Lab: Mitosis and Meiosis AP BIO
24 hours
The length of the cell cycle is approximately this much for cells in actively dividing onion root tips
apical meristem
The region that contains the highest percentage of cells undergoing mitosis
What activities are going on in the cell during interphase?
Usual cell activity is going on; it's usual functions. The centrosome forms and chromosomes are not visible. DNA is duplicated in this phase.
How does plant mitosis accommodate a rigid, and flexible cell wall?
Vesciles form a line and grow against the cell walls, forming a strong wall separating the nuclei.
Is the centrosome necessary for mitosis?
Yes. The centrosomes attach to the chromosomes to pull them apart and help the cell divide, overall, but during anaphase.
Karyokinesis
division of the cell's nucleus
Cytokinesis
division of the cytoplasm -plants: new cell wall from cell plate -animals: cleavage furrow
Mitosis
typically results in new somatic (body) cells -formation of an adult organism from a fertilized egg, asexual reproduction, regeneration, and maintenance or repair of body parts
region of maturation
where root hairs develop and where cells differentiate to become xylem, phloem, and other tissues
root cap
tough covering of the root tip that protects the meristem
region of cell division
Composed of apical meristem in the center of root tip -"zone of cell division"
Explain how mitosis leads to two daughter cells, each of which is diploid and genetically identical to the original cell.
DNA and organelles duplicate, creating enough material to create two of itself, two daughter cells. The cells split into two identical cells.
Interphase
DNA replication occurs
How does mitosis differ in a plant and animal cells
Plant cells split via a cell plate, and an animal cell splits with a cleavage furrow.
region of elongation
The area in which growth occurs
anaphase
The centromere regions of each pair of chromatids separate and are moved by the spindle fibers towards opposite poles of the spindle -once two chromatids separate, each is called a chromosome -continue until the daughter chromosomes form two compact clumps
What is the role of the centrosome (The area surrounding the centrioles)?
The centrosome organizes the microtubules.
Metaphase
The chromosomes have moved to the center of the spindle -The centromere attaches to the spindle -The centromere of all the chromosomes lie on a plane called the metaphase plate
prophase
The first sign of division occurs -thickening of the chromatin threads, which continues until it has condensed into chromosomes -nuclear envelope and nucleoli are no longer visible -first sign of a spindle appears
root cap
functions in protect
root hairs
increase surface area (so more H2O can be taken in the onion root tips)
chromosome
is composed of two chromatids joined at a centromere
spindle apparatus
is made up of microtubules that pull the chromosomes toward the poles of the spindle where the two daughter nuclei will eventually form
Telophase
last stage of division -formation of a new nuclear envelope around each group of chromosomes -chromosomes gradually uncoil to form chromatin (in interphase) -nucleoli and nuclear envelope reappear
whitefish blastula
often used for the study of cell division -as soon as the egg is fertilized, it begins to divide
Epidermis
outermost layer of skin (onion root tips)
time in each phase equation
percentage of cells in stage x 1440 minutes= The number of minutes of the cell cycle stage
Meiosis
results in the formation of either gametes (in animals) or spores (in plants) -These cells have half the chromosome number of the parent cell
region of maturation
root area from which root hairs and lateral roots emerge
Meristems
special growth regions where the process of forming new cells is restricted to -in higher plants