Living vs Nonliving Cells - Middle School Life Science

Identify the correct conclusion if you see chloroplasts in cells from a sample.

The sample is from a plant or algae (once-living or living). Chloroplasts are unique to photosynthetic organisms like plants.
Identify the correct conclusion: a microscope view shows cells in a sample. Is it living or nonliving?

Living. Presence of cells is definitive evidence of life.
Which observation best supports that something is living: cells present or only movement observed?

Cells present. Movement can be nonliving (wind, water); cells prove life.
What is a cell in life science?

The smallest unit of structure and function in organisms. Cells are the basic building blocks that perform all life functions.
What is the definition of unicellular based on cellular evidence?

Made of exactly one cell. Single-celled organisms like bacteria and amoebas fit this description.
What is the nucleus (in cells that have one)?

Organelle that contains DNA and controls cell activities. The control center found in eukaryotic cells.
What is the correct conclusion if a sample has no cells and is not from an organism?

It is nonliving. Without cells, the material cannot be from a living organism.
What is the cellular evidence that a sample contains living tissue rather than a nonliving material?

Organized cells with membranes and cytoplasm are observed. These cellular features confirm the presence of living material.
What does unicellular mean?

Made of one cell. Single-celled organisms like bacteria and amoebas.
What cell structure is the rigid outer layer found in plant cells but not in animal cells?

Cell wall. This structure provides support and protection beyond the cell membrane.
What is the key difference between unicellular and multicellular organisms?

Unicellular: 1 cell; multicellular: many cells. The number of cells determines organism complexity.
Identify the cell type that has a nucleus and membrane-bound organelles.

Eukaryotic cell. Found in plants, animals, fungi, and protists.
What is the cellular definition of a living thing used in life science?

A living thing is made of one or more cells. This is the fundamental criterion that separates living from nonliving matter.
What cellular feature do plants have that animal cells do not have?

A cell wall (and usually chloroplasts). Plant cells have rigid walls for support and chloroplasts for photosynthesis.
Which option is living based on cellular evidence: table salt crystals or algae?

Algae. Algae are photosynthetic organisms with cells; salt is a mineral crystal.
What is a eukaryotic cell?

A cell with a nucleus. Plants, animals, fungi, and protists have nuclei.
What is the main cellular feature that distinguishes most plant cells from animal cells?

A cell wall. Rigid outer layer providing structure and protection in plant cells.
What does unicellular mean?

Made of one cell. Single-celled organisms like bacteria and amoebas.
What is the function of mitochondria in many eukaryotic cells?

They release energy from food (cellular respiration). These organelles are the cell's powerhouses, converting nutrients to ATP.
Which option is cellular evidence of life: cytoplasm, a shadow, or a reflection?

Cytoplasm. Only cells contain cytoplasm; shadows and reflections are light effects.
Which option is eukaryotic: A) bacterium B) archaea C) amoeba D) cyanobacterium?

C) amoeba. Amoebas are protists with true nuclei.
Identify the correct classification: a rock thin section shows interlocking crystals with no membranes.

Nonliving. Crystals form from minerals, not biological processes.
What does multicellular mean?

Made of many cells. Organisms like plants and animals with specialized cells.
Identify the correct conclusion: An object has no cells under a microscope. Is it living or nonliving?

Nonliving. Without cells, an object cannot be alive.
Which observation best supports that a specimen is cellular: repeating box-like units or smooth uniform texture?

Repeating box-like units. Cell walls create visible boundaries between adjacent cells.
What is the correct classification if a microscope shows many membrane-bound cells in a sample?

Living (cells are present). Membrane-bound cells prove the sample contains living material.
What is the defining cellular criterion used to classify something as living?

It is made of one or more cells. All living things are composed of cells, the basic units of life.
What is the most direct cellular evidence that something is living?

It is made of one or more cells. All living organisms are composed of cells, the basic units of life.
What is a cell in life science?

The smallest unit of structure and function in living things. Cells carry out all life processes and make up all organisms.
Which option is the most reliable cellular evidence that something is living?

Observation of one or more cells. Direct visual confirmation provides definitive proof of cellular structure.
What does multicellular mean?

Made of many cells. Complex organisms like plants and animals have multiple cells.
What organelle contains DNA and is commonly visible in stained eukaryotic cells?

The nucleus. This control center directs cell activities and stores genetic material.
Which option is cellular evidence of a plant: chloroplasts, metal flakes, or salt crystals?

Chloroplasts. Green organelles for photosynthesis found only in plant cells.
Identify the correct conclusion: microscope shows no cells, only mineral grains. Living or nonliving?

Nonliving. Absence of cells confirms the material is not alive.
Which term describes an organism made of exactly one cell?

Unicellular. Single-celled organisms like bacteria and amoebas are unicellular.
Which option is living based on cellular evidence: a snowflake or an amoeba?

An amoeba. Amoebas are single-celled protists; snowflakes are ice crystals.
Identify the correct conclusion: a sample has ribosomes but no nucleus; living or nonliving?

Living (it is a prokaryotic cell). Bacteria have ribosomes for protein synthesis but lack a true nucleus.
What is the function of a nucleus in a eukaryotic cell?

It contains the cell's DNA and controls cell activities. The nucleus acts as the cell's command center for growth and reproduction.
Which option indicates living plant cells: chloroplasts visible or mineral grains visible?

Chloroplasts visible. Chloroplasts are organelles found only in living plant cells.
What structure must be present for something to be classified as cellular life?

A cell membrane enclosing cytoplasm. These structures define the boundary and contents of all cells.
What is the best cellular reason viruses are not classified as living organisms?

They are not made of cells. Viruses require host cells to reproduce and lack cellular structure.
Identify the correct conclusion: a moving object is observed, but no cells are found in it.

It is nonliving based on cellular evidence. Movement alone doesn't indicate life; cells are required.
What is the definition of a cell in life science?

The basic unit of structure and function in living things. Cells perform all life functions and build all living organisms.
Which option is cellular evidence of life: nucleus, magnetism, or melting point?

Nucleus. The nucleus controls cell activities; physical properties aren't cellular.
Which option is nonliving based on cellular evidence: a flame or a mushroom?

A flame. Fire is a chemical reaction without cells; mushrooms are cellular fungi.
What is the cellular definition of a living thing used in life science?

A living thing is made of one or more cells. This is the fundamental criterion that separates living from nonliving matter.
Which option is cellular evidence for life: cells present or only crystals present?

Cells present. Only living things have cells; crystals are nonliving mineral structures.
What is the correct conclusion if a sample contains cells with nuclei?

It is living and eukaryotic. Nuclei are found in eukaryotic cells of plants, animals, and fungi.
Identify the correct conclusion: a sample shows no cells under the microscope; is it living or nonliving by cellular evidence?

Nonliving. Without cells, the sample cannot be classified as living matter.
What is the correct classification if an object shows growth but has no cells (example: a crystal)?

Nonliving. Growth alone doesn't indicate life; cells are required.
What is the correct conclusion if a microscope shows cells in a sample?

The sample is (or was) from a living thing. Only living things (or their remains) contain cells.
What is the term for the jellylike substance inside a cell where organelles are found?

Cytoplasm. Gel-like material filling cells and suspending organelles.
What is the term for a structure inside a cell that performs a specific job?

Organelle. Examples include mitochondria, ribosomes, and chloroplasts.
Which option best distinguishes a cell from a nonliving particle under a microscope?

A bounded membrane enclosing cytoplasm. Membranes define cells; particles lack this boundary.
What is a cell in life science?

The basic unit of structure and function in living things. Cells are the smallest units that can perform all life processes.
Identify the correct conclusion: If a sample has cells, is it living or nonliving?

Living (or once living). Cells are the defining characteristic of all living organisms.
Which cell structure contains genetic material and helps control cell activities?

Nucleus. This organelle directs cell growth, reproduction, and metabolism.
What is the correct conclusion: If a sample has no cells, is it living or nonliving?

Nonliving. Without cells, something cannot be alive by definition.
Which option is cellular evidence that a sample is plant-based rather than animal-based?

Cells with a cell wall. Plant cells have rigid walls; animal cells have only membranes.
Which option is cellular evidence of an animal cell: cell wall or no cell wall?

No cell wall. Animal cells have only cell membranes, not rigid cell walls.
Identify the correct conclusion if you observe many cells in a tissue sample under a microscope.

The sample is from a living or once-living organism. Cells are only found in organisms that are or were alive.
Which option is living based on cellular evidence: a rock or a bacterium?

A bacterium. Bacteria are single-celled organisms; rocks have no cells.
What is the key difference between living and nonliving things using cell evidence?

Living things are made of cells; nonliving things are not. This cellular distinction is the fundamental criterion for life.
What is a prokaryotic cell?

A cell without a nucleus. Bacteria and archaea lack membrane-bound nuclei.
What is the function of chloroplasts in plant cells?

They perform photosynthesis to make sugars. These green organelles capture light energy to produce food for the plant.
What is the term for organisms made of many cells?

Multicellular. Organisms with many cells working together, like plants and animals.
Identify the correct term for organisms made of exactly one cell.

Unicellular. Single-celled organisms like bacteria and amoebas are unicellular.
Identify the correct conclusion: you observe cells with membranes but no nucleus. What kind of cells are these?

Prokaryotic cells. Bacteria and archaea lack membrane-bound organelles.
What is the key cellular evidence used to classify something as living?

The presence of one or more cells. All living things are made of cells; nonliving things lack cells.
Which option best indicates a living thing under a microscope: cells, bubbles, or sand grains?

Cells. Only living things have cells; bubbles and sand are nonliving.
What is the definition of a prokaryotic cell based on cellular structures?

A cell without a nucleus. DNA floats freely in the cytoplasm instead of being enclosed.
What is the name of the basic unit of structure and function in living things?

The cell. All living organisms are composed of these fundamental units.
Which option is nonliving based on cellular evidence: glass or bone?

Glass. Glass is manufactured from minerals and never contained cells.
Which option is living based on cellular evidence: a virus or a yeast cell?

A yeast cell. Yeast are single-celled fungi; viruses lack cellular structure.
What is the correct conclusion if a sample contains cells but no nuclei are visible?

It is living and likely prokaryotic. Bacteria lack nuclei but are still living single-celled organisms.
What is the term for a structure inside a cell that performs a specific job?

Organelle. Examples include mitochondria, chloroplasts, and the nucleus.
What is the correct classification if a sample shows only mineral crystals and no cells?

Nonliving (no cells are present). Minerals form crystals but never contain cellular structures.
Which structure is present in plant cells but not in animal cells: A) chloroplast B) nucleus C) membrane D) cytoplasm?

A) Chloroplast. Chloroplasts enable photosynthesis in plant cells only.
What is the correct conclusion if a sample has cell walls but no nucleus is visible?

It could be a prokaryote (living). Bacteria and archaea are prokaryotes that lack visible nuclei.
Which option shows a cell wall as cellular evidence: animal cell, plant cell, red blood cell, or neuron?

Plant cell. Rigid cell walls provide structure and protection in plant cells.
What is a cell in life science?

The basic unit of structure and function in living things. Cells carry out all life processes and make up organisms.
Which statement best distinguishes viruses from living organisms using cellular evidence?

Viruses are not made of cells. This acellular nature places viruses outside the definition of life.
Which option is nonliving based on cellular evidence: a crystal, a bacterium, or an amoeba?

A crystal. Crystals lack cells; bacteria and amoebas are single-celled organisms.
Which structure is present in plant cells but not in animal cells?

Cell wall. Provides structural support and protection in plants, fungi, and bacteria.
What is the definition of multicellular based on cellular evidence?

Made of many cells. Complex organisms like plants and animals have specialized cell types.
What is the key cellular difference between a living organism and a virus?

Viruses are not made of cells. Viruses lack cellular structure, unlike all true living things.
What observation is enough to classify an unknown sample as living based on cells?

Microscopic evidence of cells in the sample. Presence of cells is the key criterion for classifying something as living.
Which option is the strongest cellular evidence that an object is living: cells, crystals, or layers?

Cells. Only living things have cells; crystals and layers are nonliving structures.
What is the function-based identification for chloroplasts in a cell?

Organelles where photosynthesis occurs. These green structures capture light energy to make food.
Which structure is found in all cells and is strong evidence of life?

Cell membrane. Every living cell must have a membrane to control what enters and exits.
Which statement correctly describes viruses using cellular evidence?

Viruses are not made of cells. They require host cells to reproduce and lack cellular organization.
Identify the correct conclusion: you observe cell walls and chloroplasts. What type of organism is it?

Plant (or algae) cells. These structures are characteristic of photosynthetic organisms.
What is the best cellular evidence that something is nonliving?

It has no cells and no cellular structures. Absence of cells is the definitive proof of nonliving matter.
Which organelle carries out photosynthesis in a living cell?

Chloroplast. Contains chlorophyll to capture light energy and make glucose.
Which term describes an organism made of many cells working together?

Multicellular. Complex organisms like plants and animals have specialized cells.
Which option is cellular evidence of life: A) cells present B) shiny surface C) moves D) makes noise?

A) Cells present. Only living things have cells; the other options aren't cellular features.
Which option best supports nonliving: organized cells seen under a microscope or no cells observed?

No cells observed. Absence of cells is definitive evidence something is not alive.
Identify the cell type that lacks a nucleus but still has DNA.

Prokaryotic cell. Bacteria and archaea are prokaryotes with simpler organization.
Which option is a prokaryotic cell: a bacterium or a mushroom cell?

A bacterium. Bacteria are prokaryotes; mushrooms are eukaryotic fungi with nuclei.
Identify the correct classification: a virus has genetic material but no cells.

Nonliving based on cellular evidence. Without cellular structure, viruses don't meet the criteria for life.
What cellular feature distinguishes prokaryotic cells from eukaryotic cells most directly?

Prokaryotes lack a nucleus; eukaryotes have a nucleus. This nuclear difference is the defining characteristic between cell types.
Which option best describes a virus: A) unicellular B) multicellular C) acellular D) prokaryotic?

C) Acellular. Acellular means lacking cells, describing viruses perfectly.
What cellular feature is the strongest evidence that something is living?

Presence of one or more cells. All living organisms contain at least one cell as their basic unit.
Which option best indicates many cells are present: repeating compartments or a single solid mass?

Repeating compartments. Multiple cells create visible compartments; masses lack this structure.
What is the difference between a prokaryotic cell and a eukaryotic cell?

Prokaryotic lack a nucleus; eukaryotic have a nucleus. The presence or absence of a nucleus defines these cell types.
Which option is nonliving based on cellular evidence: a crystal or yeast?

A crystal. Crystals lack cells; yeast is a single-celled fungus.
Which cell structure is a boundary found in all cells?

Cell membrane. It controls what enters and exits every living cell.
What structure is present in all cells and separates the cell from its environment?

Cell membrane. This boundary controls what enters and exits every living cell.
What is the most reliable cellular criterion for deciding whether something is living?

Presence of one or more cells. Living things must have cells; no cells means nonliving.
What is the cellular criterion that most directly shows something is living?

Presence of one or more cells. All living things must have cells; it's the fundamental requirement.
Which option is cellular evidence of plant origin: cell wall present or no cell wall present?

Cell wall present. Plant cells have rigid walls for structure and support.
Identify the correct conclusion if a sample shows no cells and no cell structures under a microscope.

It is nonliving (not made of cells). Absence of cells indicates the material was never alive.
Which organelle is strong evidence of photosynthetic living cells in a sample?

Chloroplasts. These green organelles capture light energy for photosynthesis.
Identify the correct classification: a wood sample shows tube-like cells and thick cell walls.

Living or once living. Wood retains its cellular structure even after the tree dies.
Which option is the best cellular evidence that a sample is living: cells present or motion present?

Cells present. Motion can occur in nonliving things, but only living things have cells.
What is the smallest unit of life that can carry out life processes?

A cell. Cells are the basic functional units that perform all life activities.
What is the correct conclusion if a microscope shows no cells in a dry mineral sample?

It is nonliving based on cellular evidence. Absence of cells confirms the sample is not a living organism.
Choose the correct conclusion: an object moves but has no cells under a microscope. Living or nonliving by cellular evidence?

Nonliving. Movement alone doesn't indicate life; cells are required.
What is the key cellular feature that distinguishes plant cells from animal cells?

A rigid cell wall. Plant cells need extra support that animal cells don't require.
Which option is living based on cellular evidence: virus, crystal, bacterium, or fire?

Bacterium. Bacteria are single-celled living organisms; viruses lack cells.
Which organelle releases energy from food in most eukaryotic cells?

Mitochondrion. The powerhouse of the cell produces ATP through cellular respiration.
What structure provides strong cellular evidence that a cell is from a plant or fungus?

Cell wall. Cell walls provide rigid support in plants and fungi but not animals.
Which option is cellular evidence of a prokaryote: DNA in a nucleus or DNA in cytoplasm?

DNA in cytoplasm. Prokaryotes store their DNA freely in the cytoplasm without a nucleus.
What is the term for a cell type that lacks a nucleus?

Prokaryotic cell. Bacteria are the most common examples of this cell type.
What is the key cellular feature that indicates a cell is eukaryotic rather than prokaryotic?

A nucleus. Prokaryotes lack this membrane-bound control center.
What is the difference between living and once-living based on cellular evidence?

Living has functioning cells; once-living has cell remains or products. Living cells actively function; dead cells leave structural remains.
Which option is living based on cellular evidence: yeast, water, glass, or a metal coin?

Yeast. Yeast are single-celled fungi; the others lack cellular structure.
What is a unicellular organism?

An organism made of exactly one cell. Single-celled organisms perform all life functions in one cell.
What is the function of the cell membrane that all cells have?

Controls what enters and leaves the cell. This selective barrier regulates material exchange.
Which option is the best cellular reason viruses are usually not classified as living?

Viruses are not made of cells. They require host cells to reproduce and lack cellular structure.
Identify the correct term for organisms made of many cells working together.

Multicellular. Complex organisms like plants and animals have multiple cells.
What is cytoplasm in terms of identifying cells under a microscope?

Jelly-like interior fluid inside the cell membrane. This gel contains the cell's working components and chemicals.
Which conclusion is correct: A virus particle is observed, but no cells are present in the sample.

Cellular evidence does not support the sample being living. Without cells, viruses don't meet the criteria for life.
Which cell feature is present in plant cells but not in animal cells?

Cell wall. This rigid outer layer provides extra support beyond the cell membrane.
What cell structure forms a boundary around all cells and helps identify them as cells?

Cell membrane. This outer boundary controls what enters and exits cells.
What is the defining cellular evidence that something is living?

It is made of one or more cells. All living things are cellular; nonliving things lack cells.
Identify the correct label: A microscopic image shows roundish units with thin flexible boundaries.

Animal cells (cell membranes visible). Flexible boundaries without walls indicate animal cells.
Which observation is strongest cellular evidence that a sample is living: cell division, erosion, or melting?

Cell division. Only living cells reproduce; erosion and melting are physical changes.
Which statement best distinguishes living things from nonliving things using cells?

Living things are made of cells; nonliving things are not. This is the fundamental distinction based on cell theory.
What is the key cellular difference between prokaryotic and eukaryotic cells?

Eukaryotes have a nucleus; prokaryotes do not. This membrane-bound organelle distinguishes these cell types.
What is the function of a cell wall that can help you recognize plant cells?

Provides rigid support and protection. This distinguishes plant cells from flexible animal cells.
What is the main cellular difference between a virus and a living cell?

Viruses are not made of cells. They're protein shells with genetic material, not true cells.
What is the correct conclusion: Wood shows plant cell walls and growth rings; living or nonliving now?

Nonliving now (but once living). Dead wood retains cellular structure from when it was alive.
Which option is living based on cellular evidence: a seed or a pebble?

A seed. Seeds contain plant embryos with cells; pebbles are nonliving minerals.
Identify the correct conclusion: A sample contains cells that divide. Is it living or nonliving?

Living. Cell division is a key characteristic of living cells.
Which option is the best cellular conclusion about a plastic bead seen under a microscope?

Nonliving because it has no cells. Synthetic materials lack the cellular organization of life.
Identify the correct classification: a leaf cross-section shows many walled cells in a grid.

Living or once living. Plant cells form organized grids due to their rigid walls.
Which option is cellular evidence of life: nucleus, sand grain, or glass shard?

Nucleus. The nucleus is an organelle found only in living eukaryotic cells.
What term describes an organism made of many cells?

Multicellular. Organisms with more than one cell, like plants and animals.
Identify the correct classification by cells: a bacterium with one cell is what type of organism?

Unicellular organism. Single-celled organisms are classified as unicellular.
Which option is nonliving based on cellular evidence: bacteria on a slide or a mineral crystal?

A mineral crystal. Crystals form from minerals, not from cellular processes.
What is the correct conclusion if a sample shows dividing cells under a microscope?

It is living because cells are present and reproducing. Cell division shows active life processes occurring.
Identify the correct classification: a plastic fragment shows no compartments, only smooth uniform material.

Nonliving. Synthetic materials lack the cellular organization of life.
What cellular material carries genetic instructions in cells?

DNA. Deoxyribonucleic acid stores hereditary information in all cells.
Identify the correct label: A microscopic image shows box-shaped units with thick outer borders.

Plant cells (cell walls visible). Box shapes with thick borders indicate rigid cell walls.
What is the definition of a eukaryotic cell based on cellular structures?

A cell with a nucleus. Plants, animals, fungi, and protists have this cell type.
What is a unicellular organism?

An organism made of one cell. Examples include bacteria and many protists.
Which option is cellular evidence that an object is nonliving: cells present or no cells present?

No cells present. Nonliving things lack cellular organization entirely.
What is the correct conclusion if a sample shows no cells, only uniform mineral grains?

It is nonliving. Mineral grains indicate geological, not biological, origin.
What is the correct conclusion: A microscope view shows crystals with no membranes or organelles; living or nonliving?

Nonliving (no cells present). Crystals lack cellular structures like membranes and organelles.
What is the correct statement of cell theory used to classify living things?

All living things are made of one or more cells. This fundamental principle defines what qualifies as living.
Which option is living based on cellular evidence: A) rock B) bacterium C) water D) glass?

B) bacterium. Bacteria are single-celled living organisms.
What is a cell membrane in terms of identifying cells?

A thin boundary that encloses the cell. This protective barrier is essential for all living cells.
Which option is cellular evidence of a plant cell: chloroplasts, mitochondria only, no nucleus, or none?

Chloroplasts. These organelles perform photosynthesis, unique to plant cells.
Identify the cellular structure that encloses the cell and controls what enters and leaves.

Cell membrane. Acts as a selective barrier protecting the cell's contents.
What cell structure contains genetic material and controls many cell activities in eukaryotes?

Nucleus. This organelle houses DNA and regulates cell functions.
What is a cell?

The basic unit of structure and function in living things. Cells carry out all life processes and make up organisms.
What is the correct classification for a virus using cellular evidence (cells present or absent)?

Nonliving by cellular evidence (it is not made of cells). Viruses lack cellular structure, requiring host cells to reproduce.
Which option is cellular evidence for a plant cell: A) chloroplasts B) mitochondria only C) no membrane?

A) chloroplasts. Chloroplasts for photosynthesis are unique to plant cells.
Which option contains cells: a bacterium or a crystal?

A bacterium. Bacteria are single-celled organisms; crystals are nonliving minerals.
Which option is living based on cellular evidence: a seed, a flame, a cloud, or a plastic bead?

A seed. Seeds contain plant cells with potential to grow into new plants.
What is a multicellular organism?

An organism made of many cells. Multiple cells work together in these complex organisms.
What is the cellular evidence rule used to classify something as living?

Living things are made of one or more cells. This is the fundamental rule that defines life at the cellular level.
Which option is living based on cellular evidence: a bacterium or a flame?

A bacterium. Bacteria are single-celled organisms; flames are chemical reactions.
What is the correct conclusion if a sample shows no cells at any magnification?

It is nonliving based on cellular evidence. Without cells, the sample cannot be a living organism.
What is a tissue in multicellular organisms?

A group of similar cells working together. Cells organize into tissues for specialized functions.
What is the correct conclusion if a sample has a nucleus and membrane-bound organelles?

It is eukaryotic (living). These complex cells have compartmentalized organelles.
Identify the correct classification by cells: a dead leaf is living or nonliving now?

Nonliving now (it was living). Dead organisms no longer perform life functions despite having cells.
What is the correct term for a group of similar cells working together?

Tissue. Cells organize into tissues for specialized functions.
Which option is cellular evidence of life: nucleus, flame, or moving water?

Nucleus. Only cells contain nuclei; flames and water are nonliving phenomena.
Identify the correct conclusion: Under a microscope you see many cells in a sample.

The sample is from a living thing or was once living. Cells are definitive proof of biological origin.
What is the term for a living thing that consists of cells and can carry out life processes?

Organism. Any individual living thing capable of independent life functions.
What is the function of the cell membrane that supports identifying a cell as living?

Controls what enters and leaves the cell. The membrane maintains cell integrity and regulates transport.
What is the term for a cell type that contains a nucleus?

Eukaryotic cell. Found in plants, animals, fungi, and protists.
What cell structure forms a boundary around all cells and helps identify them?

Cell membrane. This flexible barrier controls what enters and exits every cell.
What is the correct classification using cellular evidence: a wooden table made from tree tissue?

Nonliving now, but made of once-living cells. Dead wood retains cellular structure from when the tree was alive.
What term describes an organism made of exactly one cell?

Unicellular. Single-celled organisms like bacteria are unicellular.
Which option is always made of cells: A) rock B) bacterium C) water droplet?

B) bacterium. Bacteria are single-celled living organisms; rocks and water lack cells.
Identify the best cellular conclusion: a microscope view shows no cells, only crystals. Living or nonliving?

Nonliving. Crystals lack cellular structure, confirming nonliving status.
Which option is living based on cellular evidence: a plastic bag or a plant leaf?

A plant leaf. Leaves contain plant cells; plastic is synthetic without cells.
Which option is cellular evidence that a microbe is living: it has cells or it is magnetic?

It has cells. Only living things have cells; magnetism is a physical property.
Identify the correct conclusion: a microscope view shows many cells with membranes; is it living or nonliving?

Living. The presence of cells with membranes confirms the sample contains life.
Which option is nonliving based on cellular evidence: bacterium, mushroom, rock, or amoeba?

Rock. Rocks are minerals without cellular structure, unlike living organisms.
Which option is the best cellular evidence that a sample is from an animal: chloroplasts, nucleus, cell wall, or none?

Nucleus. Animal cells have nuclei but lack chloroplasts and cell walls.
Which cell structure is the genetic material found in all living cells?

DNA. Contains instructions for all cellular activities and reproduction.
Which cell structure surrounds the cell and controls what enters and leaves?

Cell membrane. This flexible barrier regulates passage of materials.
Which option is cellular evidence of life: A) cells present B) shiny surface C) heavy mass?

A) cells present. Only cells indicate life; surface and mass are physical properties.
Which option is nonliving based on cellular evidence: A) mushroom B) amoeba C) fire D) algae?

C) fire. Fire lacks cells despite showing some life-like properties.
What is the term for organisms made of a single cell?

Unicellular. Single-celled organisms like bacteria and amoebas.
What is the correct term for organisms whose cells contain a nucleus?

Eukaryotes. Their cells contain a membrane-bound nucleus with DNA.
Identify the correct conclusion: A specimen has a cell membrane and cytoplasm. Is it living or nonliving?

Living. These are key components found in all living cells.
Which option is a universal feature of cells: DNA or glass fibers?

DNA. All cells contain genetic material; glass fibers are nonliving.
Which option is cellular evidence of life: cell membrane, rust, or crystal growth?

Cell membrane. Only cells have membranes; rust and crystals are nonliving materials.
Which statement best distinguishes living from nonliving using cells?

Living things are made of cells; nonliving things are not. This fundamental difference defines life at the cellular level.
Which option is nonliving based on cellular evidence: a virus or a yeast cell?

A virus. Viruses lack cellular structure and require host cells to reproduce.
What is the main function of the nucleus in many cells?

It contains DNA and controls cell activities. The nucleus is the control center containing genetic material.
What is the correct classification of a virus based on cellular evidence alone?

Nonliving (not made of cells). Viruses lack cellular structure and can't reproduce independently.
Which structure is a thin boundary that surrounds all cells?

Cell membrane. It controls what enters and exits the cell.
What is the correct conclusion if a sample contains cytoplasm and ribosomes inside a membrane?

Living (cell components are present). These cellular components together indicate a living cell.
What cellular evidence can show that a dead organism was once living?

It still contains cells or cell structures. Dead cells retain their walls and internal structures as evidence.
What is the key difference between unicellular and multicellular organisms?

Unicellular have 1 cell; multicellular have many cells. The number of cells distinguishes these two organism types.
Which option is cellular evidence that a sample is animal tissue: cell wall absent or cell wall present?

Cell wall absent. Animal cells lack rigid walls, having only flexible membranes.
What is the cellular definition of a living thing used in life science?

A living thing is made of one or more cells. This is the fundamental criterion in biology for identifying life.
Which option is the best cellular evidence that an object was once living: fossilized cells or smooth glass?

Fossilized cells. Fossils preserve cell structures from once-living organisms.
What cellular feature is used to classify something as plant-like rather than animal-like?

A cell wall and chloroplasts. These structures enable photosynthesis and provide rigid support.
What organelle is a strong cellular clue that a sample is from a plant?

Chloroplast. Chloroplasts perform photosynthesis and are unique to plant cells.
Which option is living based on cellular evidence: a rock or a bacterium?

A bacterium. Bacteria are single-celled organisms; rocks have no cells.
What is the cell theory statement that connects cells to being alive?

All living things are made of one or more cells. This fundamental principle defines life at the cellular level.
Which option is a prokaryote: A) bacteria B) mushroom C) oak tree D) human?

A) Bacteria. Bacteria lack a nucleus, making them prokaryotic.
What cellular feature is the strongest evidence that something is living?

Presence of one or more cells. All living organisms must have at least one cell to carry out life functions.
What is the correct conclusion if you observe many cells arranged in layers in a sample?

It is living and likely multicellular. Multiple cells working together indicate a complex living organism.
What is the correct conclusion: A microscope view shows many repeating units with membranes; living or nonliving?

Living (cells are present). Membrane-bound units are cells, the hallmark of life.
Which option is the smallest unit of life: atom, molecule, cell, or tissue?

Cell. Cells are the basic units that make up all living organisms.
Which structure is present in plant cells but absent in animal cells and helps support shape?

Cell wall. This rigid structure provides extra support to plant cells.
What is the correct term for organisms whose cells lack a nucleus?

Prokaryotes. Their cells have no membrane-bound nucleus or organelles.
Which option is considered nonliving based on cellular evidence: A) virus B) bacterium C) paramecium D) fern?

A) virus. Viruses lack cellular structure and can't reproduce alone.
What is the correct conclusion if a microscope shows an object has cells with membranes and cytoplasm?

It is living or was once living. These structures are definitive proof of cellular organization.
Which option is a unicellular living thing: bacterium, granite rock, or plastic bead?

Bacterium. Bacteria are single-celled organisms, while rocks and plastic lack cells.
Which option is cellular evidence of life: cell membrane, crystal lattice, or metal alloy?

Cell membrane. Cell membranes are essential structures found only in living cells.
What is the cellular reason viruses are usually not classified as living?

They are not made of cells. Viruses require host cells and lack cellular structure.
Identify the correct conclusion: A sample shows no cells, only smooth mineral grains.

The sample is nonliving. Mineral grains lack cellular structure found in all living things.
Which option best describes a nonliving thing using cellular evidence?

It is not made of cells. Rocks, water, and synthetic materials lack cellular organization.
What is the term for an organism made of many cells?

Multicellular organism. Examples include plants, animals, and fungi like mushrooms.
What is the most reliable microscope-based rule for living vs nonliving classification?

If it has cells, it is living or once living. Cells are the universal characteristic that defines all life forms.
Identify the correct conclusion: a sample shows no cells and is only mineral crystals. Living or nonliving?

Nonliving. Minerals and crystals have ordered structures but no cells.
Which option is prokaryotic: A) bacterium B) yeast C) oak tree cell D) human cell?

A) bacterium. Bacteria lack nuclei and other membrane-bound organelles.
What is cytoplasm?

Jelly-like fluid inside a cell where many processes occur. This gel-like substance fills cells and holds organelles.
What is the function of cytoplasm in a cell?

Suspends cell parts and is the site of many reactions. The jelly-like substance fills the cell and enables chemical processes.
Which option is a eukaryotic cell: a plant cell or a bacterial cell?

A plant cell. Plant cells have a nucleus; bacterial cells are prokaryotic without one.
Which option is living based on cellular evidence: a virus or a bacterium?

A bacterium. Bacteria have cells; viruses lack cellular structure.
Which option is a cellular structure found in all cells: A) cell membrane B) nucleus C) chloroplast?

A) cell membrane. All cells need membranes; nuclei and chloroplasts are specialized.
Identify the correct classification by cells: a mushroom is living or nonliving?

Living. Mushrooms are fungi made of many cells.
What is a multicellular organism?

An organism made of many cells. Examples include all plants, animals, and fungi.
Which option is the best cellular evidence a material was once living: preserved cells or shiny surface?

Preserved cells. Dead organisms retain cellular structure; surface features don't.
Which type of microscope is typically used in middle school labs to view cells directly?

A compound light microscope. This microscope magnifies specimens enough to see individual cells.
Identify the correct conclusion: microscope shows many cells in a sample. Is it living?

Yes, it is living (it contains cells). Presence of cells is definitive proof of a living organism.
Which option is once-living based on cellular evidence: a wooden desk or a plastic chair?

A wooden desk. Wood contains dead plant cells from the tree it came from.
Which option is cellular evidence that something was once living: A) cell walls B) magnetism C) boiling point?

A) cell walls. Cell walls persist after death; magnetism and boiling point aren't cellular.
Which option is living based on cellular evidence: yeast cells in water or salt crystals?

Yeast cells in water. Yeast are single-celled fungi that show cellular structure.
Which option is nonliving based on cellular evidence: fire or algae?

Fire. Fire is a chemical reaction without cells; algae are living organisms.
Identify the correct conclusion: a sample contains many cells organized into tissues. Living or nonliving?

Living. Tissue formation indicates multicellular life.
What is the correct cellular classification of a virus in middle school life science?

Nonliving by cellular evidence (not made of cells). Viruses lack cellular structure despite having genetic material.
What is the function of the cell membrane in living things?

Controls what enters and leaves the cell. This selective barrier maintains the cell's internal environment.
What cell structure is the thin outer boundary that encloses the cytoplasm in all cells?

Cell membrane. This protective barrier controls what enters and exits the cell.
Which option has cells: a plastic bead or a leaf?

A leaf. Leaves contain plant cells; plastic is synthetic without cells.
What is the cellular evidence that most reliably shows something is living?

Presence of one or more cells. All living organisms are composed of at least one cell.
Which option is once-living based on cellular evidence: paper or aluminum foil?

Paper. Paper is made from plant fibers that once had living cells.
Identify the correct conclusion: a sample is made of cells but the cells are no longer alive; is the sample living now?

Nonliving now, but it was once living. Dead cells cannot perform life processes, making the sample nonliving.
Which option is cellular evidence of a plant cell: chloroplast, centriole, or none?

Chloroplast. Only plant cells contain chloroplasts for photosynthesis.
Identify the correct conclusion: A dried leaf still shows cell walls under a microscope; living or nonliving now?

Nonliving now (but once living). Dead organisms retain cellular structures but lack life processes.
What cellular structure contains genetic material in eukaryotic cells?

Nucleus. Controls cell activities and stores DNA in membrane-bound compartment.
What cellular criterion is sufficient to classify something as living?

Presence of one or more cells. All living things are made of at least one cell.

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