Exam 1 Flashcards
1
Q
What happens in the pressure flow mechanism for phloem transport?
A
Phloem moves sugars from sources to sinks
2
Q
How is sucrose transported in the pressure flow mechanism?
A
Carbohydrates (CHOs) are converted into sucrose at Sources.
Sucrose is actively transported from source cells into sieve tubes or companion cells, then diffused into sieve tubes.
3
Q
What causes the high fluid pressure in sieve tubes at sources?
A
The high solute (low water) concentration in sieve tubes draws water into the tubes by osmosis.
4
Q
What happens to sucrose at the Sinks in the pressure flow mechanism?
A
Sucrose exits phloem at Sinks (e.g., roots, fruits).
5
Q
What happens to water in the pressure flow mechanism?
A
Water follows sucrose and exits the phloem by osmosis.
6
Q
How does transpiration drive water movement in the cohesion-tension mechanism?
A
Transpiration (evaporation of water molecules) occurs through stomata.
This evaporation pulls on the water column, creating tension.
7
Q
What role does cohesion play in the cohesion-tension mechanism?
A
Water molecules in the xylem are attached to each other by hydrogen bonds.
This cohesion allows water to move up the plant in a continuous chain.
8
Q
How is water taken up by the roots in the cohesion-tension mechanism?
A
Water molecules are taken up from the soil by the roots.
As water moves up, it is replaced by water from the soil through osmosis (from high concentration to low concentration).
9
Q
What keeps the water moving from the soil into the roots?
A
As long as transpiration continues, tension draws water from the soil into the roots by osmosis.
10
Q
How do roots use the Casparian Strip to control water and solutes from the soil?
A
In the cortex, water and solutes can move between cells.
When they reach the vascular tissue, they are forced to move across plasma membranes and into cells.
11
Q
What is the role of the Casparian Strip in the endodermis?
A
The Casparian Strip is a waxy barrier in the endodermis.
It forces water and solutes to move across plasma membranes, preventing them from bypassing the cells.
12
Q
How does the Casparian Strip regulate which solutes enter vascular tissue?
A
The Casparian Strip allows plasma membranes to choose which solutes are taken up by the vascular tissue.
It helps allow needed minerals from the soil to pass through and blocks unneeded substances or potential toxins.
13
Q
What is heartwood and its function in trees?
A
Heartwood is dark and older.
It is clogged with resins and other compounds that make it resistant to rotting.
Heartwood no longer moves water.
14
Q
What is sapwood and its function in trees?
A
Sapwood is pale and younger.
It is responsible for moving water through the tree.
15
Q
What is early spring wood?
A
Early spring wood has large diameter xylem cells, which form in the spring.
16
Q
What is late summer wood?
A
Late summer wood has smaller diameter xylem cells, which form in the summer.
17
Q
What are rays in trees?
A
Rays are parenchyma cells that move water and sugars laterally across the tree.
18
Q
What is an annual growth ring in trees?
A
Every year, an annual growth ring is formed with early (spring) and late (summer) wood growth.
19
Q
How is secondary growth produced in woody plants?
A
Vascular cambium cells divide during the growing season.
The cells interior to the cambium become secondary xylem.
The cells exterior to the cambium become secondary phloem.
20
Q
When does secondary growth occur in woody plants?
A
Secondary growth occurs during the growing season.
It stops at the end of the season and resumes next year.
21
Q
How does the secondary xylem and secondary phloem change over time?
A
Secondary xylem accumulates each year.
Secondary phloem does not accumulate like secondary xylem.
22
Q
Where is the vascular cambium located and what does it produce?
A
The vascular cambium is located between the xylem (wood) and phloem (bark).
It produces secondary xylem (wood) and some bark (secondary phloem).
23
Q
Where is the cork cambium located and what does it produce?
A
The cork cambium is located just outside the vascular cambium.
It produces the rest of the bark, including cork.
24
Q
What do wood and bark consist of in terms of secondary growth?
A
Wood consists of secondary xylem.
Bark consists of secondary phloem and cork (produced by cork cambium).
25
What are meristems in plants?
Meristems are tissues where cell division takes place, allowing plants to grow.
26
What is the role of apical meristems?
Apical meristems cause plants to grow in length (primary growth).
They are located at all root tips and shoot tips.
27
What is the role of lateral meristems?
Lateral meristems cause woody stems and roots to get thicker (secondary growth).
28
How do some plants use modified leaves to grow horizontally?
Some plants have modified leaves that grow horizontally, either above or below ground.
29
What is the function of modified leaves that grow underground and are enlarged?
Some plants have modified leaves that grow underground and are enlarged for nutrient storage (e.g., potatoes).
30
What is the role of enormous petioles in some plants?
Some plants have enormous petioles to store water and food.
31
How do modified leaves with thin, coiled tips help some plants?
Some plants have thin, coiled leaf tips that help them climb.
32
Why do some plants have spiny, sharp leaves?
Some plants have spiny and sharp leaves for protection.
33
How do some plants use modified leaves to manage water?
Some plants retain water in their leaves, while others drip it away.
34
What is the ground tissue structure in monocots and eudicots?
In monocots, ground tissue consists of cortex and pith.
In eudicots, ground tissue is divided into cortex and pith (with pith typically inside).
35
What are vascular bundles?
Vascular bundles are groups of xylem and phloem wrapped in a sheath.
They are responsible for transporting water, nutrients, and food throughout the plant.
36
How is vascular tissue arranged in monocot roots?
In monocots, the vascular tissue is arranged in a circle with specs of dermal tissue in the ground tissue.
37
How is vascular tissue arranged in eudicot roots?
In eudicots, the vascular tissue is arranged in an X-shape.
38
How are vascular bundles arranged in monocot stems?
In monocot stems, vascular bundles are scattered throughout the stem.
39
How are vascular bundles arranged in eudicot stems?
In eudicot stems, vascular bundles are arranged in a ring.
40
What is the function and location of the root cap?
Root cap provides protection for the tip of the root.
Located at the bottom of the root.
41
What is the function and location of root hairs?
Root hairs increase the surface area for water absorption.
Water enters root hairs by osmosis.
Located near the epidermis.
42
What is the function and location of the epidermis in roots?
Epidermis provides protection for the root.
Located as the outer layer of the root.
43
What is the function and location of the cortex in roots?
Cortex is responsible for nutrient storage.
Located under the epidermis.
44
What is the function and location of the endodermis in roots?
Endodermis regulates water and solute movement.
Located under the cortex.
45
What is the function and location of the pericycle in roots?
Pericycle is the origination site for lateral roots.
Located under the endodermis.
46
What is the function and location of the vascular tissue in roots?
Vascular tissue (xylem and phloem) is responsible for transporting water, nutrients, and food.
Located at the center of the root.
47
What is the difference between monocot roots and eudicot roots?
Monocot roots have more vascular tissue.
Eudicot roots have more ground tissue.
48
What is the function and location of the root cap?
Root cap provides protection to the tip of the root.
Located at the bottom of the root.
49
What is the function and location of root hairs?
Root hairs increase surface area for water absorption.
Water enters the root hairs by osmosis.
Located near the epidermis of the root.
50
What is the function and location of the epidermis in roots?
The epidermis provides protection for the root.
Located as the outer layer of the root.
51
What is the function and location of the cortex in roots?
The cortex is responsible for nutrient storage.
Located under the epidermis of the root.
52
What is the function and location of the endodermis in roots?
The endodermis regulates water and solute movement.
Located under the cortex of the root.
53
What is the function and location of the pericycle in roots?
The pericycle is the site of origination for lateral roots.
Located under the endodermis of the root.
54
What is the function and location of vascular tissue in roots?
Vascular tissue (xylem and phloem) transports water, nutrients, and food.
Located at the center of the root.
55
What is the difference between monocot roots and eudicot roots?
Monocot roots have more vascular tissue.
Eudicot roots have more ground tissue.
56
What are the characteristics of fibrous roots?
Found in monocots.
Composed of many small diameter roots.
Shallow root system.
57
What are the characteristics of taproots?
Found in eudicots.
Have one large, deep dominant root.
Smaller roots emerge sideways.
58
Why do some species have unusually large taproots?
Taproots are sometimes unusually large to store large amounts of carbohydrates (CHO).
59
What is the function of vascular tissue in plants?
Vascular tissue is responsible for transporting water, minerals, and nutrients throughout the plant.
60
What is the function and structure of xylem?
Xylem moves water and dissolved minerals upward through the plant.
Xylem cells are dead when mature (lack cytoplasm).
Xylem cells include vessels and tracheids.
61
What is the function and structure of phloem?
Phloem moves sugars and other nutrients in solution throughout the plant.
Phloem cells are alive when mature.
Phloem cells include sieve-tube elements and companion cells.
62
What are the general characteristics of ground tissue in plants?
Ground tissue makes up most of the plant body.
It functions in photosynthesis, storage, and support.
Includes parenchyma, collenchyma, and sclerenchyma cells.
63
What are the characteristics of parenchyma cells?
Parenchyma are the most abundant cell type in plants.
They have thin-walled, flexible cells.
Function in photosynthesis, storage, and tissue repair.
64
What are the characteristics of collenchyma cells?
Collenchyma cells have unevenly thickened cell walls.
They provide flexible support.
Found mainly in young stems and petioles.
65
What are the characteristics of sclerenchyma cells?
Sclerenchyma cells provide support, strength, and protection.
Dead when mature and have thick cell walls with lignin.
Found in fibers, nutshells, and seed coats.
66
What are the general characteristics of dermal tissue in plants?
Dermal tissue covers and protects the plant.
It serves as the outermost layer of the plant's body
67
What is the structure and function of the cuticle?
The cuticle is a waxy coating found on leaves and stems.
It protects the plant and prevents water loss.
68
What is the structure and function of the epidermis?
The epidermis is a single layer of cells.
It provides protection to the plant.
69
What is the function of stomata?
Stomata are tiny holes, mainly on leaves, for gas exchange.
In leaves, both photosynthesis and cellular respiration occur, but the predominant movement is CO₂ in and O₂ out.
In other plant parts (except stomata), only cellular respiration occurs, so O₂ in and CO₂ out.
70
What is the function of guard cells?
Guard cells surround the stomata.
They control the opening and closing of the stomata, regulating gas exchange and water loss.
71
Where are terminal buds located, and what is their function?
Terminal buds are located at the shoot tips.
They are responsible for primary growth, helping the plant grow in length.
72
Where are axillary buds located, and what is their function?
Axillary buds are located not at the shoot tips but in the angles formed between the stem and leaf.
They have the potential to develop into branches or flowers.
73
What are nodes, and what is their function?
Nodes are areas on the stem where leaves attach.
They are critical for the development of axillary buds and branches.
74
What are internodes, and what is their function?
Internodes are the sections of the stem between the nodes.
They allow for elongation of the plant stem.
75
What are the characteristics of the root system in a flowering plant?
The root system includes the taproot and lateral roots.
It is responsible for support and food storage.
Root hairs are present to aid in water absorption.
76
What is the function of the taproot in the root system?
The taproot is the main root that grows deep into the soil.
It provides support and stores food for the plant.
77
What is the function of lateral roots in the root system?
Lateral roots branch off from the taproot.
They help with support and food storage.
78
What is the function of root hairs in the root system?
Root hairs increase the surface area of the roots.
They assist in water absorption from the soil.
79
What are the characteristics of the shoot system in a flowering plant?
The shoot system includes the stem, flowers, and leaves.
It is responsible for supporting the plant and carrying out vital functions like photosynthesis and reproduction.
80
What is the function of the stem in the shoot system?
The stem supports the leaves and flowers.
It transports and stores water and nutrients between the roots and other parts of the plant.
81
What is the function of the flower in the shoot system?
The flower is responsible for reproduction, producing seeds for the next generation.
82
What is the function of the leaf in the shoot system?
The leaf carries out photosynthesis, converting light energy into chemical energy and producing food for the plant.
83
What is the difference in the number of cotyledons (seed leaves) between monocots and eudicots?
Monocots have 1 cotyledon (seed leaf).
Eudicots have 2 cotyledons (seed leaves).
84
What is the difference in leaf vein pattern between monocots and eudicots?
Monocots have parallel leaf veins.
Eudicots have branched leaf veins.
85
How do the flower parts differ between monocots and eudicots?
Monocots typically have flower parts in multiples of 3.
Eudicots typically have flower parts in multiples of 4 or 5.
86
What is the difference in the vascular bundle arrangement in stems between monocots and eudicots?
Monocots have scattered vascular bundles in the stem.
Eudicots have vascular bundles arranged in a ring in the stem.
87
What is the difference in root development between monocots and eudicots?
Monocots have fibrous root systems.
Eudicots typically have a taproot system.
88
How do pollen grains differ between monocots and eudicots?
Monocots have 1 pore in the pollen grain.
Eudicots have 3 pores in the pollen grain.
89
What is the difference in secondary growth between monocots and eudicots?
Monocots generally do not have secondary growth (they don’t form wood).
Eudicots often have secondary growth and can form wood.
90
What are some common examples of monocots?
Monocots include grasses, corn, wheat, rice, and lilies.
91
What are some common examples of eudicots?
Eudicots include roses, sunflowers, maples, beans, and tomatoes.
92
What are the general characteristics of nonvascular plants?
Nonvascular plants lack vascular tissue (xylem and phloem).
They need to live in moist environments because they rely on osmosis for water movement.
Examples: Mosses and Hornworts.
93
What are the general characteristics of seedless vascular plants?
Seedless vascular plants have vascular tissue (xylem and phloem).
They do not produce seeds but reproduce via spores.
Lycophytes (e.g., club mosses, also called ground pines) have simple leaves with a single vein.
Ferns have more complex leaves with many veins.
Examples: Club mosses (lycophytes) and Ferns (including Horsetails).
94
What are the general characteristics of gymnosperms?
Gymnosperms are seed plants that produce seeds, but not in flowers.
Their seeds are exposed, often found in cones.
Examples: Cycads and Ginkgoes.
95
What are the general characteristics of angiosperms?
Angiosperms are seed plants that produce seeds within a flower's ovary.
They are the largest group of plants and produce fruits.
Examples: Palms and Trees (flowering plants).
96
What is molecular systematics, and how is it used?
Molecular systematics involves comparing DNA sequences or amino acid sequences of proteins to construct phylogenetic trees.
Example: A phylogenetic tree based on molecular data is used to study the evolutionary relationships between bears, raccoons, weasels, and pandas.
97
What does cladistics use to construct phylogenetic trees?
Cladistics uses shared characters (traits or features) to construct phylogenetic trees. These characters are features that are inherited from a common ancestor.
98
Can phylogenetic trees change?
Yes, phylogenetic trees can change as new data (like molecular data) becomes available or as new discoveries are made, which can lead to revisions in the tree’s structure.
99
What is a clade and what do all members of a given clade share?
A clade is a group of organisms that includes a common ancestor and all of its descendants.
All members of a clade share shared derived characteristics that originated in their most recent common ancestor.
100
How is a monophyletic group different from a non-monophyletic group?
A monophyletic group (or clade) includes an ancestral group and all species descended from it.
A non-monophyletic group does not include all descendants of a common ancestor, meaning it leaves out some members.
101
What is a species?
A species is a type of organism whose members can breed with each other in nature and produce fertile offspring.
102
What is taxonomy?
Taxonomy is the science of naming and classifying organisms based on shared characteristics.
103
What are the different classification categories of organisms, from broadest to narrowest?
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
104
What is systematics?
Systematics is the science of classifying organisms based on their evolutionary relationships.
105
What is the purpose of a phylogenetic tree?
A phylogenetic tree is used to show the evolutionary relationships (history) between organisms, illustrating how they are related through common ancestry.
106
What are the parts of the stamen (male reproductive structure) in a flower?
The stamen consists of two parts:
Filament: the stalk that supports the anther.
Anther: the part that produces pollen (male gametes).
107
What are the parts of the carpel (female reproductive structure) in a flower?
The carpel consists of four parts:
Stigma: the sticky surface where pollen lands.
Style: the tube that connects the stigma to the ovary.
Ovary: the swollen base that contains ovules.
Ovules: the structures inside the ovary that develop into seeds after fertilization.
108
What is the process of male gamete formation in flowers?
A diploid cell inside the pollen sac of the anther divides by meiosis to produce 4 haploid microspores.
Each microspore divides by mitosis to form a pollen grain with 2 haploid cells:
Tube cell: forms the pollen tube.
Generative cell: forms the sperm cells.
Pollen sacs are located inside the anther.
109
What happens to the generative cell in pollen?
The generative cell divides by mitosis to produce 2 sperm cells.
110
What happens to the tube cell in the pollen grain?
The tube cell grows out of the pollen grain to form the pollen tube, which allows the sperm to travel to the ovule.
111
What is the process of female gamete formation in flowers?
A diploid cell inside the ovule undergoes meiosis to produce 4 haploid megaspores.
Only 1 megaspore survives and divides by mitosis to form a 7-celled embryo sac.
One of the cells becomes the egg cell.
Another cell contains 2 nuclei and becomes the endosperm mother cell.
112
What happens after fertilization in the female flower parts?
Both the egg and the endosperm mother cell will be fertilized by the sperm cells from the pollen grain.
113
What is pollination, and how does it occur?
Pollination is the delivery of pollen from the anther to the stigma.
Pollen is typically transferred by insects.
114
What happens after pollen is transferred to the stigma?
The 2 sperm cells in the pollen travel down the pollen tube.
One sperm fuses with the egg to form a diploid zygote.
The other sperm fuses with the endosperm mother cell to form a triploid endosperm.
115
What happens during the development of the plant embryo?
The zygote divides by mitosis to form embryo tissue.
The cotyledons (seed leaves) begin to develop.
116
What happens to the ovule as it matures?
The ovule (with the embryo) develops into a mature seed.
As the embryo matures, the seed loses most of its water and forms a hard seed coat, making the embryo dominant.
117
What is a fruit?
A fruit is a mature ovary that holds, protects, and disperses seeds.
118
What happens during seed germination?
Seeds take up water, expand, and rupture the seed coat.
Enzymes begin digesting stored nutrients, and the embryo starts to grow again.
