Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
A quick scrape from the inside of your cheek can reveal one of biology’s most important discoveries - that all living things are made of cells. When viewed under a microscope, a thin layer of cheek cells looks like a collection of overlapping, irregularly shaped, transparent ovals. Each of these tiny structures is a cell, the smallest unit of life in your body.
Cheek cells are animal cells, meaning they lack a rigid cell wall but have a cell membrane that holds everything inside. Within each cell is a nucleus, which contains your DNA - the genetic instructions that control how your body grows and functions. The cytoplasm fills the space inside the cell, supporting tiny organelles that perform different tasks, such as producing energy or building proteins.
Scientists use cheek cell observations to teach about the structure of eukaryotic cells — cells with a nucleus and other internal structures. Comparing cheek cells to plant cells (like onion cells) reveals clear differences: plant cells have cell walls and chloroplasts, while animal cells do not.
By examining their own cells, students directly observe evidence supporting the cell theory:
All living things are made of one or more cells.
The cell is the basic unit of structure and function in living things.
All cells come from preexisting cells.
Students can compare cell structures and identify how the presence of a nucleus and cell membrane distinguishes living cells from nonliving matter.
Graph of Information - Figure 1.
Figure 2.
Which observation best supports the idea that human cheek tissue is made of cells?
Are animals made of cells?
Claim:
Evidence:
Reasoning:
Use Table 1 to compare human cheek cells (Sample A) and onion skin cells (Sample B). Describe two differences and one similarity between these cell types.
How do the observations of sand grains and filter paper (Samples C and D) help you decide whether a sample is living or nonliving?
Which statement about cell theory is most directly supported when students observe their own cheek cells under a microscope?
Explain how observing cheek cells supports the idea that cells are the basic unit of structure and function in your body.