Answer:
Crossing-over between homologous chromosomes (prophase 1), the random lining of homologous chromosomes (metaphase 1), and random fertilization are the mechanisms involved in genetic variation.
Explanation:
Crossing-over between homologous chromosomes (prophase 1), the random lining of homologous chromosomes (metaphase 1), and random fertilization are the mechanisms involved in genetic variation.
The Crossing-over events occur between two homologous chromosomes in the equatorial plane and make the daughter cells genetically different from the original one. The Chiasma is the position where two homologous chromatids interchange genetic information, giving a place for new genetic material or information to be provided to descendants. After crossing over, homologous chromosomes get separated again.
On the equatorial plane, homologous paired together, randomly aline with their kinetochores facing opposite poles. The random arrangement of tetrads is different in every cell going through the meiosis process. There is no equal alinement between two cells. When tetrads aline in the equatorial plane, there is no predetermined order for each of the homologous chromosomes of each tetrad to face one of the poles and then migrate to it while separating. Chromosomes of the homologous pair arrange to face any of the poles to migrate forward to it. Each of the chromosomes has two possibilities for orientation at the plane. When the new haploid cells are formed, the number of variations in each cell is also different and depends on the chromosomes that form that cell. The order in the equatorial plane is what introduces variation into the gametes, being almost impossible for two gametes to have the same genetic charge.
Independent assortment occurs when the alleles from two or more different genes distribute in gametes independently from each other. In other words, a gamete receives an allele from a gene that does not depend on nor influence the allele of another gene in the same gamete. This can only be applied to independent genes. An organism gets only one of the members of the chromatids pair of each parent.
Answer:
B
Explanation:
Y chromosomes are the male chromosome. A person with an XY sex chromosome pair will be male while that with an XX sex chromosome pair will be female. This is because the Y chromosome has a male-determining gene called the SRY. This gene is responsible for the development of testis.
The nervous system<span> is like a highway along which </span>your <span>brain sends and receives information about what is happening in the body and around it. This highway is made up of billions of nerve cells, or neurons (say new-rons) which join together to make </span>nerves<span>. A nerve is a fibre that sends impulses through the body.</span>
Answer:
velocidad de reacción
Explanation:
Las enzimas son proteínas que catalizan reacciones, es decir, aumentan la velocidad de reacción. Si se quiere evaluar el efecto de cambiar el pH en una reacción enzimática, se debe realizar la reacción a distintos valores de pH e ir midiendo la velocidad de reacción. Por lo tanto:
pH: variable independiente
velocidad de reacción: variable dependiente
La velocidad de reacción podría medirse a través de la cantidad de producto que se forma por unidad de tiempo, o a través de la cantidad de sustrato que se consume por tiempo.
