Cell Cycle and Mitosis Project

BY SIERRA AGUILAR AND SAMI WEERS

g1 phase

cell gets bigger

makes organelles

it is the first of the four stages in interphase

the cell synthesizes Mrna and proteins to get ready for mitosis

there is also a checkpoint in the g1 phase

s phase

-dna is replicated

-major checkpoint

-To produce two similar daughter cells

-synthesis

-second step in interphase

g2 phase

- the end of interphase

- directly precedes into mitosis stage

-DNA is completely replicated

-rapid cell growth

-protein synthesis during which the cell readies itself for mitosis

- its not as important or necessary but it is helpful

-has a checkpoint that proceeds to mitosis

-this checkpoint detects mutation, missing DNA, and extra DNA. it will also commit suicide called apoptosis

Prophase

-chromatin condenses into chromosomes

-centrides are synthesized

- nucleus breakdown

-first stage of mitosis

- the chromosomes become visible as paired chromatids and the nuclear envelope disappears -The first prophase of meiosis includes the reduction division

Metaphase

-chromosomes a line at the middle of the cell

-centrioles move to the opposite side of the cell

-the second stage of cell division

-between prophase and anaphase

-chromosomes become attached to the spindle fibers.

-metaphase is when the m checkpoint starts

Anaphase

-centrioles connect to the chromosomes through spindle fibers.

-cell division in which the chromosomes move away from one another to opposite poles of the spindle

-chromosomes are pulled

-the m checkpoint ends at anaphase it checks if spindle fibers do not connect to apoptosis chromosomes.

Telophase

-nuclei reform

-chromosomes unwind into chromatin

-cell membrane separates

-centrioles breaks down

-cell division starts to finish up

-the last stage of mitosis

-the cell membrane starts to close creating two separate cells

Cytokinesis

-cell membrane separates fully

- cytoplasm is separates

-two identical cells

- the end result is to daughter cells

-the end of mitosis

Down syndorme

Down syndrome also called as trisomy 21 is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. Some symptoms include physical growth delays, characteristic facial features, and mild to moderate intellectual disability. Some other symptoms include a flat facial profile, almond shaped eyes with an upward slant, unusual eyelids (known as epicanthic folds), a flat nasal bridge, a prominent tongue, small ears, single crease on the palms of the hands (known as a palmar crease), smaller limbs, smaller body frame, and a small head. Even though they may have these characteristics, babies and children with Down syndrome may still look much like other family members.

It is due because abnormal cell division results in an extra chromosome 21 in each cell. Prior to or at conception, a pair of chromosomes 21 (in either the sperm or the egg) fails to separate. As the embryo develops, the extra chromosome is replicated in every cell of the body. At present, researchers are not sure what causes the presence of an extra chromosome 21. In a person with Down syndrome, each cell makes excess amounts of chemicals regulated by the chromosome 21 genes.