la imagen.

Esta imagen podría tener desperfectos porque se trata de una imagen histórica o de reportaje.

. Breeding of farm animals. Livestock. REPRODUCTIVE ORGANS AND GERM CELLS 19 prevent a doubling up in the new individual. This chromosome reduction takes place during cell division, and is termed maturation (Fig 7). In the egg cell the process is known as oogenesis and in the sperm cell as spermatogenesis. The mature Qgg—or sperm—cell, with half its normal number of chromosomes is termed a gamete, while the fertilized egg which is formed by the union of two gametes—male and female—is called a cygote, or yoked cell. In the male this reduction process is continuous, and mature sperm cells are stored in considerable numbers. In the female, however, the reduction takes place very rapidly and just prior to uniting with a mature sperm cell. In fact, in some instances, it is known to have occurred after the sperm cell has passed through the wall of the ovum. A diagrammatic representation of the process of maturation is shown in Fig. 8. The number of chro- mosomes (not shown in diagram) undergoes division, and thus re- mains constant in num- ber in each germ cell until the maturation division, or immedi- ately before the forma- tion of the mature sperm and egg cell, when they separate into two groups with- out splitting, each group going into a different cell. In this way the chromosomes are reduced to one-half the normal number. It is noteworthy in the case of the female that the mass of food is retained in the mature egg cell and. Fig. 8—Diagram Showing the Essential Facts IN THE Maturation of the Germ Cells 1. Sperm cell. 2. Egg cell. 3. Fertilized egg. A. Primordial division period. B. Growth period. C. Maturation period.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Harper, Merritt Wesley, 1877-. New York, Orange Judd

Buscar fotografías de banco de fotografías por etiquetas

• bookcentury1900
• bookdecade1910
• bookyear1914
• librosubjetivo