Unit 5
Chapter Overview
Students learn the structure of DNA, how it replicates, and the importance of this replication as it relates to the cell cycle. Students recognize that the components that make up the genetic code are universal to all living things. Students describe the stages of the cell cycle as well as the importance of the cell cycle in growth and development of organisms. They learn that disruptions in the cycle can lead to cancer or other diseases. Students recognize that cell differentiation occurs when cells do not use the same sections of DNA (genes), or they use the same sections of DNA (genes) in different proportions or at different times in development. They examine how cell differentiation leads to specialized cells in complex eukaryotic organisms. Students describe the role of DNA and environmental factors in cell differentiation.
Main Ideas
The basis of growth and development of all biological systems is cellular growth, cell division, and cell differentiation.
What is the importance of DNA replication to the growth of an organism?
What common structures, processes and heredity do all living things share? Explain.
What is the importance of DNA replication to the growth of an organism?
What is the importance of each of the stages of the cell cycle to the growth of an organism?
In what ways do specialized cells relate to cell division and cell differentiation?
How can the same DNA in every cell in an organism generate different structures and functions?
What role do DNA and environmental factors play in cell differentiation?
What are the possible effects of disruptions in the cell cycle?
Misconceptions
Students may think each cell type within an organism has its own genetic code, rather than understanding that all cells that make up an organism have the same set of genetic material.
Students may think DNA replication is part of mitosis, rather than realizing that DNA replicates during a separate phase of the cell cycle.
Students may think that cells are constantly moving through the cell cycle and dividing to make more cells, rather than understanding there is a resting phase (G o) in which cells exist in a quiescent state and are neither dividing or preparing to divide.
Students may think that each phase of the cell cycle is equal in duration, rather than understanding that interphase is much longer than mitosis, and the phases of mitosis vary in duration.
Vocabulary
Cell cycle – sequence of events that result in cell growth and division into two daughter cells
DNA – nucleic acid which has the code to make all proteins needed by an organism
DNA Replication – process by which DNA makes a copy of itself
Mitosis – the process of nuclear division
Cytokinesis – cytoplasm divides and the one cell pinches into two cells
Cancer – uncontrolled cell growth, caused by disruptions in the cell cycle
Notes
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