Y3 Bio Topic 1 Flashcards
What is the basic unit of life?
Cell
Who coined the term “cell”?
Robert Hooke (1662)
Who was the first to observe plant and animal cells with a microscope?
Antony van Leeuwenhoek
What are the three main tenets of the cell theory?
1) All living organisms are composed of cells. 2) The cell is the basic unit of life. 3) All cells arise from pre-existing cells.
Who proposed that plants and animals are made of cells?
Matthias Schleiden (plants) and Theodor Schwann (animals)
What did Rudolf Virchow contribute to cell theory?
He stated that all cells arise from pre-existing cells.
What is the size range of most cells?
1-100 micrometers (µm)
What type of microscope would you use to observe live cells?
Light microscope
What is the maximum magnification of a light microscope?
1000–1500x
What type of microscope provides the highest magnification and resolution?
Electron microscope
What are the two main types of electron microscopes?
Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM)
What is the resolving power of an electron microscope?
Around 0.2 nanometers (nm)
What are the three domains of life?
Bacteria, Archaea, and Eukarya
What are the six kingdoms of life?
Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia
How do prokaryotic and eukaryotic cells differ?
Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have both.
Give an example of a prokaryotic organism.
Escherichia coli (E. coli)
What is a key structural feature of bacterial cell walls?
They contain peptidoglycan.
What is a key structural feature of Archaea cell walls?
They lack peptidoglycan and have unique lipid structures.
What are the two major regions of a eukaryotic cell?
Nucleus and cytoplasm
What is the function of the nucleus?
Contains DNA and controls cell activities.
What are chromatin threads?
Long, thread-like structures of DNA found in the nucleus.
What happens to chromatin during cell division?
It condenses to form visible chromosomes.
What is the function of the nucleolus?
Produces ribosomes.
What is the function of the mitochondria?
Generates ATP through cellular respiration.
Why do muscle cells contain many mitochondria?
They require large amounts of energy for contraction.
What is the function of ribosomes?
Synthesizes proteins.
Where are ribosomes found?
In the cytoplasm or attached to the rough endoplasmic reticulum (RER).
What is the function of the rough endoplasmic reticulum (RER)?
Transports proteins synthesized by ribosomes.
What is the function of the smooth endoplasmic reticulum (SER)?
Synthesizes lipids and detoxifies harmful substances.
What is the function of the Golgi apparatus?
Modifies, packages, and transports proteins and lipids.
What is the function of lysosomes?
Digest waste materials and cellular debris.
What is the function of the cell membrane?
Controls the movement of substances in and out of the cell.
What is the main structural component of the cell membrane?
Phospholipid bilayer.
What is the function of chloroplasts?
Conducts photosynthesis in plant cells.
What pigment is found in chloroplasts?
Chlorophyll.
What is the function of the vacuole in plant cells?
Stores nutrients and maintains turgor pressure.
What is the function of the cytoskeleton?
Provides structural support and facilitates cell movement.
What organelle is found only in plant cells?
Chloroplast.
What organelle is found only in animal cells?
Centrioles.
What is the main carbohydrate storage molecule in plants?
Starch.
What is the main carbohydrate storage molecule in animals?
Glycogen.
What is cell differentiation?
The process by which a cell develops a specific structure and function.
How is a red blood cell adapted to its function?
It has a biconcave shape to increase surface area for oxygen transport.
Why does a red blood cell lack a nucleus?
To allow more space for hemoglobin.
What is the function of a nerve cell (neuron)?
Transmits electrical impulses.
How is a muscle cell adapted to its function?
Contains many mitochondria to supply energy for contraction.
How is a root hair cell adapted for absorption?
Has an extended surface area for better water and mineral uptake.
What is a tissue?
A group of similar cells that perform a specific function.
Give an example of a tissue.
Muscle tissue.
What is an organ?
A structure made up of different tissues that perform a function.
Give an example of an organ.
Stomach.
What is an organ system?
A group of organs working together to perform a function.
Give an example of an organ system.
Digestive system.
