bio

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10.1. Main reasons why cell divides; larger Cell=demands more place for the dna. Larger cells=less moving nutrients and Waste materials across the cell membrane. information overload: cell Grows, information is used to build the molecules needed for cell growth. Dna Doesnt increase. exchanging materials:food, oxygen,water enter by The cell membrane, waste products also go out like that. division of The cell:forms 2 daughter cells, cell divison:process in Which a cell divide into 2 daughter cells. Before the division occurs, the cell Replicates the dna, each daughter cell have a copy of dna. asexual Repro. 1parent, cell divide by fision, little chances of genetic Variation, found in bacterias, 2 offsprings. sexual repro.2 Parents, cell divide by meiosis, genetic variation, found on mammals, 1 Offspring. both.forms of reproduction, involve living things, Produce offspring. 

10.2.Chromosomes:packages of dna. prokaryotic Chrom.lack of nuclei, dna is found in cytolasm.eukaryotic chrom.more Dna, multiple chrom., chromatin: complex of a chrom. And Protein. CELL CYCLE, during the cell cycle, cell grows, Preparesfor division, divides 2 daughter cells.eukaryotic cell cycle:1. G1:cell growth, 2. S: Dna replication, 3.G2: preparing For cell division, 4.M: cell division, process of mitosis.Mitosis:division Of the cell nucleus.Cytokinesis:division of the cytoplasm. cytokinesis (animals):cell membrane is drawn inward until the cytoplasm is pinched into 2 nearly equal parts.Each part contains its own nucleus.cytokinesis in plants cell Membrane is not flexible enough, cell plate forms halfway between the divided Nuclei. A cell wall then forms in between the 2 new membranes and completes the Process.  

10.3. Regulate cell: cyclin;protein That regulate, produce in all the nodividing cell, stop virus. regulatory Proteins;internal,regulates all that happen inside the cell.External:incharge Of everything that happen inside the cell,skin,hair,bones,speed up or slows Down the cell cycle,-growth factor: stimulate the growth and division of Cells. apoptosis;sucide mecansim, they are programmed to die, Breaking down, clean. CANCER:disorder in which body cells lose the Ability to control growth.cancer cells do not respond to the signals that Regulate the growth of most cells, result the cells divide uncontrollably.tumor:cancer Cells form a mass of cells.-bening tumor: does not spread.-malignant tumor: Invade and destroy surrounding healthy tissues. A cancer cell spread, absorb The nutrients needed by other cells, block nerve connections,and prevent the Organs they invade from functioning properly. Cancer is a cause of defects in The genes that regulates cell growth and division. *treatments: surgery, Radiation (chemotherapy) specialize. 

10.4.Cell Diferentation: embryo:develope stage, from which adult organisms is Gradually produced. During  the development process, an organisms cells Become more differentiated and specializated for particular functions. Differentation:process by which cells Become specialized.During the development of an organism, cells differentiate Into many types of cells.Mapping differentation process that determines a cells utimate identity, such as Whether it will spend its life as a nerve or a muscle. Differentation in mammals:cell differentation is controlled by a number Of interacting factors in the embryo, many of which are still not well Understood. Lo que se sabe es que adult cell generally do reach a point at Which their differentation is complete-when they can became other type of cell. Totipotent: cell types that can do Everything, to develop into any type of cell in the body. Blastocyst:ball of cells with a cluster of cells inside known as The inner cell mass. Pluripotent:(inner Cell) cell can develop into any of the bodys cell types, although they Generaly cannot form the tissue surrounding the embryo. Stem cells: Unspecialized cells from which differentiated cells develop. –adult stem cells: They are multipotent, brain,muscles,heart. –embryonic stem cells: they are more Versatile, capable of producig every cell type in the body. 

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