Biology C1/2

Question 1

Cell Theory

Answer 1

1) All living things are made up of one or more cells
2) Cells are the smallest functional unit of life
3) All cells are produced by the division of other pre-existing cells

Question 2

Robert Hooke

Answer 2

The first person to observe and describe cells

Question 3

Antonie van Leeuwenhoek

Answer 3

Observed the first living cells and called them “animalcules”

Question 4

Botanist Matthias Schleiden

Answer 4

Stated that plants were made up of cells

Question 5

Zoologist Theodor Schwann

Answer 5

Stated that animals were made up of cells

Question 6

Robert Brown

Answer 6

Discovered the nucleus in plant cells

Question 7

Francesco Redi

Answer 7

Disproved the theory of spontaneous generation

Question 8

Louis Pasteur

Answer 8

Proved beyond a reasonable doubt that spontaneous generation of life does not now occur

Question 9

Rudolph Circhow

Answer 9

Observed cells dividing and stated that new cells are formed by the division of pre-existing cells

Question 10

Light Microscope

Answer 10

Visible light is passed through a specimen, and then one (simple) or two (compound) glass lenses. The lenses refract the light

Question 11

Transmission Electron Microscope

Answer 11

A beam of electrons is passed through a very thin section and electrons that pass through fall on photographic film - produces clear images of interior

Question 12

Scanning Electron Microscope

Answer 12

Electrons reflected off a specimen covering with an electron-dense material (gold) - produce 3-D image of the surface

Question 13

Prokaryotic Cells

Answer 13

• Smaller than eukaryotic cells
• Lack membrane-bound organelles
• Earth’s first inhabitants

Question 14

Eukaryotic Cells

Answer 14

• Larger than prokaryotic cells
• Have a true nucleus and membrane-bound organelles\
• Evolved from prokaryotic cells
• Involves animal and plant cells

Question 15

Organelles

Answer 15

Membrane-bound structures inside eukaryotic cells that have specialized functions

Question 16

Cell Wall

Answer 16

Rigid outer layer made up of cellulose that maintains the cell’s shape and protects the cell from mechanical damage. Only in plant cells.

Question 17

Cell Membrane

Answer 17

Flexible phospholipid bilayer surrounding the cell, that serves as a selectively permeable barrier between he inside and outside of the cell

Question 18

Cytoplasm

Answer 18

A semifluid, jellylike substance containing dissolved substances, in which organelles and other components are found

Question 19

Nucleus

Answer 19

Contains the DNA, and directs all cellular activity. Densely stained part is nucleolus, where ribosomes are produced

Question 20

Nuclear Envelope

Answer 20

Double-membrane surrounding the nucleus, that has nuclear pores to allow transport to allow transport of materials into and out of the nucleus

Question 21

Ribosomes

Answer 21

Small complexes that translate genetic information (DNA) into proteins

Question 22

Rough Endoplasmic Reticulum (Rough ER)

Answer 22

Studded with ribosomes and packages and transports secretory protein. Connected with the nucleus

Question 23

Smooth Endoplasmic Reticulum (Smooth ER)

Answer 23

Not studded with ribosomes, synthesizes lipids and packages them for transport to other parts of the cell

Question 24

Golgi Apparatus

Answer 24

Recieve transport vesicles from the ER. ER products are modified and stored, then sorted, repackaged, and shipped to other destinations in the cell

Question 25

Lysosomes

Answer 25

Membrane sacs containing digestive enzymes within an acidic environment. Used to breakdown food particles, kill infectious micro-organisms, and to recycle damaged or worn-out cell parts. Only in animal cells

Question 26

Vacuoles

Answer 26

Membrane-bound sacs used for storage of food, water, mineral, and other substances. Plants have a large central vacuole that is important for storage and water regulation

Question 27

Mitochondria

Answer 27

Has 2 membranes, the inner being highly folded. Where cellular respiration occurs to generate ATP

Question 28

Chloroplasts

Answer 28

Has 2 membranes, containing flattened membranous sacs with chlorophyll. Where photosynthesis occurs, converting light energy into chemical energy

Question 29

What is the plasma membrane made out of

Answer 29

The plasma membrane is composed of phospholipids, proteins, carbohydrates, and cholestrol

Question 30

Phospholipids

Answer 30

- Have a phosphate head and two fatty acid tails - Phosphate head is hydrophilic (polar) Face out toward watery fluid - Fatty acid tails are hydrophobic (non-polar) Face in toward interior of bilayer away from the water

Question 31

Proteins

Answer 31

- Can be embedded in or attached to the phospholipid bilayer - Transports specific substances into or out of the cell

Question 32

Fluid Mosiac Model

Answer 32

- States that the membrane is a "fluid" structure with a "mosiac" of various proteins embedded in or attached to a bilayer of phospholipids - Fluid because the components of the membrane are in constant motion - Mosiac because proteins are embedded in the phospholipid bilayer

Question 33

Cell Membrane Function

Answer 33

1) Gives shape and structure to the cell 2) Acts as a biological barrier, separating and protecting the cell from its surroundings 3) Regulates the movement of substances into and out of the cell

Question 34

Selective Permeability

Answer 34

- Non-polar molecules are hydrophobic and can easily cross the lipid bilayer of the membrane - Polar molecules are hydrophilic and have difficulty passing through the hydrophobic core of the membrane - Charged molecules have a sphere of water molecules around them that prevents their passage through the membrane - Large molecules don't fit

Question 35

Selective Permeability - Transport Proteins

Answer 35

- Channel: Hydrophilic channel that allows for polar and charged molecules to pass through - Carrier: Holds onto certain molecules and changes shape to shuttle molecule across membrane

Question 36

Passive Transport

Answer 36

Diffusion of a substance across a membrane with no energy investment; No energy since it moves down the concentration gradient because it represents potential energy

Question 37

Diffusion

Answer 37

- Occurs across a cell membrane if there is a concentration gradient - Each type of molecule diffuses along its own concentration gradient, independently of other molecules - Only small, hydrophobic, uncharged solute molecules are able to diffuse through the phospholipid bilayer

Question 38

Osmosis

Answer 38

- The diffusion of water across a selectively permeable membrane - Occurs when a concentration gradient exists for solute molecules that cannot diffuse - Water diffuses to balance the concentration - Membranes have channel proteins called aquaporins that allow movement of water

Question 39

Hypotonic

Answer 39

- Solute concentration of the solution is less than that of the cell - Water enters the cell - Animal cells swell and lyse - In plant cells, uptake of water creates turgor pressure that pushes out on the cell wall and keeps the plane cells firm

Question 40

Isotonic

Answer 40

- Solute concentration of the solution is the same as that of the cell - No net movement of water - Animal cells do best in isotonic environments - Plant cells become limp because there is no turgor pressure

Question 41

Hypertonic

Answer 41

- Solute concentration of the solution is more than that of the cell - Water leaves the cell - Animal cells become shriveled - Plant cells undergo plasmolysis

Question 42

Faciliated Diffusion

Answer 42

- Diffusion of solute particles across the membrane with help of transport proteins - Transport proteins provide hydrophilic passageways that allow small, polar, molecules and ions to cross

Question 43

Active Transport

Answer 43

- Uses energy (ATP) to move solutes against their concentration gradients - Carrier proteins called "protein pumps" are the transport proteins involved

Question 44

Bulk Transport

Answer 44

- Transportation of large molecules - Large molecules must be packaged in vacuoles or vesicles in order to be transported across the membrane - Requires ATP

Question 45

Endocytosis

Answer 45

- The cell takes in material by forming new vacuoles/vesicles from the plasma membrane - Plasma membrane sinks inward to form a picket. The picket deepens and pinches in, forming a vacuole/vesicle

Question 46

Exocytosis

Answer 46

- The cell exports material by fusing vesicles with the plasma membrane - A transport vesicle fuses with the plasma membrane and releasing the contents outside