Cells

Question 1

What is the name for the study of all aspects of a cell?

Answer 1

Cytology

Question 2

What does cell theory state?

Answer 2

• All organisms are made up of one or more cells
• Cells are the smallest units of life
• All cells come from pre-existing cells

Question 3

Who were the first people to “observe” cells?

Answer 3

• Robin Hooke 1665, homemade microscope, looking at cork
• Antonie Van Leeuwenhoek few years later, living cells, animalcules (little animals)
• Matthias Schleiden 1838, “plants made of independent, separate beings called cells”
• Theodor Schwann 1839, similar statement as ^, but animals

Question 4

What did Louis Pasteur do?

Answer 4

In the 1880s, he performed experiments with chicken broth. He sterilized it by boiling it and showed that living things did not spontaneously appear.

Question 5

Which statement of the cell theory did Pasteur’s experiment’s results support?

Answer 5

The statement about how all cells come from pre-existing cells.

Question 6

What are the functions of life?

Answer 6

• Metabolism (chemical reactions, respiration)
• Excretion
• Reproduction
• Growth
• Response to surroundings
• Homeostasis
• Nutrition

Question 7

What is Paramecium?

Answer 7

A unicellular organism belonging to the kingdom known as Protista. Eats by engulfing

Question 8

What are some traits of the light microscope?

Answer 8

• Relatively cheap
• Can observe living things
• Can see color
• Magnifies up to 2000x

Question 9

What are some traits of the electron microscope?

Answer 9

• Expensive
• Magnifies up to 500 000x
• Specimens are dead (vacuum?)

Question 10

What are the relative sizes of cells and their sub units?

Answer 10

Cells are relatively big, then organelles, then bacteria, then viruses, membranes, and molecules

Question 11

How do you calculate magnification?

Answer 11

Total magnification=size of image/size of specimen

Question 12

Why are cells not infinitely big?

Answer 12

Surface area to volume ratio

Question 13

How does an organism develop?

Answer 13

Usually begins as a single cell after sexual reproduction. Then the cell divides and differentiates for different cell types. The type is based on which genes become active

Question 14

What happens after differentiation?

Answer 14

Cells are specialized with only a segment of DNA being active (although they do contain all of the DNA), some might also lose ability to reproduce like muscle or nerve cells. If they do keep reproducing, the offspring will differentiate into same cell types as parents

Question 15

What are emergent properties?

Answer 15

The whole is more than the sum of its parts. Each cell does their job in addition to interacting with other cells to perform other functions

Question 16

What are stem cells?

Answer 16

Cells that can differentiate and become any other cell

Question 17

What is the difference between pluripotent stem cells and tissue-specific stem cells?

Answer 17

Pluripotent stem cells (embryonic stem cells) can differentiate into any other type of cell while tissue-specific stem cells reside in one type of tissue and can only become cells of the same type of tissue.

Question 18

What is Stargardt’s disease?

Answer 18

A recessive, inherited disease caused by a gene that codes for a defect in production of Vitamin A. Vitamin A is needed for light-sensitive cells in the retina to function. A person with Stargardt’s disease will start losing their central vision within the first 20 years of their life, then they begin losing peripheral vision and they eventually become blind

Question 19

What are some examples of stem cell treatment?

Answer 19

• Tissue-specific blood stem cells are used to treat leukemia by replacing the damaged bone marrow
• Pluripotent stem cells are starting to be used as treatment for Stargardt’s disease to protect and regenerate photoreceptors in the retina

Question 20

What is the size of most prokaryotic cells?

Answer 20

Between 1 and 10 micro meters in diameter

Question 21

What is the prokaryotic cell wall made of?

Answer 21

In most prokaryotes the cell wall is composed of a carbohydrate-protein complex called peptidoglycan. Some bacteria also have a polysaccharide outside the cell wall to adhere to stuff

Question 22

Where is the cell membrane in relation to the cell wall?

Answer 22

The membrane is inside the cell wall

Question 23

What are the organelles of prokaryotic cells?

Answer 23

• Capsule (to adhere to stuff)
• Cell wall (protection and structure)
• Cell membrane (regulates import and export)
• Cytoplasm (many reactions happen here)
• Ribosomes (protein synthesis)
• Nucleoid (hereditary information (one chromosome), controls cell activity, reproduction)
• Plasmid (small ring of DNA with specific genes)
• Pili (attachement (mostly to other bacteria))
• Flagellum (movement)

Question 24

What is binary fission?

Answer 24

The way in which bacteria reproduce. Very similar to mitosis except there is no nuclear membrane or centrioles and there is only one chromosome that replicates itself

Question 25

In what kind of organisms can eukaryotic cells be found?

Answer 25

• Algae
• Protozoa
• Fungi
• Plants
• Animals

Question 26

What are the organelles in a eukaryotic cell?

Answer 26

• Some have cells walls (plants have cellulose, structure and protection)
• Plasma membrane (regulates import and export)
• Cytoplasm (where reactions take place)
• Mitochondria (carry out respiration)
• Centrioles (only animals(?), made of microtubules, found in centrosome (area), play a role in cell division)
• Nuclear membrane (keeps nuclear stuff inside nucleus)
• Lysosomes (digestive enzymes (transport or contain), usually absent in plants)
• Vacuoles (sacs of water)
• Smooth ER (lipid synthesis (steroids))
• Rough ER (proteins for export)
• Ribosomes (protein synthesis)
• Nucleolus (ribosome synthesis)
• Nuclear pore (allows communication between nucleus and rest of cell)
• Golgi apparatus (stores, modifies and packages proteins for export)
• Chromatin (regions of nucleus containing DNA and histones)
• Secretory vesicles (protein inside a membrane that is leaving the cell)
• Phagocytic vesicles (sacs with food)
• Pinocytic vesicles (sacs with water)
• Cytoskeleton (consists of microtubules (hollow fibres that can be made or broken down as needed, internal support) and microfilaments (long thin threads, move structures within cell which helps movement of whole cell))

Question 27

What are some structures that plant cells have that animals do not?

Answer 27

• Cell wall made of cellulose
• Middle lamella (sticky thing that holds cell walls together with other cell walls)
• Chloroplast (site of photosynthesis)
• Plasmodesmata (thin thread of cytoplasm that link adjacent cells and allow exchange of materials)

Question 28

What is the size of eukaryotic cells?

Answer 28

10-100 micro meters

Question 29

What does compartmentalization in cells mean?

Answer 29

Eukaryotic cells have membrane bound organelles, this enables different chemical reactions to be separated and specific reactions can be isolated, this leads to an increased efficiency