Question

imagine you could examine the objects and materials listed below with a powerful microscope that allows you to see evidence of cell structure.
put an x next to the objects or materials that are made up, or were once made up, of cells.
_ flowers _ apples
_ skin _ sand
_ proteins _ worms
_ rocks _ bacteria
_ milk _ leaf
x bone ___ seeds
_ lungs _ water ___ paramecium
_ hamburger _ molecules x blood ___ chromosomes
_ dna _ sugar _ cell membrane _ saliva
_ calcium _ chlorophyll _ mushrooms _ atoms
explain your thinking. describe the “rule” or reason you used to decide whether something is or was once made up of cells.
uncovering student ideas in science, volume 1, second edition
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Explanation:

Part 1: Marking Objects with Cells

To determine which objects are made (or were once made) of cells, we use the rule that living organisms (or parts of once - living organisms) are composed of cells.

• Flowers: They are part of plants (living organisms), so we mark with X.
• Apples: They are parts of plants (living organisms), so we mark with X.
• Skin: It is part of the human body (a living organism), so we mark with X.
• Sand: It is a non - living, inorganic material, so we do not mark.
• Proteins: They are molecules, not living organisms or parts of them, so we do not mark.
• Worms: They are living organisms, so we mark with X.
• Rocks: They are non - living, inorganic materials, so we do not mark.
• Bacteria: They are single - celled living organisms, so we mark with X.
• Milk: It is a product of living organisms (mammals) but is a mixture of substances, not made of cells in the same way as the organism itself. However, since it comes from a living organism, if we consider the source, but strictly speaking, milk is not made of cells. But if we think about the fact that the mammary glands that produce it are made of cells, there can be some confusion. But in the context of this question, it is better to not mark it as it is a fluid with nutrients, not a cellular structure. So we do not mark.
• Leaf: It is part of a plant (living organism), so we mark with X.
• Seeds: They are parts of plants (living organisms), so we mark with X.
• Lungs: They are part of the human body (living organism), so we mark with X.
• Water: It is a non - living, inorganic substance, so we do not mark.
• Paramecium: It is a single - celled living organism, so we mark with X.
• Hamburger: It is made from meat (once - living animal tissue), so we mark with X.
• Molecules: They are non - living chemical entities, so we do not mark.
• Blood: It is a tissue in the human body (living organism) made of cells (red blood cells, white blood cells, etc.), so we mark with X.
• Chromosomes: They are structures within cells, not living organisms or parts of them in the sense of being made of cells. They are components of cells, so we do not mark.
• DNA: It is a molecule within cells, not a living organism or part of one made of cells, so we do not mark.
• Sugar: It is a molecule, not a living organism or part of one, so we do not mark.
• Cell membrane: It is a structure within a cell, not a living organism or part of one made of cells, so we do not mark.
• Saliva: It is a fluid produced by living organisms (humans) but is a mixture of substances, not made of cells. So we do not mark.
• Calcium: It is an element, not a living organism or part of one, so we do not mark.
• Chlorophyll: It is a molecule in plant cells, not a living organism or part of one made of cells, so we do not mark.
• Mushrooms: They are living fungi, so we mark with X.
• Atoms: They are the basic units of matter, not living organisms or parts of them, so we do not mark.

Part 2: Explaining the Rule

The rule is based on the fact that cells are the basic unit of life. Living organisms (like plants, animals, bacteria, fungi) and parts of once - living organisms (like hamburger, bone) are composed of cells. Non - living things such as sand, rocks, water, molecules, atoms, and substances like proteins, sugar, chlorophyll, DNA, chromosomes, cell membrane (which is a cell component), milk, saliva, and calcium are not made of cells because they do not have the properties of living organisms or are not parts of once - living organisms in a cellular - composed way.

of the Rule:
Objects that are living organisms (or parts of once - living organisms) are made (or were once made) of cells. Non - living things (e.g., sand, rocks, water, molecules, atoms) and non - cellular substances (e.g., proteins, sugar, chlorophyll, DNA, chromosomes, cell membrane, milk, saliva, calcium) are not made of cells.

Answer:

Marked Objects (with X):

• flowers
• apples
• skin
• worms
• bacteria
• leaf
• seeds
• lungs
• paramecium
• hamburger
• blood
• mushrooms
• bone (already marked)