Lecture 1: In The Beginning

Question 1

what does AU stand for?

Answer 1

astronomical unit

Question 2

what is regolith?

Answer 2

martian/lunar soil

Question 3

what is the anthropocene period?

Answer 3

current time period starting around the industrial revolution

Question 4

what is an apoplast?

Answer 4

all the cell walls in a plant

Question 5

what is the fragmoplast?

Answer 5

a structure found in plant cells that helps separate daughter cells during cytokinesis

Question 6

why does Mars have no magnetosphere?

Answer 6

the mantle is dormant meaning no friction is created by the liquid moving

Question 7

did mars used to have a magnetosphere and how do we know?

Answer 7

volcanoes present

Question 8

what does a low atmospheric pressure indicate?

Answer 8

high speed storms are inaffective on Mars

Question 9

what percent of the earth’s surface is covered by water?

Answer 9

70%

Question 10

why doesn’t mars have any surface water?

Answer 10

atmospheric pressure is less than water pressure

Question 11

what ‘water’ does Mars have?

Answer 11

ice and a sub surface lake close to the South pole

Question 12

what evidence is there that Mars used to have flowing surface water?

Answer 12

rock erosion

Question 13

what is soil?

Answer 13

a sum product of mineral weathering and organic decay

Question 14

what does the moon produce?

Answer 14

tides known as regular and predictable changes in localized, interface chemistries that alternate between 2 different states

Question 15

how many gigatones of biomass is on earth?

Answer 15

450 Gt C

Question 16

where are 99% of plants found?

Answer 16

terrestrial land

Question 17

what did chemotrophs produce and what were the consequences?

Answer 17

H was reduced from the atmosphere

Question 18

what are stromatolites?

Answer 18

photosynthetic organisms (such as cyanobacteria) that removed CO2 from the atmosphere leading to a global freeze 3.5BYA

Question 19

what happens to oxygen if there is lots of photosynthesis?

Answer 19

LOTS of oxygen waste is produced leading to anaerobic bacteria dying, O2 dissolving Fe ions to create iron ore and the Great Oxidation Event (GOE) that formed the ozone layer (1-2BYA)

Question 20

what features of a plant cell are only found in plant cells?

Answer 20

plasmodesmata, chloroplasta, and a vacuole (with tonoplast)

Question 21

what is the cell wall?

Answer 21

a solid but dynamic and metabolically active organelle made of largely cellulose and other polysaccharides (pectins/hemicellulose)

Question 22

what is cellulose?

Answer 22

the most abundant polymer of glucose linked by B1-4 bonds that is made into fibres by enzyme complexes (rosettes) that are guided by the microtubule exoskeleton

Question 23

what occurs to the cell wall during cytokinesis?

Answer 23

a new cell wall is generated perpendicular to the mitotic spindle in the fragmoplast

Question 24

what controls the loosening of the cell wall?

Answer 24

proteins and enzymes such as expansins and pectinases

Question 25

what are plasmodesmata?

Answer 25

holes through the plasma membrane ER and cytosol of one cell connected to it's neighbour

Question 26

what is the symplast?

Answer 26

the continuous cytoplasm that the entire plant is composed of (except for the stomatal guard cells

Question 27

what are the 2 types of modified chloroplast?

Answer 27

etioplast: immature (pale yellow/colourless) Amyloplasts: specialised for storafe of starch in tubers and seeds or gravity sensing in pulvini and the root cap columella

Question 28

what percent of the cell does the vacuole occupy?

Answer 28

90%

Question 29

what are the 3 functions of the vacuole?

Answer 29

1. maintains positive hydrostatic pressure via osmotic influxes 2. maintains pH and ionic homeostasis in cytoplasm 3. repository for chemicals, solutes, and enzymes

Question 30

what is the membrane of the vacuole called?

Answer 30

Tonoplast