Science Exam Flashcards
(14 cards)
What are 7 characteristics of living things?
Movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition.
What are all living things made up of?
Cells.
What is a cell?
Cells are the smallest unit that can perform the functions of life.
What are some examples of cells?
Skin cells, bacterial cells, egg cells, plant cells, and nerve cells.
Explain the cell theory timeline.
Hooke 1665: Observed remains of a dead plant cell.
Leeuwenhoek 1673: First to see a living cell using a simple microscope.
Schleiden 1838: All plants are made of cells.
Schwann 1839: All animals are made of cells.
Virchow 1855: Reason that cells come from other cells.
What is the Cell Theory?
- All living things are made up of one or more cells.
- The cell is the simplest unit that can carry out all life functions.
- All cells come from pre-existing cells.
What is a prokaryotic (“before” nucleus)?
They are simple organisms as their cells do not contain a nucleus or other membrane bound organelles.
What is an example of a prokaryotic?
Bacteria.
What is a eukaryotic (“true” nucleus)?
They are complex organisms as they are cells that contain a nucleus and other organelles, each surrounded by a thin membrane.
What are examples of eukaryotic?
Plants, animals, fungi, and protists.
What are some common misconceptions?
- All animal cells are circular and all plant cells are rectangular.
2.All animals and/or plant cells are identical in terms of structure. For example, all cells contain a nucleus.
3.Cells contain only the genetic material that they use. For instance, a skin cell has DNA only for the functioning of that skin cell.
What are the truths of these misconceptions?
- Cells differ widely in terms of shape.
- Red blood cells are enucleated.
- All cells contain the DNA of the whole genome yet express only the genes that are crucial to their functioning.
What is the difference between plant and animal cells?
The difference is reflected in the structure of their cells.
