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
Answer:
Genetic variability refers to a species's genetic variation as a whole. Specific changes in DNA fragments or genes are referred to as genetic variants, and each mutation of a gene is referred to as an allele.
Explanation:
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The reason why humming birds need long beaks is to be able to get the nectar from the flowers, kind of like how we need straws to drink out of to go cups. Humming birds also have very long tongues that also help this process. Since humming birds beaks help them get the food they need, it makes them more successful in their environment.
Answer:
Explanation:
Although protons resemble other positive ions such as Na+ and K+ in their movement across membranes, in some respects they are unique. Hydrogen atoms are by far the most abundant type of atom in living organisms; they are plentiful not only in all carbon-containing biological molecules, but also in the water molecules that surround them. The protons in water are highly mobile, flickering through the hydrogen-bonded network of water molecules by rapidly dissociating from one water molecule to associate with its neighbor, Protons are thought to move across a protein pump embedded in a lipid bilayer in a similar way: they transfer from one amino acid side chain to another, following a special channel through the protein.
Answer:
D. all of these
Explanation:
I just got it right in study island (:
