Plant Form And Function

1. What is morphological diversity?

Variation in size and shape of organisms within a population.

Differences in behavior exhibited by organisms within a community.

Genetic difference between individuals --initially influences an organism's genes heavily

Changes in an organism's physical appearance over its lifetime due to environmental factors.

Morphological diversity refers to the differences in physical characteristics within a population based on genetic variation.

Explanation

Morphological diversity refers to the differences in physical characteristics within a population based on genetic variation.

2. What is the primary function of roots? What other functions can modified roots serve?

--Underground part of a plant that anchors the plant and absorbs water and nutrients; conduct water and selected ions to the shoot and store material produced in the shoot for later use.
--snorkel: function in gas exchange --adventitious root: develops from the shoot system instead of the root system (ex: ivy plant roots help them cling to brick walls)

Modified roots only provide structural support to the plant

Roots do not absorb nutrients or conduct water to the shoot system

Roots solely serve as anchors for the plant

Roots have a variety of functions beyond anchoring and absorbing nutrients, including gas exchange and development in different parts of the plant.

Explanation

Roots have a variety of functions beyond anchoring and absorbing nutrients, including gas exchange and development in different parts of the plant.

3. What is the primary function of shoots? What other functions can modified shoots serve?

The main purpose of shoots is to provide a habitat for insects and other small organisms.

Above ground part and function to harvest light and elevate leaves fro maximum light exposure.
--cacti: water storage-- stolon (above soil) and rhizomes (below soil)-- asexual reproduction-- tubers: carbohydrate storage--Thorns: defense

Modified shoots primarily serve the function of absorbing nutrients from the soil.

Primary function is to store water.

Shoots primarily function to harvest light and elevate leaves for maximum light exposure. They can also serve as water storage, for asexual reproduction, carbohydrate storage, and defense mechanisms like thorns.

Explanation

Shoots primarily function to harvest light and elevate leaves for maximum light exposure. They can also serve as water storage, for asexual reproduction, carbohydrate storage, and defense mechanisms like thorns.

4. What is the primary function of leaves? What other functions can modified leaves serve?

Produce the fruits of the plant

Serve as reproductive organs for the plant

Appendages that project from a stem laterally to provide photosynthetic organs.
--cactus spines: protect the stem--onion leaves: store food--Aloe vera leaves: store water--Pea tendrils: aid in climbing--Poinsetta leaves: attract pollinators--Pitcher plant leaves: trap insects--Flowerpot plant leaves: collect soil

Absorb water and nutrients from the soil

Leaves primarily function as photosynthetic organs, but can also serve various other functions through modifications like protection, storage, climbing assistance, attracting pollinators, trapping insects, or collecting soil.

Explanation

Leaves primarily function as photosynthetic organs, but can also serve various other functions through modifications like protection, storage, climbing assistance, attracting pollinators, trapping insects, or collecting soil.

5. What is an example of how environment creates phenotypic plasticity of two trees that began with similar genes?

One grown in fertile soil and one grown in barren soil (similar genes).

One grown with regular watering and one grown with minimal watering (similar genes).

One grown in light and one dark (similar genes).

One grown in light-open sunny habitat--- no light competition
One grown in a forest-- competition for light is intense
example of how environment creates phenotypic plasticity of two trees that began with similar genes

One grown in different continents with different climates (similar genes).

The correct answer highlights how the environment (light conditions) impacts the growth and development of trees with similar genes. The other options do not accurately capture how environmental factors can lead to phenotypic plasticity in trees.

Explanation

The correct answer highlights how the environment (light conditions) impacts the growth and development of trees with similar genes. The other options do not accurately capture how environmental factors can lead to phenotypic plasticity in trees.

6. Where are the living cells and where are the dead cells?

Similar distribution of living cells in sapwood and heartwood. Wet wood contains a mix of living and dead cells. Discolored wood and false wood have no living cells. Cell walls are made up of cellulose, lignin, hemicellulose.

More living cells in sapwood No living cells in heartwood , wet wood, discolored wood and false wood
Wood is highly ordered arrangement of living, dying and dead cells-- cell wall are made up of cellulose, lignin, hemicllulose.--Vessel/tracheids are very large compared to parenchyma cells --Vessels, fibers and tracheids live only a short time
Volume basis-- sapwood is mostly dead#-of-cell basis-- sapwood is mostly alive

Cell walls are primarily made up of proteins in both sapwood and heartwood. Cell types like parenchyma cells make up the majority of the wood composition. Vessels, fibers, and tracheids have a long lifespan in both sapwood and heartwood. Volume basis - both sapwood and heartwood have similar distribution of living and dead cells. #-of-cell basis - both sapwood and heartwood have a balanced distribution of living and dead cells.

More living cells in heartwood. No living cells in sapwood, wet wood, discolored wood, and false wood.

7. What properties of meristem cells permit plants to grow continuously throughout life?

Meristem cells do not undergo cell division.

Meristem cells are only active during the winter season.

Meristem cells are specialized for photosynthesis.

--key for plant growth and development--site of cell division--cells are undifferentiated undifferentiated cells: retain the ability to undergo mitosis and produce new cells

Meristem cells play a crucial role in plant growth by being the site of cell division and consisting of undifferentiated cells that can continuously undergo mitosis, allowing plants to grow throughout their life.

Explanation

Meristem cells play a crucial role in plant growth by being the site of cell division and consisting of undifferentiated cells that can continuously undergo mitosis, allowing plants to grow throughout their life.

8. What is the relationship between apical meristem, axillary meristem, and branching?

Axillary meristem is located at the top of each root and shoot, apical meristem develops into lateral branches, and branching is a result of apical meristem activity.

Apical meristem- located at the top of each root and shoot-Group of undifferentiated plant cells that is responsible for primary growth
Axillary meristem: -also known as the bud apical meristem-may develop into a lateral branch
Branching:-axillary meristems lead to branching whereas apical meristems lead to vertical growth.

Apical meristem is responsible for lateral growth, axillary meristem leads to primary growth, and branching is influenced by both types of meristems equally.

Branching is solely controlled by apical meristems, axillary meristem leads to vertical growth, and apical meristem is responsible for lateral growth.

The correct relationship between apical meristem, axillary meristem, and branching is that apical meristem is responsible for primary growth, axillary meristem may develop into lateral branches, and branching is influenced by axillary meristems leading to lateral growth.

Explanation

The correct relationship between apical meristem, axillary meristem, and branching is that apical meristem is responsible for primary growth, axillary meristem may develop into lateral branches, and branching is influenced by axillary meristems leading to lateral growth.

9. Under what environmental conditions might there be selective pressure to promote internode elongation? Inhibit internode elongation?

Promote internode elongation--in an environment where trees are close to one another and light competition is intense (trees taller, internodes longer)
Inhibit internode elongation-promoted in environments where there is no competition for light (shorter trees, shorter internodes)

Inhibit internode elongation--in an open field with ample sunlight

Promote internode elongation--in cold climates with short growing seasons

Promote internode elongation--in an environment with limited water supply

Internode elongation is influenced by the level of light competition among trees. When trees are close together and light competition is intense, there is selective pressure to promote internode elongation to help trees reach sunlight. On the other hand, in environments with no competition for light, internode elongation may be inhibited as there is no need to grow longer to access sunlight.

Explanation

Internode elongation is influenced by the level of light competition among trees. When trees are close together and light competition is intense, there is selective pressure to promote internode elongation to help trees reach sunlight. On the other hand, in environments with no competition for light, internode elongation may be inhibited as there is no need to grow longer to access sunlight.

10. Under what environmental conditions might there be selective pressure to promote branching? inhibit branching?

Promote Branching-environments with limited sunlight and dense competition

Promote Branching-environments of open areas where there is a lot of sunlight and no competition
Inhibit Branchingthere is high competition for sunlight because the plant has to focus on certain branches getting tall in order to compete for sunlight

Promote Branching-environments with high competition for water and nutrients

Inhibit Branching-environments with ample sunlight and minimal competition

The correct answer highlights the relationship between environmental conditions, sunlight availability, and competition in promoting or inhibiting branching in plants.

Explanation

The correct answer highlights the relationship between environmental conditions, sunlight availability, and competition in promoting or inhibiting branching in plants.

11. Why do the sieve elements of the phloem require companion cells? Why don't the tracheids and vessel elements of the xylem require companion cells?

Sieve elements require companion cells because they are water-conducting cells.

Companion cells lack nuclei, chloroplasts, and other major organelles.

Sieve elements-long, thin cells that have perforated ends (sieve plates)-responsible for transporting sugars and other nutrients -lack nuclei/chloroplasts/ most other major organelles
Companion cells-contain all of the organelles normally found in a plant cell
-companion cells are not conducting cells that provide materials to maintain the cytoplasm and plasma membrane of sieve-tube members-Load and unload carbohydrates and other nutrients from the solution inside sieve-tube members
Tracheids-in all vascual plants-water-conducting cells -long, slender with tapered ends-pits (gap in primary and secondary cell wall)
Vessel Elements-shorter/wider-angiosperms-conducting cells-perforations ( opening that lacks primary cell wall, still has secondary cell wall)
-tracheids and vessel elements are DEAD at maturity and interact with fluids they conduct instead of the cytoplasm-don't need companion cells to maintain a cytoplasm or plasma membrane

Tracheids and vessel elements of the xylem require companion cells to transport sugars and other nutrients.

Sieve elements require companion cells due to their lack of key organelles and their need for material exchange, while tracheids and vessel elements do not require companion cells because they are already dead at maturity and do not possess a cytoplasm or plasma membrane to maintain.

Explanation

Sieve elements require companion cells due to their lack of key organelles and their need for material exchange, while tracheids and vessel elements do not require companion cells because they are already dead at maturity and do not possess a cytoplasm or plasma membrane to maintain.

12. What is the main function of dermal tissue?

Nutrient transport, support

Epidermal -complex tissue consisting of...1. epidermal cells2. guard cells3. trichome cellsFUNCTION: protection, gas exchange

Reproduction, energy storage

Photosynthesis, water absorption

Dermal tissue functions primarily in protection of the plant from external factors and in gas exchange through stomata and trichomes.

Explanation

Dermal tissue functions primarily in protection of the plant from external factors and in gas exchange through stomata and trichomes.

13. What is the main type of tissue found in plant stems, roots, and leaves?

Epidermal Tissue

Vascular Tissue

Parenchyma (sieve tube elements and companion cells)CollenchymaSclerenchyma (sclerids and fibers)

Meristematic Tissue

Ground tissue is responsible for storage, support, and photosynthesis in plants, making it a crucial type of tissue found in various plant structures.

Explanation

Ground tissue is responsible for storage, support, and photosynthesis in plants, making it a crucial type of tissue found in various plant structures.

14. What plant cell types produce lignin and how do plants benefit from lignin production?

Lignin is produced by leaf cells in plants and benefits in photosynthesis.

Plants produce lignin in their roots for anchoring purposes.

Plants that have secondary growth (sclerenchyma)Benefit due to...- protection-make plants vascular tissue conduct water efficiently-support through strengthening of wood

Only plants with primary growth produce lignin.

Plants that have secondary growth (sclerenchyma) are the ones that produce lignin because of the benefits it provides such as protection, efficient water conduction in vascular tissue, and support for strengthening wood.

Explanation

Plants that have secondary growth (sclerenchyma) are the ones that produce lignin because of the benefits it provides such as protection, efficient water conduction in vascular tissue, and support for strengthening wood.

15. What are the two types of growth in plants?

Basic Growth (dermal, ground, vascular)-expands overall size

Primary Growth (dermal, ground, vascular)-vertical growth (increases length of roots/shoots-cells derived from apical meristems FUNCTION: increase plants ability to absorb photons, acquire CO2, H2O and ions
Secondary Growth ( cock, secondary phloem, secondary xylem) (no dermal tissue)-increases widthFUNCTION: increase amount of conducting tissue available and provide structural support required for extensive growth

Horizontal Growth (dermal, ground, vascular)-increases length

Tertiary Growth (cock, secondary phloem, secondary xylem)-increases depth

Primary growth is responsible for increasing the length of roots and shoots, while secondary growth increases the width of plants by adding secondary phloem and xylem. The incorrect answers do not accurately describe the different types of growth in plants.

Explanation

Primary growth is responsible for increasing the length of roots and shoots, while secondary growth increases the width of plants by adding secondary phloem and xylem. The incorrect answers do not accurately describe the different types of growth in plants.

16. Label sections of stem?

1. cork cells2. cork cambium3. phelloderm4. secondary phloem5. vascular cambium (produces xylem and phloem)6. secondary xylem
Bark(all cells outside vascular cambium)1. Periderm (Cork cells, cork cambium, phelloderm)
Wood1. secondary phloem2. vascular cambium3. secondary xylem

1. Primary phloem2. Epidermis3. Mesophyll

The stem is made up of various sections including cork cells, cork cambium, phelloderm, secondary phloem, vascular cambium, and secondary xylem. Primary phloem, epidermis, and mesophyll are not part of the stem structure.

Explanation

The stem is made up of various sections including cork cells, cork cambium, phelloderm, secondary phloem, vascular cambium, and secondary xylem. Primary phloem, epidermis, and mesophyll are not part of the stem structure.

17. What is a shoot system?

The shoot system is primarily responsible for water absorption.

The shoot system includes only the roots of a plant.

Just getting light and getting light involves growing-plant needs CO2

The shoot system has nothing to do with plant growth.

The shoot system of a plant is crucial for capturing light energy, which is essential for photosynthesis. This system includes the above-ground parts of a plant, such as stems, leaves, and flowers. The shoots play a vital role in producing food and supporting the plant's growth.

Explanation

The shoot system of a plant is crucial for capturing light energy, which is essential for photosynthesis. This system includes the above-ground parts of a plant, such as stems, leaves, and flowers. The shoots play a vital role in producing food and supporting the plant's growth.

18. What is the main function of a root system?

Get nutrients and water from the ground

Store excess nutrients and water.

Control the growth of the plant.

Absorb sunlight for photosynthesis.

The root system of a plant primarily serves to absorb nutrients and water from the ground, providing essential resources for the plant's growth and development.

Explanation

The root system of a plant primarily serves to absorb nutrients and water from the ground, providing essential resources for the plant's growth and development.

19. Why do shoot and root systems vary based on species?

As a result of climate change and human intervention.

Because all plants are identical genetically.

Due to random mutations in their genetic code.

-Different needs-different environments (phenotypic plasticity)

Shoot and root systems vary based on species due to their different needs and the environments they adapt to, known as phenotypic plasticity.

Explanation

Shoot and root systems vary based on species due to their different needs and the environments they adapt to, known as phenotypic plasticity.

20. What are the main functions of parenchyma in ground tissue vs. vascular tissue?

Ground tissue parenchyma regulates gas exchange, while vascular tissue parenchyma assists in hormone production.

Ground tissue parenchyma is responsible for conducting water and minerals, while vascular tissue parenchyma stores excess sugars.

Ground tissue-store starch/photosynthetic
vascular-transport photosynthetic products (sieve tube elements/companion cells)

Ground tissue parenchyma provides structural support, while vascular tissue parenchyma aids in water absorption.

21. How does vascular cambium produce new cells?

New cells produced on the outside of the meristem---secondary phloem
new cells produced inside--secondary xylem

Vascular cambium does not produce new cells

New cells are only produced on the outside of the meristem

New cells are only produced inside to form secondary phloem

The vascular cambium produces new cells both on the outside (forming secondary phloem) and inside (forming secondary xylem) of the meristem, allowing for secondary growth in plants.

Explanation

The vascular cambium produces new cells both on the outside (forming secondary phloem) and inside (forming secondary xylem) of the meristem, allowing for secondary growth in plants.

22. Why are growth rings apparent in wood?

Wood absorbs sunlight differently in different seasons.

Wood growth is influenced by the moon phases.

Two different types of wood that look different-spring wood/summer wood
Spring wood would be much larger because there is a lot of moisture and spring wood and summer wood differ based on amount of water
spring-a lot of water
summer- less water

Growth rings form due to changes in temperature throughout the year.

Growth rings in wood are formed by the contrast between spring wood and summer wood, which differ in appearance and composition based on the amount of water available during each season. This results in visible rings that indicate the growth patterns of the tree.

Explanation

Growth rings in wood are formed by the contrast between spring wood and summer wood, which differ in appearance and composition based on the amount of water available during each season. This results in visible rings that indicate the growth patterns of the tree.