CELL DIVISION STUDY GUIDE!!!!!!!!!!!!!!!!!!!!!!! – Flashcards
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cell cycle
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the regular sequence of growth and division that cells undergo.
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Interphase
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the stage of the cell cycle that takes place before cell division occurs; during this stage,the cell grows, copies its DNA, and perepares to divide.
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replication
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the process by which a cell makes a copy of the DNA in its nucleus.
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Mitosis
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the stage of the cell cycle during which the cell's nucleus divides into two new nuclei and one copy of the DNA is distributed into each daughter cell.
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chromosome
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a doubled rod of condensed chromatin; contains DNA that carries genetic information.
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chromatid
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1 of the identical rods of a chromosome.
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cytokinesis
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the final stage of the cell cycle, in which the cell's cytoplasm divides, distributing the organelles into each of the 2 new cells
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how does an organism increase in size
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During Interphase the cell doubles in size and produces all structures needed to carry out it's functions. Both mitochondria and chloroplasts makes copies of themselves during the growth stage.
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What are the stages of the cell cycle in order.
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Interphase, Mitosis:Prophase, Mitosis:Metaphase, Mitosis:Anaphase, Mitosis: Telophase, Cytokinesis
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What happens in each part of the cell cycle? (1st phase)
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Interphase- the cell grows to its mature size, makes a copy of its DNA and prepares to divide into two cells.
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2nd phase in cell cycle
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Mitosis: Prophase- The chromatin in the nucleus condenses to form chromosomes. Structures called spindle fibers form a bridge between the ends of the cell. The nuclear membrane breaks down.
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3rd phase in cell cycle
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Mitosis: Metaphase- The chromosomes line up across the center of the cell. Each chromosome attaches to a spindle fiber at its centromere, which still holds the chromatids together.
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4th phase in cell cycle
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Mitosis: Anaphase- The centromeres slit. The two chromatids separate. One chromatid moves along the spindle fiber to one end of the cell. The other chromatid moves to the opposite end. The cell becomes stretched out as the opposite ends pull apart.
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5th phase in cell cycle
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The chromosomes begin to stretch out and lost their rodlike appearance. This occurs in the two at the ends of the cell. A new nuclear membrane forms around each region of chromosomes.
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6th phase in cell cycle
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Cytokinesis- The cell membrane pinches in around the middle of the cell. Eventually, the cell pinches in two. Each daughter cell ends up with the same number of identical chromosomes and about half the organelles and cytoplasm.
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What is the purpose of the spindle fibers?
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Spindle fibers form a bridge between the ends of the cell.
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What is the longest stage of the cell cycle?
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DNA Replication (10 hours)
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How are DNA molecules structured?
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DNA molecules are structured like a ladder or spiral staircase. The two sides of the DNA ladder are made up of molecules of a sugar called deoxyribose, alternating with molecules known as phosphate
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What is the DNA shape normally called?
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Double helix- a helix is a shape that twists like the threads of a screw.
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Who were the two scientists who figured out the structure of DNA?
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James Watson and Francis Crick
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What are the four nitrogen base pairs if DNA? Which base pairs with which base?
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Adenine (A), thymine (T), guanine (G), and cytosine (C). Thymine pair with Adenine (T-A), Guanine pair with cytosine, (G-C)
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Interphase sometimes is referred to as the "resting" stage of a cell cycle. Why is this reference misleading?
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The reference is misleading because the cell is actually still functioning during this phase; it is preparing for mitosis. The cell grows and works as normal, as well as replicating its DNA ready for the next stage with is mitosis.
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Explain how DNA replication occurs, and how the structure of DNA allows this kinds of replication to take place.
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During DNA replication, a DNA molecule "unzips" between its paired bases. New bases pair with the base of each strand. As a result, two identical DNA molecules form.
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Why is DNA replication so important?
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DNA holds all the information that the cell needs to carry out its functions. The replication of a cell's DNA is very important, since each daughter cell must have a complete set of DNA to survive.
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How is a cell able to produce two almost-identical daughter cells?
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At the end of DNA replication, the cell contains two identical sets of DNA. One set will be distributed to each daughter cell.
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Compare and contrast cytokinesis in animals cells and plant cells.
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During cytokinesis (animal cells) the cell membrane squeezes together around the middle of the cell. In plant cells the rigid cell wall can't squeeze together in the same way that a cell membrane can. They both have daughter cells.
