Cacti
What can be said about the leaves of cacti?
They are leafless
What is the shoot apical meristem protected by?
Leaf primordia
What can be said about the orientation of phloem and xylem in leaves?
How long have prokaryotes been around?
3.5 billion years
How are cacti shaped? How does help benefit them?
Cacti are columnar-shaped. This allows for an avoidance of direct sunlight that would cause water loss.
Where is the phloem located in relation to the xylem when looking at a cross section of a stem?
The phloem is located on the outside with the xylem being more central.
What controls the size of the stoma?
Guard cells
What are the differences between the chromosomes of prokaryotes and eukaryotes?
Chromosomes of prokaryotes are single and circular. Chromosomes of eukaryotes are numerous; there's not just one kind
What is the purpose of accordion folds of cacti?
It allows for the stem to expand, causing greater surface area, when water is plentiful.
What are all of the functions of a stem?
Photosynthesis, leaf production, support, transport food, transport water, protection, leaf elevation
Why does a cuticle cover leaves?
It prevents desiccation
How much of the world's biomass are prokaryotic organisms responsible for?
90%
Is the surface area or volume of a cactus greater? Why is this beneficial to the cactus?
The volume is greater than the surface area. This is beneficial because a smaller surface area means less water loss.
Are the following present in a stem?
Nodes
Cuticle
Endodermis
Nodes- yes
Cuticle- yes
Endodermis- no
What is thicker- the cuticle on the upper epidermis or the lower epidermis? Why?
The cuticle of the upper epidermis is thicker because it is exposed to the Sun, which would mean more water loss and there aren't stoma to control ventilation.
Does compartmentalization exist in prokaryotic organisms?
No, it does not. There are no structured organelles that exist for specific functions. It is not necessary because the organisms are so simple.
What is biomimicry? How have cacti been used as an example of this?
Biomimicry is basing new technology off of things found in nature to solve problems. Cacti have been used as an inspiration for architecture. Buildings are created to look like cacti, allowing for minimal energy usage and water conservation in hot regions.
Is structural support important in stems? Why or why not?
Structural support is important because stems are exposed to the environment, weather, and predators. It needs structure to cope with these things.
What are the differences between the palisade mesophyll and the spongy mesophyll? How does this correlate with their functions?
The palisade mesophyll is densely packed with chlorophyll and columnar-shaped. This allows a good location for photosynthesis to occur. The spongy mesophyll is loosely packed and has few chloroplasts. This allows a good location for internal gas exchange to occur.
Name all cell contents that could be present in a prokaryotic organism.
cell wall, ribosomes, DNA, plasma membrane, thylakoid in photosynthetic bacteria, flagella