BIO 152 FINAL EXAM 2024 ACTUAL EXAM
COMPLETE ACCURATE 260 EXAM QUESTIONS
WITH DETAILED VERIFIED ANSWERS (100%
CORRECT ANSWERS) /ALREADY GRADED A+
How is sink strength (how many sugars are moving out of the phloem into the
sink cell) determined? - ANSWER..Determined by the speed in which those
sugars are used. The faster they are used, the greater the strength.
What happens as solute potential drops and the sugars move out of the phloem? -
ANSWER..As solute concentration drops and the sugars move out of the phloem,
the water potential within the phloem increases in relation to the xylem, so water
moves into the xylem. This all just follows the water potential gradient.
The actual flow requires no energy input from the plant? - ANSWER..Both (the
actual flow is just following a pressure gradient)
The pressures inducing flow are negative? - ANSWER..Xylem (the pressure
potential in the phloem is positive)
The conducting cells are alive, but with highly modified cytoplasms? -
ANSWER..Phloem
The conducting cells are elongated relative to regular plant cells? -
ANSWER..Both
The fluid moves by mass flow because of a gradient in pressure? -
ANSWER..Both
Thick Roots - ANSWER..Anchor the plant, store carbohydrates and nutrients,
transport water and nutrients from thin roots to stem and leaves
Thin Roots - ANSWER..Absorb minerals and water
,Root hairs - ANSWER..Grow on fine roots, where the vast majority of nutrients,
minerals, and water are taken up, hugely increase root surface area, super tiny so
they can probe into the soil very effectively
Elements that plants need - ANSWER..45% oxygen, 45% carbon, 6% hydrogen,
the other 5% are made up of micro- and macronutrients (macronutrients needed
much more up than micronutrients), these are all called essential elements
Essential Elements - ANSWER..Elements that a plant must have in order to
complete its entire life cycle
Nutrient Acquisition - ANSWER..The net movement of nutrients from the soil
into the plant: water follows the same path because it is following a water
potential gradient
What are the names of the possible pathways? - ANSWER..Within root, two
possible pathways that nutrients and water can move - apoplastic (within the non-
cytoplasm) and symplastic (within the cytoplasm)
What parts does water flow through? - ANSWER..Root hair, epidermis, cortex.
endodermis, stele (vascular cylinder)
Endodermis - ANSWER..A brick wall: it is a brick wall because of a waxy layer
called the casparian strip
Caspian Strip - ANSWER..A layer of wax around every cell in the endodermis:
this means that no water or nutrients can pass apoplastically through the
endodermis, it has to pass through the symplast: this allows the plant to select the
nutrients and everything else that it wants: it can exclude things like pathogens
that it doesn't want
What is the advantage of forcing everything to go through the symplast? -
ANSWER..It allows only things that it wants inside to go through: only things
that have specific transporters can go through
Where is all the stuff that it doesn't let in go? - ANSWER..It is in the cortex
, Liverworts - ANSWER..9,000 species, do not have stomata, only pores
Mosses - ANSWER..15,000 species, have stomata, economically important,
important in florist trade
Hornworts - ANSWER..Only ~100 species, sporophyte long-lived (longer than
in mosses or liverworts)
Types of vascular plants - ANSWER..Lycophytes, Ferns, Gymnosperms,
Angiosperms
Why did plants get taller - ANSWER..Being taller than competitors is important
because they are competing for sunlight
Ferns - ANSWER..Gametophyte and sporophyte phases grow independently
Gymnosperms - ANSWER..Seed producing plants
Angiosperms - ANSWER..Flowering plants
Reason for the development of a vascular system - ANSWER..Plants needed to
be taller than their competitors, but in order to be tall, they needed a way to
transport things like water throughout their bodies. As a solution, they developed
vascular tissue.
What are the common species of byrophytes? - ANSWER..Mosses, Hornworts,
Liverworts
What are the vascular plants? - ANSWER..Angiosperms, Gymnosperms, Ferns,
Lycophytes
Ferns - ANSWER..Gametophyte and sporophyte phases grow independently
4 Divisions of Gymnosperms - ANSWER..Ginkoidae, Cycadidae, Gnetidae,
Pinidae