Exam 2 Flashcards
Modules 6 & 7
What are the first parts of the plant to emerge from a seed?
the radicle and plumule
What roles do roots play for plants?
-absorb water and nutrients
-anchorage
*additional function in some plants –> act as a storage organ for carbohydrates and starches
How are minerals and water absorbed by roots?
dissolved mineral nutrients and water required for growth are absorbed by the root hairs, which are extensions of the epidermal cells
Where is the zone of maturation on the root apical meristem?
top where the root hairs are; location where cells are mature
Where is the zone of elongation on the root apical meristem?
underneath the zone of maturation; where cells grow in length
Where is the zone of division on the root apical meristem?
above the root cap; where cells are actively dividing (undifferentiated)
Where is the root cap on the root apical meristem?
the tip of the root; where newly developed cells are protected from being damaged from soil debris
Root system facts
*the root system is about one-quarter to one-third of the total of the entire dry weight of any plant
*the tap root usually grows downward and the branch roots grow downward or horizontally
What does the root hair do?
absorb water and nutrients
What does the epidermis do for the root?
protects the root
Root: Endodermis and Casparian Strip
act as a waterproofing layer & prevents water from escaping
Root: Xylem
moves water & nutrients
Root: Phloem
moves food (carbohydrates)
Root: Cortex
parenchyma cells for storage of water, gases and carbohydrates
What are adventitious roots and why are the important to AG?
*roots that are not where roots should normally be
*used to propagate plants in Ag
What are the functions of stems?
support plants to capture sunlight
Stem: epidermis
protects the stem from desiccation (drying out)
Stem: Collenchyma
provides structure that can still bend
Stem: Parenchyma
storage of water, carbohydrates, gases, some photosynthesis
Stem: Primary Phloem
transports carbohydrates
Stem: Primary Xylem
transports water and nutrients
Stem: Procambium
producing new xylem and phloem
Stem: Pith Parenchyma
storage of carbohydrates and water
Stem: Cortex
storage of gases and water
What are spurs?
very short stems that remain on plants for many years & contain several buds (often flower buds)
What are rhizomes?
specialized stems that grow underground for asexual reproduction
What are stolons?
stems that grow above ground (along the surface) for asexual reproduction
What are corms?
underground stems modified for carbohydrate storage
What are bulbs?
underground stems surrounded by fleshy leaves modified for carbohydrate storage
What are the functions of leaves?
-photosynthesis
-respiration–>conversion of carbs to ATP
-gas exchange
-pull up water from roots
Leaf: Palisade Layer
where more5 photosynthesis is taking place
Leaf: vascular bundles
xylem and phloem, to move CO2, water & nutrients
Leaf: Spongy Mesophyll Parenchyma
storage, allow for water & gas exchange
Leaf: Epidermis
protects the leaf tissue
Leaf: Stomates
passages that allow for gas & water vapor exchange
Leaf: Guard Cells
open & close stomate passage
Where is the xylem and phloem in woody tissue?
-rings of woody tissue are Xylem; all dead tissue
-the thin strip below the bark is Phloem tissue; all living tissue
What happens to a plant if you disrupt the phloem?
Girdling: it can kill a tree or it is used to increase the sugar of early season fruit trees
What are protoxylem and protophloem?
-newly developed xylem and phloem
-originally created in the vascular cambium
Primary Xylem and Primary Phloem
Primary Xylem grows inward and Primary Phloem grows outward; bard grows both inward and outward
What forms the rings in woody tissue?
-growth during fall & winter is slow, creating small pores (tracheids) and dark tissue
-growth during spring & summer is fast, resulting in larger and lighter colored pores (tracheids)
What is the main component of xylem tissue in gymnosperms? How does this influence what we use these trees for? (soft woods)
-tracheids are the main component of xylem tissue in gymnosperms
-use this when we need materials that are lighter/cheaper
-frames, building
What is the main component of xylem tissue in angiosperm trees? How does this influence what we use these trees for? (hard woods)
-vessel elements are the main components of xylem tissue in angiosperms
-grows slowly, harder to work with, stronger
-furniture would be an example
What is the cork cambium?
-creates new bark
-it growth both outward & inward from the cork cambium
What are lenticels? What are they used for?
-pores/openings in the bark
-they are used for gas exchange in wood tissue
What are the two types of plants?
Non-Vascular and Vascular
Non-vascular
-no xylem or phloem
-ex: mosses, liverworts, algae, lichen
Vascular
-xylem and phloem
-Spore reduction
-gymnosperms “naked seeds”
-angiosperms (flowering plants)
Spore Reduction examples
ferns, horsetails, club “mosses”
Gymnosperm examples
pine trees, cycads, cedar trees, fir trees, ginkgo trees
Angiosperms
-monocots or dicots
monocots: grasses & bulbs
dicots: all other flowering plants, fruit/nut trees, vegetable crops, roses/lilacs etc.
How do non-vascular plants move water, nutrients and carbohydrates throughout plants?
they can only move water, nutrients and carbohydrates by osmosis
Plant vascular system
xylem and phloem
5 Monocot attributes
- one cotyledon/seed leaf
- veins are parallel
- roots are fibrous
- vascular bundles are scattered throughout the stem
- flower parts (petals & filaments) are in multiples of 3
5 Dicot attributes
- two cotyledon/seed leaf
- veins netlike/complex
- taproot
- vascular bundles are in a ring around the edge
- flower part (petals & filaments) are in multiples of 4
What types of buds are there?
-vegetative: develop into a shoot
-flower: which open to produce a flower or flowers
-mixed buds: open to produce both shoots and flowers
What are latent buds?
some buds remain latent for long periods of time and become embedded in enlarging stem tissue
What are adventitious buds?
buds that grow in a place where buds are not normally growing
How do flower buds form?
-form by the differentiation of vegetative buds into flower parts
-in angiosperms, specialized floral leaves on the stem are adapted for sexual reproduction–these are the flowers
What is inflorescence?
scientific term for a flower-shape/form helps determine the species, genus, and family
Female Parts of a flower
stigma + style + ovary
Male Parts of a flower
anther+ filament = stamen
Ovarian positions of a flower
-Superior: above the sepal
-Half inferior: in between ovaries and sepal
-inferior: above ovaries
What are complete flowers?
have a pistil, stamen, petals & sepals
What are incomplete flowers?
missing one or more of the 4 main parts
What are perfect flowers? (most common)
-have both the pistil and stamen
-ex: peaches, beans, almonds, cotton
What are imperfect flowers?
lacking pistil or stamen
What is a dioecious plant?
-male flowers + female flowers on different plants
ex: kiwi and pistachios
What is a monoecious plant?
-male flowers + female flowers on the same plant
ex: corn, walnut, pecans
What is pollination?
when pollen lands on a receptive stigma
Describe self-pollination
the pollen from its own flower lands on its own stigma
Describe cross pollination
pollen from one pollen of a plant lands on another receptive stigma of a plant
What are the different ways cross-pollination may occur?
-insects like bees
-birds, bats
-wind
-water
What is a fruit?
seed or seeds with associated ovary wall
What is a carpel? What is a pericarp?
-a carpel is a section of an ovary
-a pericarp is a covering for a carpel
What are simple fruits?
they have a single ovary formed from one flower
Fleshy simple fruits
the entire pericarp and accessory parts develop into succulent tissue
Semi-fleshy simple fruits
inbetween dry and fleshy
Dry simple fruits
outer parts of fruit which is dry
Berry
A pulpy fruit from one or more carpels that develops few too many seed (bananas, peppers, papayas, grapes, tomatoes); simple, fleshy fruit
Pepo
formed from an inferior ovary that develops from multiple carpels each baring many seeds (cucumbers, melon, squash and watermelon); simple, fleshy fruit
Drupe
simple fruit derived from single carpel
-exocarp: the outer layer becomes the thick skin
-mesocarp: the middle layer becomes thick and fleshy
-endocarp: the inner layer becomes hard and stony (peaches, plums, cherries); simple, fleshy fruit
Pome
a simple fruit made up of several carpels (apples, pears, and quince’s); simple, fleshy fruit
Legume or Pod
they have a single carpel which usually dehisces along both carpel sutures (peas, beans); semi-fleshy or dry simple fruits
Schizocarp
fruit formed from two or more carpels that at maturity yield two one-seeded halves (carrots, dill, cilantro); semi-fleshy or dry simple fruits
What is an aggregate fruit?
-have many ovaries on a single flower
ex: strawberries, blackberries
What are multiple fruits?
there are individual ovaries fused into a single structure born or on a common stalk
