science: chpt. 7 test

Question 0

In the mid _____ there was a lot of new _______ about cells because of the new ____________.

Answer 0

1800s; theories; microscopes

Question 1

___________ prevents fatty-acid tails from sticking together

Answer 1

Cholesterol

Question 2

What did scientist observe using early microscopes?

Answer 2

Tiny organisms

Question 3

Electron microscopes have about ____ more magnification than compound light microscopes

Answer 3

500x

Question 4

What king of images can be seen with a scanning electron microscopes (SEM)

Answer 4

3D images

Question 5

What is the cell theory?

Answer 5

(1) All living organisms are composed of one or more cells
(2) Cells are the basic unit of structure and organization of all living organisms
(3) Cells arise only from previously existing cells, with cells passing copies of their genetic material on to their daughter cells.

Question 6

What decade did the cell theory become a living thing?

Answer 6

1850

Question 7

Do bacteria cells have nuclei? Why?

Answer 7

No, because they are prokaryotic

Question 8

What is present in eukaryotic cells?

Answer 8

Nucleus

Question 9

Is cholesterol polar or non-polar?

Answer 9

Non polar

Question 10

What substance in the plasma membrane identify chemical signals?

Answer 10

Carbohydrate chain

Question 11

What converts sugars into energy (also called the powerhouse of the cell)?

Answer 11

Mitochondria

Question 12

What organelles are only found in animals?

Answer 12

Lysosome

Question 13

The condition of continuous, random movement of particles but no overall change in concentration of materials

Answer 13

Dynamic Equilibrium

Question 14

Does active transport move substances with or against the concentration gradient?

Answer 14

Against

Question 15

What will happen to a cell in a hypotonic solution solution?

Answer 15

• Plant cells will swell but because of the cell wall it won’t burst.
• Animal cells will swell and possibly burst.

Question 16

What kind of molecules are expelled during exocytosis?

Answer 16

Large molecules

Question 17

Is facilitated diffusion active or passive?

Answer 17

Passive

Question 18

Compare and contrast exocytosis and endocytosis.

Answer 18

Both exocytosis and endocytosis are energy-requiring processes. However, exocytosis expels wastes and secretes substances at the plasma membrane and endocytosis is when large substances from the outside environment enter the cell.

Question 19

Use principles of osmosis to explain wilting.

Answer 19

Osmosis regulates the movement of water across the plasma membrane. This helps maintain homeostasis. If a plant cell is in a hypertonic solution the loss of water causes wilting.