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
Biomes are described in terms of abiotic factors like soil type and climate, and biotic factors factors like plant and animal life.
1. Latitude and the heat transported by winds are two factors that affect global climate.
2. Other factors, among them an areas proximity to an ocean or mountain range also influence climate.
Intrusive is crystallized below the surface
<span>extrusive is when lava crystallizes on earths surface</span>
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. Karyotypes also describe the chromosomes count of an organism and the appearance of these chromosomes under the microscope. Cell which lack cell cycle control are often cancerous cells and they look different under the microscope compared to the normal cells. Cancerous cells will look different under the microscope in term of number of chromosomes, size, length, positioning and general appearance.
Virions are composed largely of nucleic acids and protein. In order to produce more virions, the host cell must synthesize more of these parts through NA replication and protein synthesis.
