Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
Answer:
this is because they appear dead outside and alive inside beings
aquifers yaaaaaaaay water from underground usually comes from aquifers
increase because of carbon
Answer:
Sistemas orgánicos
Explanation:
Aunque cada órgano del cuerpo realiza sus funciones específicas, los órganos también funcionan juntos por grupos, a los que se denomina sistemas orgánicos (ver Principales sistemas orgánicos). Los médicos clasifican las enfermedades y sus propias especialidades médicas de acuerdo a los diferentes sistemas orgánicos.
