Mitosis Notes Biology

Interphase
• DNA is (# of chromosomes doubles)
• DNA appears as (chromatin) at the start, but change to at the end of this phase.

Prophase
• (cell begins to divide)
• appear and begin to move to of cell (only in animal cells)
• form between the poles (made of microtubules)
• starts to disappear

Metaphase
• attach to the spindle fibers at the of the cell.

Anaphase
• when the and begin to move to opposite ends of the cell (spindle fiber ).

Telophase
•
• Chromosomes appear as
• Spindle fibers and disappear

Cytokinesis
• Cell membrane moves inward to create - each with its own nucleus with

Control of the Cell Cycle
• Controlled by enzymes called and
1. (G1): decide whether the cell will divide
2. (G2): checks DNA replication
3. (M): triggers exit from mitosis

Cancer
• division of cells
• Cancer cells to the body’s control mechanisms.

Apoptosis
• Programmed
• Cells that are no longer
• fingers and toes
• cells
• leaves

Stem Cells
• cells that can be programmed to develop into cells
• - 100-150 stem cells
• Adult stem cells – also called stem cells

Rank the three variables in terms of how strongly they affect the "species" composition of the bacterial communities. place the variable with the weakest effect on the left and the variable with the strongest effect on the right.

The galapagos island contain 13 species of finches four of the species are seen here it is believed that all of the species had one common ancestor and overtime

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.