Lab Girl Flashcards
… are used to determine the chemical formula of mineral powder, the spacing and intensity allows us to reconstruct the shape
x-rays
Trees grow by…
producing one new sheath after another (tree rings)
- a thicker ring means that more growth occurred during that year
- if a ring is thicker on one side, it is likely that a branch fell off and the tree is evening out the weight of the crown
When it becomes very dry, a cactus…
sheds its roots to prevent the parched soil from sucking all the water back out of it
Resurrection plants (Selaginella lepidophylla) curl up when it gets dry and their leaves fill with sucrose, why is this?
it helps to stabilize and preserve the leaf
During peak growth plants … more
‘sweat’ more (high rates of evapotranspiration)
- more photosynthesis is taking place
- When most of the new leaves have regrown on a tree after the winter less water evaporates from their stomata
Alaska previously belonged to …
Russia but was bought by the US for 2¢per acre
VOCs (volatile organic compounds)
airborne chemicals released by trees (and other sources)
When a tree is attacked by caterpillars it …
signals the attack to other trees using VOCs so that they can produce caterpillar poison before they are attacked
Plants produce … when they are wounded
jasmonic acid
Most plants don’t cope well with frost because…
the water inside the plant cells freezes and expands until the cell wall bursts
Animal cells are more tolerant to freezing because…
their cells produce energy by burning sugars (plants produce their own sugar using sunlight, but there usually isn’t a lot of sunlight during the cold season)
In order to freeze a liquid must have a…
nucleation spot
(a chemical aberration from which the crustal pattern can start to build, if water wouldn’t have such a site it could be cooled to cooled to -40°C and still be in its liquid phase)
A nucleation spot
a chemical aberration from which the crustal pattern can start to build, if water wouldn’t have such a site it could be cooled to cooled to -40°C and still be in its liquid phase
How do conifers and deciduous trees prepare for winter
- cells become more permeable and water flows out
- the sugars, proteins, and acids that are left behind act as an anti-freeze which has a syrup-like consistency and will remain a fluid even below freezing temperatures
- trees do not undergo this process of change when the temperature changes, but when the days begin to shorten (photoperiod)
Most fossilized trees have undergone a process where they were petrified…
by fluids that passed through them and exchanged molecules for minerals slowly turning the tree into a rock