Stem Adaptations - Topic 1 (Plant Science II), Element 2 Flashcards
What are two examples of secondary thickening in stems?
Wood and cork
Secondary thickening involves the production of wood and cork, which increases the girth of the stem.
List three physical defensive adaptations of stems.
- Thorns
- Prickles
- Hairs
These adaptations help protect plants from herbivory and environmental stress.
What is the function of tendrils in plants?
Support and climbing
Tendrils allow plants to attach and climb on structures for better light access.
What is the role of stolons in plant propagation?
Asexual reproduction through horizontal stems
Stolons allow plants to spread and produce new individuals from the parent plant.
Na
Na
Fill in the blank: The adaptations of stems can enhance _______ for plants.
Light access
Enhanced light access is one of the advantages of stem adaptations.
What horticultural use do climbing plants serve?
Support for vertical growth
Climbing plants utilize stems to reach light and can be decorative in gardens.
True or False: Both Eudicots and Monocots produce true wood.
False
Only Eudicots produce true wood; Monocots do not form a cambium ring.
What is the primary function of stems in plants?
- Support
- Transport
- Storage
Stems provide mechanical strength, connect plant parts, and facilitate the movement of water and nutrients.
What is apical dominance?
The phenomenon where the apical bud suppresses axillary bud growth
Apical dominance allows plants to grow taller and more efficiently by prioritizing the main stem.
Name two types of reaction wood in trees.
- Compression wood (Gymnosperms)
- Tension wood (Angiosperms)
Reaction wood helps trees maintain their structure against wind and gravity.
What is the function of the bark in woody plants?
- Protects vascular system
- Insulation
- Prevents water loss
Bark serves multiple protective and insulating roles for woody plants.
Fill in the blank: Epicormic buds are hidden beneath the _______.
Bark
Epicormic buds can sprout new growth after damage to the tree.
What is the role of lenticels on stems?
Allow gas exchange
Lenticels are pores that enable oxygen and carbon dioxide to enter and exit the stem.
What is the significance of cork in plant physiology?
Seals off damaged areas and protects against pathogens
Cork forms a protective layer over exposed tissues after injury.
True or False: Rhizomes are a form of stem adaptation that allows for water storage.
False
Rhizomes primarily serve as a means of asexual reproduction and energy storage, not specifically for water storage.
What are the two main types of plant growth?
- Primary growth
- Secondary thickening
Primary growth increases length, while secondary thickening increases girth.
What are the benefits of leaving dead stems and seedheads in the garden?
- Provides habitats for invertebrates
- Supports biodiversity
Dead plant material is crucial for various organisms, especially during winter.
What is the purpose of pruning in horticulture?
Promotes bushier growth by encouraging axillary bud development
Pruning removes the apical bud, leading to increased side branching.
List three types of stem cuttings used in propagation.
- Softwood
- Semi-ripe
- Hardwood
These types of cuttings utilize the totipotency of stem tissues to develop new roots.
What are stem adaptations in plants?
Secondary thickening, physical defence (thorns), tendrils, twining stems, stolons, tubers, runners, glandular hairs, corms, rhizomes
Stem adaptations enhance plant survival and reproduction.
List the advantages of stem adaptations for plants.
- Defence from herbivory
- Support
- Enhanced light
- Water storage
- Carbohydrate storage
- Resilience to weather conditions
These adaptations help plants thrive in various environments.
What is the epidermis in plants?
The outer layer of cells of most plant parts
The epidermis is crucial for protection and water retention.
What adaptation helps plants shield from UV rays and conserve water?
Trichomes (hairs)
These hairs can also deter herbivores.
What are prickles?
Spiky outgrowths of the epidermis
Examples include those found on Rosa species.
True or False: The waxy cuticle in some plants helps conserve water.
True
It provides extra protection against environmental stresses.
What is a thorn?
A modified stem structure that protects plants from herbivores
Thorns can also provide homes for ants in some species.
What are essential oils in plants used for?
Defence from herbivores and attracting pollinators
They can deter herbivores with strong smells.
What are tendrils in climbing plants?
Modified leaves or stems that twine around supports
They help plants reach light and height.
What is perennation?
Being able to survive between one growing season and the next
Essential for plants to endure unfavorable conditions.
What are rhizomes?
Thickened, underground stems
They serve as a means of vegetative propagation.
Fill in the blank: __________ are stems that grow horizontally along the ground.
Stolons
Stolons can root at nodes to propagate new plants.
What is the difference between stem tubers and root tubers?
Stem tubers have buds, while root tubers do not
Buds on stem tubers can grow into new shoots.
What type of plant structure is a corm?
A compressed stem
Corms can produce cormels for propagation.
What is the function of glandular hairs in some plants?
They can produce oils and facilitate carnivory
Sticky hairs trap insects for digestion.
True or False: All plants of a twining species twine in the same direction.
True
This characteristic aids in identification.
What are some horticultural uses of stem adaptations?
- Climbing plants
- Decorative adaptations
- Colonisation of areas
- Creation of habitats for wildlife
- Impact on planting styles
These uses enhance garden aesthetics and biodiversity.
