Chapter 7 - Cells Flashcards
Who was the first person to discover cells of any kind?
Robert Hooke discovered non-living cells in 1665.
Who was the first person to discover living cells?
Anton van Leeuwenhoek examined pond water and other samples including one from a human mouth. He was the first to see living cells, bacteria.
Who concluded that plants are made of cells?
Matthias Schleiden concluded that plants are made of cells.
Who stated that new cells could be produced only from the division of existing cells?
Rudolf Virchow stated that new cells could be produced only from the division of existing cells.
Who stated that all animals are made of cells?
Theodor Schwann stated that all animals are made of cells.
How do microscopes work?
Most microscopes use lenses to magnify the image of an object by focusing lights or electrons.
What are the three points of cell theory?
- All living things are made of cells
- Cells are the basic units of structure and function in living things
- New cells are produced from living cells
Where did Leeuwenhoek first discover cells and what did they call them?
Leeuwenhoek first discovered cells in water and called them “animalcules”.
What is the difference between light microscopes and electron microscopes?
Light microscopes allow light to pass through a specimen and uses 2 lenses to magnify an image. Electron microscopes use a beam of electrons rather than light.
What type of electron microscope produces a two-dimensional image?
Transmission electron microscopes produce flat, two-dimensional images.
What type of electron microscope produces three-dimensional images?
Scanning electron microscopes produce three-dimensional images.
What is the difference between prokaryotes and eukaryotes?
Prokaryotic cells do not contain a nucleus.
What are some examples of prokaryotic and eukaryotic cells?
An example of a prokaryotic cell is bacteria, like E. coli. An example of eukaryotic cells are plants and animals.
How and why are all cells different?
All cells differ in shape and size because they preform different functions.
What is the function of a nucleus?
The nucleus is large membrane-enclosed structure that controls many of the cell’s activities. It contains nearly all of the cell’s DNA.
What is the function of the Golgi apparatus?
The Golgi apparatus packages proteins and ships them where they need to go.
What is the function of a lysosome?
Lysosomes are small organelles filled with enzymes that removes junk that would otherwise clutter up the cell. They also break down organelles that have outlived their usefulness.
What is the function of an endoplasmic reticulum?
An endoplasmic reticulum’s responsibility is assembling lipids and proteins.
What is the function of a mitochondrion?
A mitochondrion converts the chemical energy stored in food into compounds that are more convenient for the cells to use.
What is the function of a cytoskeleton?
The cytoskeleton helps the cell maintain its shape and is involved in movement.
What is the function of a vacuole?
A vacuole stores material like water, salts, proteins, and carbohydrates.
What are the functions of ribosomes?
Ribosomes form proteins.
What is the function of a chloroplast?
Chloroplasts capture solar energy and convert it into food that contains energy in a process called photosynthesis.
What is the function of the cell wall?
The cell wall is found only in plants and it provides support, protection, and shade.
What function of the cell membrane?
The cell membrane regulates what enters and leaves the cell.
What is a channel protein?
A channel protein is a protein that allows the transport of specific substances across a cell membrane.
What are some of the main differences between plant and animal cells?
Only plant cells have cell walls. Plant cells have one, large central vacuole as opposed to the animal cell’s multiple, smaller ones. Chloroplasts are only found in plant cells.
What are cell membranes made of?
Cell membranes are composed of a lipid bilayer. (2 layers of lipids)
What’s the difference between the nucleus and the nucleolus?
The nucleolus is a spherical structure located inside the nucleus. The nucleolus is where ribosomes are assembled.
What is the smallest part of any living thing that is considered alive?
Cells are the smallest part of any living thing that are considered alive.
Why does the specimen have to be thin for a microscope?
If a specimen is too thick, light cannot pass through.
What do you do when living cells are transparent and the structures within them cannot be seen?
Chemical stains or dyes are used when living cells are transparent.
What are the two broad categories that all cells fall into?
All cells are either prokaryotic or eukaryotic.
What gives coded instructions to the rest of the cell?
DNA gives coded introductions to the rest of the cell.
Which cell category is generally larger and more complex?
Eukaryotic cells are generally larger and more complex. They are highly specialized and contain dozens of structures and internal membranes.
What is cytoplasm?
Cytoplasm is the fluid portion of the cell outside the nucleus.
What are organelles?
Organelles are cellular structures that act as specialized organs.
Where is DNA located?
The nucleus contains nearly all the cell’s DNA.
What is the nuclear envelope?
The nuclear envelope surrounds the nucleus and is dotted with nuclear pores, which allow material to move into and out of the nucleus.
What are chromosomes?
Chromosomes contain genetic info. They condense when their cell divides.
Where are ribosomes assembled?
Ribosomes are assembled in the nucleolus.
What are vesicles?
Vesicles store and move materials between cell organelles.
Why are ERs called smooth and rough?
The smooth ER does not have ribosomes on its surface.
Where is the ER located?
Eukaryotic cells contain an internal membrane system known as the endoplasmic reticulum .
What is the chlorophyll and where is it located?
The chlorophyll is a green pigment in plant cells. They are located inside the thylakoid membranes.
What does it mean to be selectively permeable?
Most biological membranes are selectively permeable, meaning that some substances can pass across them and others cannot.
What are cells named after?
The namesake of the cell comes from the cells that monks stay in.
