By there DNA. When when x and y have sex they send there gene into the offspring
It helps the plants create oxygen for us to breathe
Interphase:
-the cell replicates its chromosomes
-each chromosome has two sister chromatids held together by a centromere
Prophase 1 chromosomes coil up and a spindle forms
-homologous chromosomes come together matched gene by gene forming a tetrad
-Crossing Over may occur when chromatids exchange genetic material
-this occurs two or three times per pair of homologous chromosomes
-Crossing Over results in new combinations of alleles on a chromosomes
Metaphase 1:
-the centromere of each chromosome becomes attached to a spindle fiber
-the spindle fibers pull the tetrads to the equator of the spindle
-homologous chromosomes are lined up side by side as tetrads
Anaphase 1:
-homologous chromosomes separate and move to opposite ends of the cell
-centromeres do not split
-this ensures that each new cell will receive only one chromosome from each homologous
pair
Telophase 1:
-the spindle breaks down and the chromosomes uncoil
-the cytoplasm divides to yield two new cells
-each cell has half the genetic information of the original cell because it has only one homologous
chromosome from each pair
Prophase II-
-a spindle forms in each of the two new cells and the fibers attach to the chromosomes
Metaphase II-
-the chromosomes are pulled to the center of the cell and line up randomly at the equator
Anaphase II-
-the centromere of each chromosome splits the sister chromatids separate and move to opposite poles
Telophase II nuclei re form the spindles break down the cytoplasm divides identical to mitosis (Meiosis II)
What Meiosis produces four haploid sex cells from one original diploid cell each haploid cell contains one chromosome from each homologous pair haploid cells will become gametes transmitting genes to offspring
I hope this helps
Animal cells migrate during morphogenesis. not plant cells
The purpose of a presumptive test is to see which substance the sample is.
