Cells

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StandardsEssential QuestionsCell TheoryProkaryotes and EukaryotesProkaryotic CellsEukaryotic CellsPlants vs. AnimalsEukaryotic Cells (Plants)Cell Assessment

STANDARDSBenchmark: SC.912.L.14.1 – Describe the scientific theory of cells (cell

theory) and relate the history of its discovery to the process of science.

SC.912.L.14.3 – Compare and contrast the general structures of plant and animal cells.

SC.912.L.14.2 – Relate structure to function for the components of plant and animal cells.

ESSENTIAL QUESTIONSBenchmark: What is the scientific theory of cells (cell theory) and what is the

history of its discovery? What are the general structures of plant and

animal cells and how are they the same and different

What are the functions of the different organelles in animal and plant cell?

CELL THEORY In 1665, Robert Hooke used an early compound microscope

to look at a thin slice of cork In 1675, Anton van Leeuwenhoek became the first person to

observed living cells In 1831, Robert Brown identifies a structure within the cells

that he terms the "nucleus." In 1838, Matthias Schleiden concludes that all plants are

made up of cells In 1839, Theodor Schwann concludes that all animals are

made up of cells In 1855, Rudolf Virchow stated that all cells come from the

division of preexisting cells

CELL THEORY All living things are composed of single cells

or multiple cells. The cell is the basic unit of living things. All cells arise from pre-existing cells.

Mathias Schleidan

Anton van Leeuwenhoek

Robert Hooke

Robert Brown

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Rudolf Virchow

PROKARYOTIC & EUKARYOTIC

Prokaryotic vs. Eukaryotic Cells

Cells fall into two broad categories, depending on whether they contain a nucleus Eukaryotes are cells that contain nuclei and membrane-bound organelles Eu- means true - karyote means nucleus

Prokaryotes are cells that do not contain nuclei and organelles membrane-bound Pro- means before - karyote means nucleus

EukaryoteProkaryote

PROKARYOTIC & EUKARYOTIC

EukaryoteProkaryote

Nucleus is absent No membrane-bound

organelles Most 1-10 um in size Evolved 3.5 billion years ago Only unicellular bacteria and

archaebacteria

Nucleus is present Many membrane-bound

organelles Many 2-1000um in size Evolved 1.5 billion years ago All other cells (animal, plant,

fungi, and protist)

PROKARYOTIC CELL Prokaryotic Cell Structures

Prokaryotes do not have a membrane-bound nucleus.

DNA is distributed loosely within the cell rather than in chromosomes.

EUKARYOTIC CELL Eukaryotic Cell Structures

Structures within a eukaryotic cell that perform important cellular functions are known as organelles.

Cell biologists divide the eukaryotic cell into two major parts: the nucleus and the cytoplasm.

The cytoplasm is the portion of the cell outside the nucleus.

EUKARYOTIC CELL Nucleus

• The nucleus is the control center of the cell.

• The nucleus contains nearly all the cell's DNA and with it the coded instructions for making proteins and other important molecules

EUKARYOTIC CELL Ribosomes

• One of the most important jobs carried out in the cell is making proteins.

• Proteins are assembled on ribosomes.

• Ribosomes are small particles of RNA and protein found throughout the cytoplasm.

• Ribosomes produce proteins by following coded instructions that come from the nucleus.

• Cells that are active in protein synthesis are often packed with ribosomes

EUKARYOTIC CELL Endoplasmic Reticulum

Eukaryotic cells contain an internal membrane system called the endoplasmic reticulum, or ER.

The endoplasmic reticulum is where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell.

Ribosomes

Endoplasmic Reticulum

EUKARYOTIC CELL Golgi Apparatus

• Proteins produced in the rough ER move into the Golgi apparatus.

• The Golgi apparatus appears as a stack of closely apposed membranes

Golgi Apparatus

EUKARYOTIC CELL Lysosomes

Lysosomes are small organelles filled with enzymes.

Lysosomes break down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell.

Lysosomes also break down organelles that have outlived their usefulness

EUKARYOTIC CELL Mitochondria

Nearly all eukaryotic cells contain mitochondria.Mitochondria convert the chemical energy stored in food into compounds that are more convenient for the cell to use.

Mitochondria

PLANTS VS. ANIMAL CELLA plant cell has a cell

wall for support and protection.

Animal cells don't have chloroplasts. Plant cells have thylakoids that are sites of photosynthesis chemical reactions.

Lysosomes usually not evident in plant cells.

PLANTS VS. ANIMAL CELLTypical Animal CellTypical Plant Cell

PLANTS VS. ANIMAL CELLTypical Animal CellTypical Plant Cell

Animal Cell Plant Cell

Nucleus: Present Present

Cilia: Present It is very rare

Shape: Round (irregular shape) Rectangular (fixed shape)

Chloroplast: Animal cells don't have chloroplasts

Plant cells have chloroplasts because they make their own food

Cytoplasm: Present Present

Endoplasmic Reticulum (Smooth and Rough):

Present Present

Ribosomes: Present Present

Mitochondria: Present Present

Vacuole: One or more small vacuoles (much smaller than plant cells).

One, large central vacuole taking up 90% of cell volume.

Centrioles: Present in all animal cells Only present in lower plant forms.

Plastids: Absent Present

Golgi Apparatus: Present Present

Cell wall: Absent Present

Plasma Membrane: only cell membrane cell wall and a cell membrane

Microtubules/ Microfilaments:

Present Present

Flagella: May be found in some cells May be found in some cells

Lysosomes: Lysosomes occur in cytoplasm. Lysosomes usually not evident.

EUKARYOTIC CELL Chloroplasts

Plants and some other organisms contain chloroplasts.

Chloroplasts capture energy from sunlight and convert it into chemical energy in a process called photosynthesis. Chloroplasts

EUKARYOTIC CELL Vacuoles

Some cells contain saclike structures called vacuoles that store materials such as water, salts, proteins, and carbohydrates.

Vacuole

CELL ASSESSMENT1. In 1675, Anton van Leeuwenhoek became the first person to observe living cells. He reported discovering "little animals" -- bacteria and protozoa.Which part of the cell theory is best supported by this discovery?

A. All cells are animal or fungiB. All cells are the same microscopic size -10 micrometers.C. The cell is the basic unit of living things.

D. All cells reproduce by meiosis.

2. There are many types of cellular life forms on Earth. But, generally speaking there are two major types of cell structures.

A. Prokaryotes and bacteriaB. Prokaryotes and eukaryotesC. Fungi and PlantaeD. Eukaryotes and bacterium

CELL ASSESSMENT3. Plants, Fungi and animals share many similar characteristics, but not all organisms can make their own food. Which organisms make their own food? .

A. Fungi and plants can make their own food by photosynthesis.B. Only fungi can actually make their own food.C. Plants can make their own food with the help of symbiotic bacteria.

D. Organisms with chloroplasts can make their own food.

4. Organisms that reproduce by replicating DNA in the nucleus and by cytokinesis must be which type of cells?

A. Only animals cell replicate the nucleus.B. The cells must be eukaryotes, because they have a nucleusC. The cells must be prokaryotes, because they have a nucleusD. Only fungal reproduction uses cytokinesis.

CELL ASSESSMENT5. The cell theory states that cells come from existing cells. What theory states that life comes from non-living matter?

A. Mackey-Creation TheoryB. The Supernatural Genesis TheoryC. The theory is called abiogenesis or spontaneous generation.

D. The Rotting Meat-Maggot Theory

6. Plants have organelles that use sunlight to enable photosynthesis that eventually produce “sugars”. What else do plants need to produce their “sugars”?

A. Plants also need water, carbon dioxide, nitrogen and minerals.B. Plants need oxygen, water and soil.C. Plants can make all they need from the suns radiation and water.D. Plants need light, water and Chlorophyll

CELL ASSESSMENT7. Plants have organelles that use sunlight to enable photosynthesis that eventually produce “sugars”. What is the name of the organelle?

A. The organelles is called the sucrose engineB. The organelle is called the chloroplastC. The Calvin-Krebs apparatusD. The organelle is called the chlorophyll

8. In 1831, Robert Brown identifies a structure within the cells that he terms the "nucleus.“ The nucleus is an important organelle in eukaryotic cells. What is the function of the nucleus?

A. The nucleus is the “brain” of the cell. It decides all activities in a cell.B. The nucleus is the control center of the cell.C. The nucleus only replicates DNA for cell division.D. The nucleus is only found in prokaryotic cells.

CELL ASSESSMENT9. Proteins determine almost every activity in a cell. Where are proteins assembled?

A. Proteins are assembled by the cell cytoplasm.B. The Golgi Apparatus assembled the protein in animal and plant cells.C. All proteins are assembled by the DNA in the nucleus.

D. Proteins are assembled on ribosomes.

10. Plant cells share many characteristics of animal cells, but they usually do not have all the same organelles. What are some differences between plant and animal organelles?

A. Plants have chloroplasts, cell walls, plastids and much greater

vacuoles than animal cellsB. Plants have leaves, stems and are tripedic.C. Plants are heterotrophsD. Animals have Golgi apparatus.

CELL ASSESSMENT

Following are the Biology Assessment with answers for cells as determined by Ms. Donohue.

Including:

BASELINEWINTERFALL

CELL BASELINE1. Robert Hooke is credited with discovering cells while observing a piece of cork under a microscope. In his book Micrographia, which he published in 1665, Hooke describes the small structures that he observed under the microscope. Which part of the cell theory is best supported by this discovery?

A. Cells perform specialized functions.B. The cell is the basic unit of living things.C. All organisms are made of one or more cells.D. Cells reproduce and all cells come from existing cells.

3. How is a plant cell different from an animal cell?A. An animal cell has a cell membrane that allows certain substances to pass through.B. An animal cell has a central vacuole for storing materials.C. A plant cell has a cell wall for support and protection.D. A plant cell has ribosomes for assembling proteins.

4. Bacteria are prokaryotic cells. By contrast, animal, plant, and fungal cells are eukaryotic. What is the main difference between prokaryotes and eukaryotes?

F. Eukaryotes have a cell wall.G. Prokaryotes cannot live without a host.H. Eukaryotes copy DNA and are able to reproduce.I. Prokaryotes do not have a membrane-bound nucleus.

7. Which piece of scientific knowledge best supports the idea of the cell theory that cells come from existing cells?

A. Cells are the smallest structures that carry out specialized functions in a living organism.B. Multicellular organisms have chromosomes located in membrane-bound nuclei.C. Some members of a species display a trait due to mutations in genetic coding.D. Chromosomes are copied during the replication process.

CELL BASELINE

10. In the 1800s, scientists studied how fat-soluble substances and water-soluble substances interact with cell membranes. Their studies provided evidence that cell membranes are structured to perform certain functions. What function did these studies suggest that cell membranes perform?F. control the cell's activitiesG. control which substances enter the cellH. form proteins from fat-soluble substancesI. carry materials throughout the interior of the cell 19. A large area of farmland has many different species of insects living on it. Most of these insects arepollinators of the crops that grow on the farm. If the farmer decides to plant one crop on all his plots, what will be the result?A. There will be less insect diversity.B. The crops will be more likely to survive.C. The crops will undergo genetic mutations.D. The different insect species will interbreed. 46. What is one of the main advantages of asexual reproduction?F. It occurs more slowly than sexual reproduction.G. There is a smaller chance of mutation.H. The offspring varies from the parent.I. It creates more genetic variety.

CELL FALL

1. What method did Theodor Schwann use to verify his hypothesis that all living things are composed of cells?A. He tried to grow an organism from a single cell.B. He studied literature on the development of cell theory.C. He built a model of a cell he saw in one type of organism.D. He used microscopes to examine the tissues of many different organisms.

3. Which of the following accurately states a difference between plant and animal cells?A. Animal cells have stomata that allow for the exchange of gases.B. Plant cells have thylakoids that are sites of chemical reactions.C. Plant cells have stromal cells that make up connective tissue.D. Animal cells have chloroplasts that turn glucose into ATP.

4. If you examined a cell under a microscope and found it had a nucleus and other organelles, how would you classify the cell?F. It is a plant cell.G. It is an animal cell.H. It is a eukaryotic cell.I. It is a prokaryotic cell.

7. In the past, some scientists accepted the theory of spontaneous generation. This theory states that organisms can arise from nonliving matter. Now scientists generally accept cell theory to explain the origin and growth of new organisms. Which of these statements is a key idea of cell theory that disproves the theory of spontaneous generation?A. The cell is the basic unit of life.B. All living things are made of matter.C. All cells arise from pre-existing cells by division.D. All cells are formed from the combination of two other cells.

CELL FALL

10. Bacteria are prokaryotic cells, while multicellular and more sophisticated single-celled organisms are eukaryotic. Which of these describes a prokaryotic cell and NOT a eukaryotic cell?F. Sunlight is absorbed by chloroplasts in the cell.G. Molecules join together to assemble a permeable cell membrane.H. The nuclear membrane disassembles and chromosomes align in a cell.I. DNA is distributed loosely within the cell rather than in chromosomes.

14. After the invention of the microscope, biologists were able to look at organisms on a microscopic scale. The new data that they collected with this instrument led to what theory?F. cell theoryG. atomic theoryH. theory of inheritanceI. theory of organic evolution

17. The diagrams below show an example of a prokaryote and a eukaryote.Which statement is true for both prokaryotes and eukaryotes?A. They can only reproduce asexually.B. Their DNA is found within a nucleus.C. Their DNA is found within the mitochondria.D. Their DNA is replicated during reproduction.

18. Because the function of most plant leaves is to carry out photosynthesis, their cells contain many more of what organelle than the other parts of the plant?F. chloroplastsG. mitochondriaH. nucleiI. vacuoles

CELL WINTER

1. Living organisms include bacteria, fungi, plants, and animals. What is one thing that all living things have in common?A. They are all made of multiple cells.B. They all result from replication of pre-existing cells.C. They all perform cell division to decrease the surface-area to volume ratio.D. They all start as single-celled organisms and become multicellular through replication.

3. Different types of cells can have certain organelles and structures in common. Which types of cellsdefinitely contain cell walls?A. plant and animal cellsB. plant and eukaryotic cellsC. plant and prokaryotic cellsD. animal and eukaryotic cells

4. Cells are classified as either prokaryotic or eukaryotic according to differences in their structure. However, these cells also share several traits. Which of the following may be found in all prokaryotic and eukaryotic cells?F. nucleusG. cell wallH. chloroplastsI. plasma membrane

CELL WINTER

7. Jamie is observing three different prepared slides under a light microscope. The pictures below show what she sees.

Which of the following can Jamie offer as evidence that supports the cell theory, based on these slides?

A. All cells come from parent cells that exchange DNA.B. All living things are composed of single cells or multiple cells.C. All cells grow and develop until they reach a certain size, at which point they die.D. All cells are equipped with structures that enable motion, such as pseudopods or flagella.

10. The diagram below shows two kinds of cells.

A biologist wants to classify protein secretions into groups based on the principal function of the protein.Which cell would the biologist select to study and why?

F. The cell on the left, because it has genetic information organized into chromosomes.G. The cell on the left, because it has organelles that secrete proteins.H. The cell on the right, because it has free proteins throughout its cytoplasm.I. The cell on the right, because it has a flagellum that enables movement.

CELL WINTER

22. The diagrams below show an example of a prokaryote and a eukaryote .

The eukaryote shown above is a one-celled organism. Into which group should it be classified?F. domain ArchaeaG. domain BacteriaH. kingdom ProtistaI. kingdom Animalia

30. In 1966, Dr. Lynn Margulis formulated the endosymbiotic theory, which examines the cooperativeexistence of multiple prokaryotic organisms. What is the significance of such interdependence?F. It shows that the first prokaryotic organisms lived in large communities.G. It explains how organelles and eventually eukaryotic cells could have arisen.H. It proves that different prokaryotic organisms mated to produce eukaryotic organisms.I. It provides insight into the now well understood interdependence in food chains and webs.

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