What is a chromosome?
carry the cell's coded genetic information and proteins
specific number of proteins
chromatins condense into chromosomes
What is a chromatid?
the replicated chromosome
each cell has two of these identical "sister"
What is a centromere?
THe area where each pair of chromatids is attached
located neaer the midle of the chromatid
What is interphase?
The period of the cell cycle between cell divisions
What happens during the cell cycle?
-Prepares for divison
-divides to form two daughter cels
What are the four phases of the cell cycle?
What are the three parts interphase is divided into?
What are the four phases of mitosis?
What happens in prophase?
-Centrioles (two tiny structures located in the cytoplasm by the nuclear envelope) separate
-Centrioles in a region called the centrosome that organizes the spindle (helps separate the chromosome
-condensed chromosomes become attached to fibers in the spindle near the centromere of each chromatid
-chromosomes coil tightly and nuclear envelope breaks down
What happens in metaphase?
-only lasts a few minutes
-chromosomes line up across center of the cell
-microtubules conncect centromer of each chromosome to tow poles of the spindle
What is anaphase?
-centromers joining the sister chromatids split (sisters are then able to become individual chromosomes)
-chromosomes continue to move until they have separated intwo two groups near poles of spindle
-ends when chromosomes stop mving
What is telophase?
-final phase of mitosis
-chromosomes begin to disperse into a tange of dnese material
-nuclear envelope re-forms around each cluster of chromosomes
-spindle breaks apart
-nucleolus becomes visible in each daughter nucleus
What happens to the cells after mitosis?
-two nuclei each with a duplicate set of chromosome is formed-in cyroplasm of a singel cell
What is cytokinesis (animal cells)?
-occurs at the same time as telophase
-in animal cells:
-cell membrane is drawn inward until the cytoplasm is pinched into two equal parts (contians own nucleus and cytoplasmic organelles)
What happens in cytokinesis (plant cells)?
-cell plate forms midway between devided nuclei
-cell plate gradually develops intoa separating membrane
-cell wall then begins to appear in the cell plate