Cell Cycle

Explain the relationship between DNA, a chromosome, and chromatin.

Both chromosomes and chromatin are DNA, however they differentiate slightly. Chromatin is wound up DNA, and chromosomes are what DNA look like when a cell is getting ready to divide. Chromosomes are also symmetrical, and they have the same DNA on each side

What is the relaxed form of DNA found in the nucleus?

Chromatid

In preparation for the cell to undergo mitosis, the chromatin condenses into what type of structure?

Chromatin condenses to form chromosomes during prophase of mitosis, and during prophase I and prophase II of meiosis

Define crossing over. When does it occur?

Chromosomal crossover (or crossing over) is the exchange of genetic material between homologous chromosomes that results in recombinant chromosomes during sexual reproduction. It is one of the final phases of genetic recombination, which occurs in the pachytene stage of prophase I of meiosis during a process called synapsis.

Identify the stage of mitosis in which the cells chromosomes line up in the middle of the cell.

Chromosomes line up in the center of a cell during the metaphase portion of mitosis

Describe the difference between plant and animal cells during cytokinesis.

During plant cell cytokinesis, a cell plate is formed, beginning the division of the cell wall and cytoplasm. During animal cell cytokinesis, the cleavage furrow is formed, which is a pinching in of the cell membrane, which begins the division of the cells cytoplasm and cellular membrane.

Describe each stage during meiosis 1.

During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis. The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic recombination becomes apparent.

Describe the events that take place during telophase.

During telophase, the final stage of mitosis (or the phase in which cells split apart), cell division is finishing up. The cell membrane closes, creating two separate cells.

What activities are taking place in the cell during interphase?

G1 = gap one. The newly formed daughter cell grows by adding cytoplasm and organelles. The cell performs its normal activities, depending on what kind of cell it is. Some cells never divide, and they spend their entire lives in G1. S = synthesis. The DNA is replicated to prepare for cell division. Replication means that the DNA is copied exactly so there are two complete sets of DNA to divide up. G2 = gap two. The cell grows more to get ready to divide.

Predict what might happen if the sister chromatids did not separate during anaphase 2.

If sister chromatids were not separated during mitosis, the daughter cells would not have an exact copy of the parent cell's chromosomes.

Predict what might happen of the cell never underwent cytokinesis?

If the cell underwent mitosis without cytokinesis, the cell would have a double set of chromosomes in it because it wouldn't have split and given the copy to the new cell. Additionally, you've have a multinucleated cell.

Describe how metaphase in mitosis differs from metaphase 1 in meiosis.

In metaphase 1 of meiosis, the mitotic spindle only attaches to one pair of chromosomes from one side, so that when anaphase occurs that pair of chromosomes will end up on one side.

What stage of meiosis is depicted?

Meiosis is a two-part cell division process that produces sex cells with one half the number of chromosomes as the parent cell. There are two stages or phases of meiosis: meiosis I and meiosis II. At the end of the meiotic process, four daughter cells are produced.

Infer how meiosis increases genetic variation.

Meiosis leads to increased genetic variation by reshuffling genes and creating random genes.

Infer why mitosis does not increase genetic variation.

Meiosis leads to increased genetic variation by reshuffling genes and creating random genes. The variation produced by meiosis accounts for differences in closely related individuals, such as members of the same family, as well as genetic differences in people within larger populations

What stage of mitosis is depicted?

Mitosis is the phase of the cell cycle where chromosomes in the nucleus are evenly divided between two cells. When the cell division process is complete, two daughter cells with identical genetic material are produced. Before a dividing cell enters mitosis, it undergoes a period of growth called interphase.

How does mitosis and meiosis differ?

Mitosis occurs in somatic cells and meiosis occurs in reproductive cells.

What stages of the cell cycle are included in interphase?

Telophase

Identify the 5 stages of the cell cycle

Telophase, interphase, prophase, anaphase, metaphase

Describe what occurs during each stage of the cell cycle.

Telophase; The nuclear membrane forms and gets ready for division. Interphase; The growth and development of the cell. Prophase; The chromatids pair up; nuclear membrane dissolves & centrioles & spindle fibers go to opposite ends. Anaphase; The chromosomes separate by the spindle fibers pulling them apart. Metaphase; The paired chromatids (chromosomes) line up in the center of the cell.

List the 4 stages of mitosis in the correct sequence.

The four basic stages of mitosis are: 1 PROPHASE. 2 METAPHASE. 3 ANAPHASE. 4 TELOPHASE.

Define mitosis.

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

Compare meiosis 1 and meiosis 2.

meiosis 1 the result is 2 different cells with diploid (or duplicated haploids) chromosomes and for meiosis 2, the result is 4 different haploid cells. meiosis 1 the result is 2 different cells with diploid (or duplicated haploids) chromosomes and for meiosis 2, the result is 4 different haploid cells.

Describe the events that take place during anaphase

the alignment of chromosomes at the center of the cell and the subsequent separation of sister chromatids to opposite mitotic spindle poles.

Describe the events that take place during prophase.

the chromatin condenses to become chromosomes, which will later be separated in various ways during the final stages of mitosis and meiosis.

While looking through a microscope, you see a cleavage furrow develop. What stage is this cell in, and what type of cell is it?

the cleavage furrow is the indentation of the cell's surface that begins the progression of cleavage, by which animal and some algal cells undergo cytokinesis, the final splitting of the membrane, in the process of cell division.

What is cytokinesis?

the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.