Brooks Biodiversity Unit 3 Exam Questions and
Correct Answers 2024 with complete solution.
Plants Architecture
Plant needs
i. collection & conversion of solar energy -> leaves
ii. positioning & support of leaves -> stems
iii. anchorage & absorption -> roots
iv. transport -> vascular system
Leaf Structure
Epidermis, Mesophyll, and Vein (Vascular Bundle)
Epidermis contains what?
- Cuticle
- Guard cells with Stomata
Epidermis
outermost cell layer of a plant body
cutin: (wax) excreted by epidermis
Cuticle
Waxy waterproof covering of a plant.
Produced by the epidermis and has wax to resist desiccation.
Guard Cells
Responsible for opening and closing stomata.
Works together with stomata to regulate gas exchange.
Prevents movement of water ACROSS surface
Stomata
Small openings on the underside of a leaf through which oxygen and carbon dioxide
can move.
Mostly on lower surfaces, sometimes on upper surfaces. Found on both surfaces.
Allows for gas exchange.
2 aspects of Photosynthesis
light dependent reactions
light independent reactions
Mesophyll contains what?
- Parenchyma
- Dicots have Palisade & Spongy Layers
Mesophyll
Middle leaf structures photosynthetic layer.
Parenchyma
Ground tissue that forms the bulk of the mesophyll
Can be modified into collenchyma and sclerenchyma
Thin and flexible cells
Most common and versatile ground tissue
Used for metabolic functions and storage of organic products
Palisade & Spongy layers
,Palisade layer: where light dependent reactions occur, near the surface. Top part of the
mesophyll in dicot plants.
Spongy mesophyll or spongy parenchyma: soft lower layer. Has access to CO2 through
stomata. Kelvin Cycle: where carbon fixation occurs, converting nonorganic CO2 into
sugars.
Vein (Vascular bundle)
Transports materials throughout the leaf and contains the xylem and phloem.
Separating the VB = damage.
Stem Structure
Epidermis, Cortex, Collenchyma, Sclerenchyma, Vascular Tissues
Xylem
(Xylem Up)
Distributes water from roots throughout
Aimed towards stem
Red
Tells age of tree
Contains: tracheids & vessel members
Tracheids
Thin, hollow, narrow tube, dead cells with perforated, tapered ends.
Vestigial structure
First kind of tube made
Present in early vascular plants and present in angiosperms and gymnosperms (slow
flow)
Vessel Members
Thick, hollow, wide tube, dead cells with large holes on end.
Clearly visible
Phloem
(Phloem Down)
Distributes the products of photosynthesis (sugary water) to plants tissues.
Blue
Contains: Sieve tube members (element) & Companion cells
Sieve Tube Members
hollow, living cells with perforated cells
Companion Cells
living cells that help keep sieve tube member cells alive.
Production of sugars in Kelvin Cycle require transportation done by companion cells into
phloem
Which 4 cell types is most active metabolically when fully functional?
companion cells
Epidermis in Trees
is replaced by bark or cork. Produced by the cork cambium (tissues that produce other
tissues).
Cork (dead) = phloem (alive)
Cork cambium produces cork.
Trees grow wider cause xylem will get clogged
, The cork is produced when?
Secondary phloem
Composition of Bark
is produced from phloem, cork cambium, or cork.
Lenticels
cracks in the bark to facilitate gas exchange
Secondary Growth
How a plant increases in girth (diameter)
1. Vascular Cambium
2. Cork Cambium
3. Wood
4. Bark
5. Lenticels
6. "Girdling Plants"
Wood
produced by xylem.
annual rings
Heartwood: clogged xylem, little water transport. Located deeper into trunk, harder
wood
Sapwood: newer xylem, free flowing water transport. Phloem makes sap.
Girdling Plants
Weed-Whakers
Cutting a HORIZONTAL band around the circumference of the plant, can be deadly
because the vascular cambium, in which nutrients and water travel vertically, can be
damaged.
What happens to initial phloem?
it gets crushed
What happens to the xylem?
it gets clogged
Cortex
Yellow layer inside epidermis
Separated by a ring of vascular bundles.
Ground Tissue System
Includes various cells specialized for functions such as storage, photosynthesis, and
support
Types of Ground Tissue
Parenchyma, Collenchyma, Sclerenchyma
Collenchyma
celery fibers for support
Sclerenchyma
hard fibers & nodules responsible for support
(ex) rope
Sclerids
nodules glued together to form shells of nuts.
Fibers
secretions that reinforce the stem
Correct Answers 2024 with complete solution.
Plants Architecture
Plant needs
i. collection & conversion of solar energy -> leaves
ii. positioning & support of leaves -> stems
iii. anchorage & absorption -> roots
iv. transport -> vascular system
Leaf Structure
Epidermis, Mesophyll, and Vein (Vascular Bundle)
Epidermis contains what?
- Cuticle
- Guard cells with Stomata
Epidermis
outermost cell layer of a plant body
cutin: (wax) excreted by epidermis
Cuticle
Waxy waterproof covering of a plant.
Produced by the epidermis and has wax to resist desiccation.
Guard Cells
Responsible for opening and closing stomata.
Works together with stomata to regulate gas exchange.
Prevents movement of water ACROSS surface
Stomata
Small openings on the underside of a leaf through which oxygen and carbon dioxide
can move.
Mostly on lower surfaces, sometimes on upper surfaces. Found on both surfaces.
Allows for gas exchange.
2 aspects of Photosynthesis
light dependent reactions
light independent reactions
Mesophyll contains what?
- Parenchyma
- Dicots have Palisade & Spongy Layers
Mesophyll
Middle leaf structures photosynthetic layer.
Parenchyma
Ground tissue that forms the bulk of the mesophyll
Can be modified into collenchyma and sclerenchyma
Thin and flexible cells
Most common and versatile ground tissue
Used for metabolic functions and storage of organic products
Palisade & Spongy layers
,Palisade layer: where light dependent reactions occur, near the surface. Top part of the
mesophyll in dicot plants.
Spongy mesophyll or spongy parenchyma: soft lower layer. Has access to CO2 through
stomata. Kelvin Cycle: where carbon fixation occurs, converting nonorganic CO2 into
sugars.
Vein (Vascular bundle)
Transports materials throughout the leaf and contains the xylem and phloem.
Separating the VB = damage.
Stem Structure
Epidermis, Cortex, Collenchyma, Sclerenchyma, Vascular Tissues
Xylem
(Xylem Up)
Distributes water from roots throughout
Aimed towards stem
Red
Tells age of tree
Contains: tracheids & vessel members
Tracheids
Thin, hollow, narrow tube, dead cells with perforated, tapered ends.
Vestigial structure
First kind of tube made
Present in early vascular plants and present in angiosperms and gymnosperms (slow
flow)
Vessel Members
Thick, hollow, wide tube, dead cells with large holes on end.
Clearly visible
Phloem
(Phloem Down)
Distributes the products of photosynthesis (sugary water) to plants tissues.
Blue
Contains: Sieve tube members (element) & Companion cells
Sieve Tube Members
hollow, living cells with perforated cells
Companion Cells
living cells that help keep sieve tube member cells alive.
Production of sugars in Kelvin Cycle require transportation done by companion cells into
phloem
Which 4 cell types is most active metabolically when fully functional?
companion cells
Epidermis in Trees
is replaced by bark or cork. Produced by the cork cambium (tissues that produce other
tissues).
Cork (dead) = phloem (alive)
Cork cambium produces cork.
Trees grow wider cause xylem will get clogged
, The cork is produced when?
Secondary phloem
Composition of Bark
is produced from phloem, cork cambium, or cork.
Lenticels
cracks in the bark to facilitate gas exchange
Secondary Growth
How a plant increases in girth (diameter)
1. Vascular Cambium
2. Cork Cambium
3. Wood
4. Bark
5. Lenticels
6. "Girdling Plants"
Wood
produced by xylem.
annual rings
Heartwood: clogged xylem, little water transport. Located deeper into trunk, harder
wood
Sapwood: newer xylem, free flowing water transport. Phloem makes sap.
Girdling Plants
Weed-Whakers
Cutting a HORIZONTAL band around the circumference of the plant, can be deadly
because the vascular cambium, in which nutrients and water travel vertically, can be
damaged.
What happens to initial phloem?
it gets crushed
What happens to the xylem?
it gets clogged
Cortex
Yellow layer inside epidermis
Separated by a ring of vascular bundles.
Ground Tissue System
Includes various cells specialized for functions such as storage, photosynthesis, and
support
Types of Ground Tissue
Parenchyma, Collenchyma, Sclerenchyma
Collenchyma
celery fibers for support
Sclerenchyma
hard fibers & nodules responsible for support
(ex) rope
Sclerids
nodules glued together to form shells of nuts.
Fibers
secretions that reinforce the stem
