Meiosis & Cell Cycle Regulation Flashcards
How is the cell cycle regulated? Distinguish between internal and external regulation. Describe the role of Cyclins in the Cell Cycle
The cell cycle is regulated because the cycle contains regulatory proteins on the inside and outside of the cell. It also regulates when the cell should grow and divide. Internal regulation is a protein that responds inside the cell, and it helps the cell cycle to proceed when certain events occur. External regulation have proteins that direct the cells to speed up or slow down the cell cycle.
What is the purpose of apoptosis
Apoptosis is the programmed of cell death. The purpose is to shape the tissue and organs in an animals and plant cells.
How do cancer cells differ from noncancerous cells?
Cancer is the ability that a cell looses the ability to grow/i in control. Cancer cells differ from noncancerous cells because they do not responde to the signals given to them, that regulate the cell growth in most cells.
What are some of the causes of cancer? What are some of the treatments of cancer?
Many cancers are caused by the defects in a persons genes, which regulate cell growth and division. Some ways that cancer can be treated are surgically removed if it has been spotted early in the process, radiation-beams of radiation, and chemotherapy. Chemotherapy is the process which has 6 stages, and it targets rapidly dividing cells, but it also interferes with regular cell division in normal healthy cells.
What are stem cells? What are some of the possible benefits associated with stem cell research?
Stem cells are unspecialized cells that form when differentiated cells develop. Some benefits of stem cell research is using undifferentiated cells to make repairs, replace the badly damage cells, and tissues. An ethical research for stem cells, that harvesting them will lead to damage, and lead to death of the embryo
Apoptosis
process of programmed cell death
Cancer
disorder in which some of the body’s cells lose the ability to control growth
Cyclin
one of a family proteins that regulates the cell cycle in eukaryotic cells
Differentiation
process in which cells become specialized in structure and in function
Embryo
developing stage of a multicellular organism
Growth factor
one of a group of external regulatory proteins that stimulate the growth and division of cells
Metastasis
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Pluripotent
cells that are capable of developing into most, but not all, of the body’s cell types
Regulation
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Stem Cells
unspecialized cell that can give rise to one or more types of specialized cells
Totipotent
cells that are able to develop into any type of cell found in the body (including the cells that make up the extraembryonic membranes and placenta)
Tumor
mass of rapidly dividing cells that can damage surrounding tissue
What is meiosis? What is its purpose? What events occur during each phase of meiosis?
Meiosis is the process in which the number of chromosomes per cell is cut in half though the separation of the homologous chromosomes in a diploid cells. Meiosis is a reductive system. The chromosomes are copied once and then the cells are divided twice to produce 4 haploid cells. Meiosis has two process. Meiosis I and meiosis II. In meiosis I, we have four different phases: Prophase I, Metaphase I, Anaphase I, Telophase I, and Cytokinesis.
Prophase I: the replicated chromosomes get paired with its corresponding homologous chromosomes, these paris contain four chromatids which are called tetrads. As the homologous chromosomes form the tetrads, it undergoes a process called crossing-over.
Metaphase: The spindle fibers form and attach to each tetrad. The paired chromosomes line up on the metaphase plate. Spindle fibers are attached to just one side of each chromosome.
Anaphase I:The homologous pair of chromosomes separate from one another and move toward either pole.
Telophase I: The separated chromosomes cluster at either pole and begin to uncoil. The nuclear membrane reforms around each cluster of chromosomes.
Cytokinesis: The cytoplasm separates to form two cells (each haploid). The cells may enter a short interphase.
NOTICE: THE CHROMOSOMES ARE NOT REPLICATED BEFORE THE SECOND DIVISION!!!
In Meiosis II, is very similar to mitosis.
Prophase II: Centrioles migrate to either pole. Spindle fibers form and attach to both sides of each chromosome. The nuclear membrane breaks down.
Metaphase II: he chromosomes lines up in the middle of the cell
Anaphase: The centromere breaks and the sister chromatids separate to become daughter chromosomes.
Telophase II: he chromosomes reach either pole and begin to uncoil. The nuclear membrane reforms and the spindle fibers break down.
Cytokinesis: would separate the two cells into four haploid daughter cells.
Where in your body does meiosis occur? Can just any ordinary cell undergo meiosis?
Meiosis occurs in the haploid gametes (sex cells). This only occurs in the gonads (ovaries or testes). So, no, not just any cell can undergo meiosis.
How are haploid cells different than diploid cells? How does meiosis produce cell with half the number of chromosomes?
Haploid cells are different then diploid cells because the haploid cells…
How is meiosis different than mitosis? What are the different goals of the two processes?
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While mitosis divided the nucleus of one cell to produce two cells with exactly the same DNA (clones), meiosis copies the chromosomes once but divides the cell twice so that each of the four cells that are produced (gametes) will have half the number of chromosomes as the parent cell.
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In Prophase I, each chromosome pairs with its corresponding homologous chromosome to form a tetrad
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When these homologous chromosomes pair up in prophase I, they exchange portions of their chromatids in a process called “crossing over”. You should understand that crossing-over will produce new combinations of alleles in the cell
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