Biology Plant Test - Questions
Angiosperm Development
1: Pre-Teen Plant 2: Flower Development 3: Pollination 4: Fertilization 5: Germination, Fruit development 6: Seed Dormancy 7: Seed Development 8: Seed Dispersal
How many bands of xylem does a three-year-old tree stem have?
3
When does secondary growth in trees occur?
After a dormant season, and during spring when there is more sunlight available
What do plants need for photosynthesis?
Carbon dioxide
If you wanted plants to come up each year in your garden, what kind of plant would you plant?
I would plant a perennial plant (tree, sage, grass)
A thin, waxy layer is present along the outside of a tree's cork. Explain how this layer helps cork function.
It is a hydrophobic (repellent of water) layer, so it protects the tree from water loss
What kinds of environmental factors during the year might influence growth?
Temperature, sunlight, precipitation
What do plants need nitrogen for?
To make DNA/RNA and proteins
What is the difference between apical meristem and lateral meristem and what kind of growth do each cause?
apical meristems are meristems located at the apical buds at root/shoot tips and they cause primary growth. lateral meristems are meristems that cause secondary growth thanks to the vascular and cork cambiums
What makes something a plant?
autotrophs, multicellular, producers, eukaryotic
Why is it not good to pull off tree bark?
because it exposes the tree's cambium layers, which weakens the tree's injury response and can stop food from flowing to that part of the tree--ultimately causing that part of the tree to dry and decay
Flowers that are pollinated by the wind have smaller petals and sepals than flowers that are pollinated by insects or animals. Why are small petals and sepals and advantage to these flowers?
because it increases their chances of wind pollination, and thus do not need to attract pollinators (because of aerodynamics)
Why can't soil absorb all water poured on it?
because soil is negatively charged and water is polar (negative and positive end) so there is only so much water soil can absorb
How can a tree's age be determined?
count the number of rings
How do tree rings form?
each year the division of the vascular and cork cambium causes new tree rings to form, the sizes of the cells produced during the season (as a result of moisture and climate) causes the tree rings to be wider or thinner
Where in a root would you look for cells in metaphase?
in the root tips
If you pound a nail into a young tree (don't do it!) and go back to the tree when it is fully grown, where would you look for the nail?
in the same spot it was originally placed it because a tree trunk only grows in circumference
Where is the oldest Xylem found in a cross-section of a tree?
it is found in the center of the tree because the vascular cambium next to it produces new xylem each year which pushes the preliminary xylem to the center-most section of the tree
What specific cells are found in the Xylem and Phloem?
phloem = sieve tubes xylem = tracheids and vessel elements
Where would I find primary vs secondary growth?
primary growth = root/shoot tips (ex apical/terminal buds) secondary growth = vascular/cork cambiums
Explain why a heavy rainfall on a fruit orchard in the spring might result in a poor fruit yield in the fall.
since flowers develop in the spring, and fruit comes from the pollen of flowers being fertilized, if there is heavy rainfall in the spring, that could knock the new flowers off of the tree, and wash the pollen away, causing a poor fruit yield
For what biological reasons do farmers object to people picking apple blossoms during apple blossom season?
since fruit comes from flowers (if pollen transfers and fertilization occurs), if people pick apple blossoms, there will be no apples
Why does a flower have more pollen grains (sperm) than ovules?
since pollen moves, it increases the chances of fertilization
How is the structure of root cortex cells adapted to their function?
since their function is the storage of materials, they are large thin walled cells
Why do flowers that are pollinated by insects have large, brightly colored petals?
so that they can attract pollinators (by their color, smell, design, etc) so that they pollinate
Why do you suppose the cell diameter of spring and summer xylem differ?
spring brings on more water so water causes the cells to be larger
What is the innermost layer of the cortex?
the endodermis
What are the functions of the epidermis and endodermis?
the epidermis is the protective skin of a plant and the endodermis is the protective barrier of the vascular cylinder (containing the vascular tissue)
Name the main cells that make up the central cylinder/vascular cylinder/steel of a root.
the xylem and phloem
How is the shape and function of the central cylinder of a root similar to a water pipe or blood vessel?
the xylem and phloem cells are like tubes, long conduits from one location to another, passageways to more fluid
What does each cell type transfer (xylem and phloem)?
the xylem transports water and the phloem transports sugar
How is the structure of thick bast fibers adapted for their function?
their function is to support the plant, hence why they are thick walled and don't have a hollow inside
What type of plant cells are "dead at functional maturity?"
tracheids and vessel elements
Does a new band of xylem form in a tree stem during each year of growth?
yes
Are these cell layers (endodermis and epidermis) properly named, based upon their location and function in roots? Explain.
yes, because endo means inside and epi means outside, and those are where there jobs are