Plant cell biology

Question 1

How do animals acquire their multicellular state?

Answer 1

from cell division and sticking together and failing to separate

Question 2

Name the 3 difference between a plant cell to an animal cell?

Answer 2

• contains a vacuole
• contains chloroplasts
• the cell wall sits outside the cell membrane

Question 3

difference in Golgi bodies between plants and animals?

Answer 3

1 Golgi is found in animal cell whereas lots of Golgi bodies are found in a plant cell

Question 4

Name the main 2 roles of the cell wall?

Answer 4

structure and protective layer

Question 5

What forms the shape of plant cells?

Answer 5

water in the vacoule

Question 6

Name the 4 main components that make up the cell wall

Answer 6

water
cellulose microfibrils
hemicelluloses
pectin

Question 7

what other 2 components modify teh cell wall architecture?

Answer 7

glycoproteins and enzymes

Question 8

What are the 3 main functions of hemicelluloses?

Answer 8

• act as a linker between cellulose microfibrils
• form hydrogen bonds with microfibrils
• limit the extensibility of teh cell wall

Question 9

Name the 2 locations where pectin can be found?

Answer 9

primary cell wall and middle lamella

Question 10

What are the 2 functions of pectin?

Answer 10

• soack up water

- gives wall flexibility and resits compression

Question 11

How much percentage of cell walls is water?

Answer 11

65%

Question 12

Where is cellulose synthesised?

Answer 12

Plasma membrane

Question 13

How does the cell remain its shape?

Answer 13

• the cell wall
• protoplast
• round shape due to turgor pressure

Question 14

How is the cell wall remodelled during growth?

Answer 14

• bonds between cellulose fibrils loosened
• more water enter the vacuole
• crosslinks cleared + rebuilt by enzymes
• expansins disrupt H+ bonds between cellulose and hemicellulose

Question 15

What is cell expansin hugely important in?

Answer 15

plant development

Question 16

What is the 2 main roles of secondary cell walls?

Answer 16

structure

evolution of large plants

Question 17

why don’t plant cell shave intermediate filaments?

Answer 17

they have a cell wall instead to provide a strong framework

Question 18

What are microtubules?

Answer 18

big structures made up of tubulin units which assemble together into big hollow filaments

Question 19

What is actin filament?

Answer 19

actin molecules polymerised together which regulates polymerisation

Question 20

How do microtubules and cellulose synthases work together?

Answer 20

1. cellulose synthases rub along microtubule tracks

2. microtubule motors may propel the cellulose synthases along

Question 21

Where is plasmodesmata found?

Answer 21

• in pit fields
• found in clusters
• in areas with least turgor pressure

Question 22

What is the purpose of the space in the plasmodesmata?

Answer 22

It enables molecules to move through the plasmodesma through the endoplasmic reticulum or through the cytoplasmic route

Question 23

How do plasmodesmata allow plant communication?

Answer 23

= small molecules pass through the cytoplasmic sleeve

= substances move through the symplast between cells without ever having to go effectively outside

Question 24

What molecules can pass through the plasmodesma?

Answer 24

smaller molecules like nutrients and growth regulators

Question 25

What proteins can’ pass through the plasmodesma?

Answer 25

-larger molecules like proteins and mrna

Question 26

Name 3 things that regulate the size of plasmodesmata

Answer 26

• plant viruses
• plant developmental state of cells
• environmental and physiological signals

Question 27

What does it mean that guard cells are simplistically isolated?

Answer 27

• they are not connected to the plasmodesmata

Question 28

Why are guard cells simplistically isolated>

Answer 28

to maintain turgor pressure so solutes can’t ge in

Question 29

Name teh hormone that controls growth

Answer 29

Gibberellin (GA)

Question 30

What is the phragmoplast?

Answer 30

a plant cell specific structure that forms during late cytokinesis

Question 31

Where does cell division take place in plants?

Answer 31

in specialised areas called meristems

Question 32

How is phragmoplast size and position regulated?

Answer 32

kinesin and overlapping microtubules

Question 33

How do microtubules govern the direction of cell expansion?

Answer 33

by affecting cell wall biosynthesis

Question 34

How do microtubules govern the orientation of cell expansion?

Answer 34

regulated by environmental and developmental signals

Question 35

What is the main driver of growth in tip growing cells?

Answer 35

actin