Cell Communication and Cell Signals (U6)

Question 1

Plant intercellular junctions

Answer 1

plasmodesmata - channels that allow cytosol to pass between cells

Question 2

Animal intercellular junctions

Answer 2

tight junctions - membranes of adjacent cells fused
desmosomes - anchoring junctions
gap junctions - allow cytoplasmic movement between adjacent cells

Question 3

Signal transduction pathway

Answer 3

convert signals into cellular responses

Question 4

Ligand

Answer 4

a signal molecule the binds with the cell receptor

Question 5

Autocrine signal

Answer 5

affects the same cell

Question 6

Paracrine signal

Answer 6

affects nearby cells

Question 7

Endocrine (hormonal) signal

Answer 7

affects distant cells

Question 8

Steps of cell signaling

Answer 8

reception, transduction, and response

Question 9

Ion-gated channels

Answer 9

a signal molecule binds to a protein and the pore opens as ions go in

Question 10

Protein Kinase receptors

Answer 10

a signal molecule attaches to the receptor and which causes an enzymatic reaction

Question 11

G-protein receptors

Answer 11

GTP is attached to receptors, binding with protein receptor activates G-protein

Question 12

Amplification

Answer 12

cascade multiplier that creates a fast response

Question 13

Negative feedback

Answer 13

maintains homeostasis to raise or lower a specific body condition

Question 14

Lipid-based horomones

Answer 14

hydrophobic, diffuse across cell membrane and turn on genes

Question 15

Lipid-based hormones

Answer 15

hydrophobic, diffuse across cell membrane and turn on genes

Question 16

Protein-based hormones

Answer 16

hydrophilic, can’t diffuse across cell membrane, trigger secondary messenger pathway

Question 17

Pathogens

Answer 17

foreign antigens, ex. bacteria, virus, fungi, worms, toxins

Question 18

Innate immunity

Answer 18

non-specfic immunity you are born with

Question 19

Adaptive immunity

Answer 19

immunity acquired by contact with pathogens, relies on memory

Question 20

First line of defense

Answer 20

non-specific barriers, skin and mucous membranes

Question 21

Second line of defense

Answer 21

non-specific internal barriers, such as leukocytes

Question 22

Inflammatory response

Answer 22

increase in body temp slows down invaders and increases WBC defense

Question 23

Third line of defense

Answer 23

acquired defense that fights based on an invaders antigen

Question 24

Antigen

Answer 24

cellular name tag protein

Question 25

Antibody

Answer 25

protein tha binds to a specific antigen

Question 26

Resting potential

Answer 26

when a neuron is unstimulated, -70mV

Question 27

How does a neuron reset itself?

Answer 27

by using the sodium-potassium pump

Question 28

How are signals received?

Answer 28

transported via vesicles and release through ion-gated channels in synapse

Question 29

Why do cells divide?

Answer 29

for reproduction, growth, and repair

Question 30

Phases of the cell cycle

Answer 30

interphase, prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis

Question 31

Interphase

Answer 31

most of cell cycle life, where DNA synthesis takes place

Question 32

Prophase

Answer 32

chromatin condenses, nucleus disappears, spindle and centrioles are formed

Question 33

Prometaphase

Answer 33

spindle fibers attach to centromeres, chromosomes begin moving

Question 34

Metaphase

Answer 34

chromosomes align along the middle of the cell

Question 35

Anaphase

Answer 35

sister chromatids separate at the kinetochores and are pulled to opposite poles

Question 36

Telophase

Answer 36

daughter nuclei form and chromosomes disperse

Question 37

Cytokinesis in animals

Answer 37

actin filaments form a cleavage furrow and separates cell

Question 38

Cytokinesis in plants

Answer 38

cell plate forms and new cell wall is laid down between membranes

Question 39

Binary fission

Answer 39

single circular chromosomes and no membrane bound organelles believed to be beginning of mitosis

Question 40

Cyclin and Cdk

Answer 40

protein signals that promote cell growth and division

Question 41

Irreversible cell cycle checkpoints

Answer 41

replication of genetic material and separation of sister chromatids