Chapter 2: Growth, Form and Function Flashcards
What is meristematic tissue?
Meristematic tissue is the only plant tissue that produces NEW cells by mitosis, rapidly growing to increase plant size, Apical meristem
What are the 3 stages of cell growth?
- Cell division (mitosis)
- Cell enlargement
- Cell Differentiation
Where do you find meristematic tissue
Usually in elongated bodies like the stem and root tips
What is parenchyma tissue?
Parenchyma tissue is the most prolific, sometimes considered 'padding'. Servers many functions that can include: • Water storage • Aeration • Food storage • Absorption • Protection
What is collenchyma tissue?
Collenchyma tissue provides the plant with support. The cells have thicker walls that contain cellulose.
What is sclerenchyma tissue?
Cells have much thicker walls and contain lignin.
Tissue matures only after growth is complete, then dies.
The woody walls of the cells remain, giving the plant support.
There are 2 forms of sclerenchyma tissue:
1. Fibres: long cells, often in bundles, that form wood.
2. Sclereids: round cells found in fruit like pears (gritty texture)
What are therophytes?
Annuals: they grow, flower, set seed, and die within one growing season.
What is the botanical name for biennials?
monocarpic: they complete their growth cycle in 2 years.
What are cryptophytes?
Any plan that grows from an underground structure. That includes bulbs, corms, and tubers.
• Geophytes: grow in dry soil
• Helophytes: grow in marshy soil
• Hydrophytes: grow in water
What is an epiphyte?
a plant that grows on another plant, without drawing nutrients from the host plant.
Describe a bulb
A type of bud that grows beneath the soil, with a short thick stem and tightly packed scales. An onion is a good example.
What is a corm?
A corm is a swollen underground stem that doesn’t have scales. Crocuses are corms.
Describe a tuber
A tuber is a storage organ, distinct from the rest of the plant, that grows underground. They can be separated from the main plant and regrown. Dahlias and potatoes are both tubers.
What is a rhizome?
Rhizomes are fleshy roots that are found on the surface, or just underground.
Bud morphology classifications
Terminal
Axillary
Adventitious
Bud classification by status
Accessory
Pseudoterminal
Dormant
Bud classification by function
Vegetative
Reproductive
Mixed bud
Where do you tend to find plants with scaly buds?
Cooler climates, modified leaves tightly enclose the bug to protect it. Scaly buds are often covered in a sticky gum for further protection.
What is apical dominance?
The apical bud of many species produces growth hormones that gives it some control over the lateral buds lower down.
A good example is the pyramidal shape of a christmas tree.
Removing the apical bug can promote bushier growth.
What are epicormic buds?
They are adventitious buds that lay dormant under the bark of some woody species.
These are usually triggered by hard pruning or when propagating by cuttings.
Who was Robert Fortune
Introduced tea plants to India
What are contractile roots?
They are roots found on bulbs and corms, that pull the them deeper into the soil. They work be expanding and contracting.
What are haustorial roots?
These are produced by parasitic plants. They penetrate the tissues of the host plant to take water and nutrients.
Where would you expect to see knee roots?
In swampy conditions. They grow upwards, and have breathing pores for the exchange of gases. This allows the plant to survive underwater.
What are the main functions of plant stems?
- Support and elevation of the leaves, flower, and fruit.
- Transport of fluids around the plant via vascular system.
- Storage of nutrients.
- Production of new tissue from buds and shoots.
Richard Spruce
19thC explorer of the Amazon.
Describe a bulb
A very short stem with a growing point, enclosed by thick fleshy modified leaves called scale leaves. Examples include daffodils, onions, and lilies.
Describe a corm
A corm is a swollen underground base of a solid stem, which is surrounded by protective scale leaves. The plants energy is stored in the stem, not the scales as in a bulb.
Describe a tuber
A tuber is a swollen underground end of a stem. The have eyes (a cluster of buds and a leaf scar). Plants with tubers include potatoes, begonias, and cyclamen. Note that some plants, like dahlias, are root tubers.
What is the difference between a rhizome and a stolon?
Rhisomes and stolons are both stems that grow on or just below the surface of the soil. Rhizomes are the main stem of the plant, while stolons arise from the main stem and new plants are produced at the ends.
