Topic 1.1: Introduction to Cells
Essential Idea: The evolution of multicellular organisms allowed for cell specialization and cell replacement.
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 eight functions 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 unicellular and multicellular organism.
- List characteristics of cells in a multicellular organism.
- Define and give examples of emergent properties.
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 an atypical example cell.
- Describe features of aseptate fungal hyphae that make them an atypical example cell.
- Describe features of giant algae that make them an atypical example 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 and symptoms 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.
- List the source and mechanism of obtaining stem cells.
- Outline the benefits and drawbacks in using embryonic, cord blood and adult 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.
- Given the magnification of the ocular and objective lenses, calculate the total microscope magnification.
- Measure the field of view diameter of a microscope under low power.
- Calculate the field of view diameter of a microscope under medium or high power.
- Estimate the size of a sample in the microscope field of view.
- Demonstrate how to focus the microscope on a sample.
- Demonstrate how to make a temporary “wet mount” on a microscope slide.
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 “discrepancy.”
- Explain why “trends and discrepancies” are useful in scientific study.
- List features of cells that would be considered a “trend”.
- List examples of cell types or organisms that are “discrepancies” 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
Cell Theory (unit 1)
Microscopy (unit 2)
- coming soon
Stem Cells and Differentiation (unit 5)
- Stem cells mimic human brain (2013-08-28)
- Stem cells created in living mice (2013-09-11)
- First embryonic stem cells cloned from a man's skin (2014-04-17)
- New stem cells a genetic match for adults (2014-04-18)
- Stem cells made by cloning adult humans (2014-04-28)
- 'Provocative' research turns skin cells into sperm (2014-05-01)
- Unexpected stem cell factories found inside teeth (2014-07-30)
- Preventing a cellular identity crisis (2014-07-31)
- An embryonic cell's fate sealed by speed of a signal (2014-08-05)
- Dramatic growth of grafted stem cells in rat spinal cord (2014-08-07)
- From rectal cells to neurons: Keys to understanding transdifferentiation (2014-08-14)
- Key to first cell differentiation in mammals found (2014-09-02)
- Study finds human stem cells may help to treat patients (2014-10-14)
- Reproduction, stem cell researchers set up a rescue plan for Northern White Rhino (2015-12-22)
- Researchers dig up new molecular details on 'the other type' of stem cells (2016-03-11)
- Stem-cell plan aims to bring rhino back from brink of extinction (2016-05-03)
- Breakthrough in understanding how stem cells become specialized (2016-08-04)
- The Stem-Cell Revolution Is Coming — Slowly (2017-01-16)
- Patients Lose Sight After Stem Cells Are Injected Into Their Eyes (2017-03-15)
- Lab-grown blood stem cells produced at last (2017-05-17)
- Trials of embryonic stem cells to launch in China (2017-05-31)
Cell Membrane Transport (unit 8)
- Why bacteria can’t get any bigger—or smaller (2016-04-12)