Topic 1.1:  Introduction to Cells

Essential Idea: The evolution of multicellular organisms allowed for cell specialization and cell replacement.
At SHS, Topic 1.1 is taught in the following class unit(s):

Statements and Objectives

1.1.U1  ​According to the cell theory, living organisms are composed of cells.
  • State the three parts of the cell theory.
  • Outline evidence that supports the cell theory.
  • Compare the use of the word theory in daily language and scientific language.
1.1.U2  Unicellular organisms carry out all functions of life.
  • Outline the functional characteristics of life.
1.1.U3  ​Cell Surface to volume is an important limitation to cell size.
  • ​Outline the activities occurring in the volume and at the surface of the cell.
  • Calculate the surface area, volume and SA:V ratio of a cube.
  • Explain the benefits and limitations of using cubes to model the surface area and volume of a cell.
  • Describe the relationship between cell size and the SA:V ratio of the cell.
  • Explain why cells are often limited in size by the SA:V ratio.
  • List three adaptations of cells that  maximize the SA: volume ratio.
1.1.U4  ​Multicellular organisms have properties that emerge due to the interaction of their cellular components. 
  • Define and provide an example of a multicellular organism.
  • Define and provide an example of a unicellular organism.
  • Define “emergent property.”​
  • Provide an example of emergent properties at different hierarchical levels of life.
1.1.U5  ​Specialized tissues can develop by cell differentiation in multicellular organisms.
  • Define tissue.​
  • Outline the benefits of cell specialization in a multicellular organism.
  • Define differentiation.​
1.1.U6  ​Differentiation involves the expressions of some genes and not others in a cell’s genome.
  • Describe the relationship between cell differentiation and gene expression.
1.1.U7  ​The capacity of stem cells to divide and differentiate along different pathways is necessary in embryonic development and also makes stem cells suitable for therapeutic uses.
  • Define zygote and embryo.
  • List 2 key properties of stem cells that have made them on the active areas of research in biology and medicine today.
  • Explain why stem cells are most prevalent in the early embryonic development of a multicellular organism.
  • Contrast the characteristics of embryonic, umbilical cord and adult somatic stem cells.
  • Define totipotent, multipotent and pluripotent.
​1.1.A1  ​Questioning the cell theory using atypical examples, including striated muscle, giant algae and aseptate fungal hyphae.
  • Describe features of striated muscle fibers that make them a discrepancy from a atypical cell.
  • Describe features of red blood cells that make them a discrepancy from a atypical cell.
  • Describe features of aseptate fungal hyphae that make them a discrepancy from a atypical cell.
  • Describe features of giant algae that make them a discrepancy from a atypical cell.​
​​1.1.A2  ​Investigation of functions of life in Paramecium and one named photosynthetic unicellular organism.
  • Describe characteristics of Paramecium that enable it to perform the functions of life.
  • Describe characteristics of Chlamydomonas that enable it to perform the functions of life.
1.1.A3  ​Use of stem cells to treat Stargardt’s disease and one other named condition.
  • Outline the cause and symptoms of Stargardt’s disease.
  • Explain how stem cells are used in the treatment of Stargardt’s disease.
  • Outline the cause of leukemia.
  • Explain how stem cells are used in the treatment of leukemia.​
1.1.A4  ​Ethics of the therapeutic use of stem cells from specially created embryos, from the umbilical cord blood of a new-born baby and from an adult’s own tissues.
  • Discuss the benefits and drawbacks in using adult stem cells.
  • Discuss the benefits and drawbacks in using embryonic stem cells.
  • Discuss the benefits and drawbacks in using cord blood stem cells.
1.1.S1  ​Use of a light microscope to investigate the structure of cells and tissues.  Practical 1
  • Label the names of parts of the microscope.
  • Define magnification.
  • Given the magnification of the ocular and objective lenses, calculate the total microscope magnification.
  • Define "field of view."
  • Outline how to determine the diameter of a field of view using low power magnification.
  • Calculate the field of view diameter of a microscope under medium or high power.
  • Outline how to estimate the size of a sample in the microscope field of view.
  • Demonstrate how to focus the microscope on  a sample.​
1.1.S2  ​Drawing of cell structures as seen with the light microscope.
  • Demonstrate how to draw cell structures seen with a microscope using sharp, carefully joined lines and straight edge lines for labels.​
1.1.S3  ​Calculation of the magnification of drawings and the actual size of structures and ultrastructures shown in drawings or micrographs. 
  • Define micrograph.
  • State why the magnification of a drawing or micrograph is not the same as the magnification of the microscope.
  • Use a formula to calculate the magnification of a micrograph or drawing.
  • If given the magnification of a micrograph or drawing, use a formula to calculate the actual size of a specimen.​
1.1.NOS1  ​Looking for trends and discrepancies- although most organisms conform to cell theory, there are exceptions.
  • Define "trend" and explain why trends are useful in scientific study.
  • Define "discrepancy" and explain why discrepancies are useful in scientific study.
  • List features that would be considered a “trend” related to the cell theory.​
1.1.NOS2  ​Ethical implications of research- research involving stem cells is growing in importance and raises ethical issues.
  • Explain why biological research must take ethical issues into consideration.

In the News
"When we try to pick out anything by itself, we find it hitched to everything else in the Universe." 
 John Muir,   1911