Plant Science 1: External Parts Of The Plant Flashcards
What is the function of roots in a plant?
Anchoring the plant, absorbing water and nutrients, storing nutrients, enabling propagation
Roots can also help plants survive in adverse conditions.
What specialized organs can roots develop to store nutrients?
Tubers or potatoes
These adaptations help plants survive winter or dry seasons. Daucus carota (carrot) store food in enlarged tap roots.
What are the primary external parts of a plant?
Stems, leaves, and roots
Flowers are temporary in a plant’s life cycle.
What type of root system do eudicots primarily have?
Tap root system
The tap root develops from the radicle, the embryonic root in the seed.
How does a tap root benefit eudicots?
Enables deep penetration into the ground to draw up water and nutrients
Tap roots can also store nutrients, as seen in carrots and parsnips.
What happens to lateral roots in some herbaceous perennials?
Lateral roots may take over and the tap root disappears
This adaptation can enhance nutrient uptake and stability.
What characterizes the root system of monocots?
Fibrous root system without a tap root
Monocots’ roots start at the base of the stem and can be branched.
True or False: Monocots can repair their roots.
False
Monocots have no growth tissue behind the tip of their roots.
Fill in the blank: Eudicots start off with a _______.
tap root
This root system is fundamental for nutrient and water absorption.
What is a key feature of monocots regarding root production?
Can produce new root mass from the base of the stem
This allows for regeneration but limits depth penetration.
What happens to the cells after they are formed at the root tip?
The cells elongate, causing the root to grow
This elongation is crucial for root development.
What is the function of the root cap?
Protects the root tip as it pushes through the soil
The root cap is essential for safe passage through soil.
How are the cells of the root cap maintained?
The cells are constantly replaced by new ones
Old cells break up and help lubricate the root’s passage.
What are root hairs?
Elongated cells just behind the root’s growing tip that increase the surface area of roots
Root hairs are short-lived and can number between 200-400 per square millimeter.
What role do root hairs play in plants?
They bring roots into contact with more water and nutrients
They significantly enhance the plant’s ability to absorb essential resources.
What are mycorrhizal fungi?
Fungi that associate with plant roots to increase surface area for nutrient access
They are particularly important for helping woody plants in poor soils access nutrients like phosphorus.
What can contribute to transplanting shock in plants?
Damage to root hairs and mycorrhiza during transplantation
Minimizing this damage is crucial for establishing new plantings.
What is the primary role of stems in plants?
To support other plant organs and maximize light interception
This support helps leaves to maximize photosynthesis.
How do stems assist in plant reproduction?
By holding flowers in positions for effective pollination and seed distribution
This positioning increases the chances of successful reproduction.
What does the term ‘shoot’ refer to in botany?
The stem and its attached leaves and buds
The shoot is crucial for the overall growth and function of the plant.
What type of tissue does stem tissue include?
Supportive tissue and vascular tissue
Vascular tissue is responsible for transporting water and nutrients throughout the plant.
What are the two main structural components of eudicot plants?
Leaves and buds
Leaves and buds are produced at nodes, with spaces between nodes referred to as internodes.
What is a bud?
A compact package of embryonic shoot consisting of immature leaves and dormant meristem tissue
Buds are capable of becoming a growth point.
Where are buds typically found?
Woody plants from temperate climates
In perennials, buds may be absent or invisible at ground level, and are usually absent from plants in warmer climates.
What are the two types of buds?
Apical (terminal) buds and axillary (lateral) buds
Apical buds are located at the tip of a shoot, while axillary buds are located at the sides.
What is the significance of leaf scars?
They show where a leaf or fruit has been attached
Leaf scars can be useful in identifying plants in winter from bare stems.
What are nodes in plant stems?
Points where leaves and buds are produced
Nodes are contrasted with internodes, the spaces between them.
What is the primary function of apical buds?
To grow next spring
Apical buds are responsible for the upward growth of the plant.
What distinctive feature can be observed on the stems of Aesculus hippocastanum (horse chestnut)?
Large leaf scars
These scars are distinctive and can aid in plant identification during winter.
What are lenticels?
Little breaks on the surface of the stem or trunk that allow gaseous exchange
Lenticels enable respiration which needs oxygen and have different shapes depending on the species.
What is the primary function of lenticels in woody plants?
To allow gaseous exchange, particularly enabling respiration
This process allows air to diffuse through the bark to living cells below.
How can lenticels be useful in identifying trees and shrubs?
They have different shapes depending on the species
This characteristic can be particularly helpful in winter when leaves are absent.
What do growth rings indicate in woody plants?
Where one year’s growth has ended and the next year’s has begun
This is marked by the bud scale scar where terminal bud scales were attached.
What is a bud scale scar?
The mark left where the terminal bud scales were attached to the shoot
It indicates the transition between one year’s growth and the next.
True or False: Growth rings can be recognized in all types of plants.
False
This method only works with woody plants that form buds.
What type of leaves do ferns have?
Ferns have fronds, which can be delicate-looking and very sub-divided, or plain and shiny.
Describe the general characteristics of monocot leaves.
Monocot leaves are generally narrow with parallel veins, rarely having leaf stems (petioles).
What is the typical structure of eudicot leaves?
Eudicot leaves usually have broad leaves with reticulate veins and leaf stalks (petioles).
What is the term for the main structure of a leaf?
The blade of a leaf is called the lamina.
What are simple leaves?
Simple leaves have only one single leaf blade.
What defines compound leaves?
Compound leaves are composed of multiple leaflets arranged in various ways.
What is the arrangement of leaflets in pinnate compound leaves?
Pinnate leaves have leaflets arranged along a central stalk.
Describe the arrangement of leaflets in palmate compound leaves.
Palmate leaves have leaflets arising from a single point on the petiole.
How can you distinguish between compound leaves and simple leaves?
Look for an axillary bud; if present, it is a leaf; if absent but present at the base of the leaf stalk (rachis), they are leaflets.
What leaf arrangement has one leaf at each node?
Alternate arrangement
In which leaf arrangement do leaves occur in opposite pairs at right angles?
Decussate arrangement
What is the term for leaves that surround some flowers and attract pollinators?
Bracts
What are scale leaves?
Small brown papery-textured leaves forming the outer layer of buds
Fill in the blank: Some perennials, such as ________, replace all their leaves within a few weeks in late winter.
hellebores
What type of leaf arrangement features three or more leaves per node?
Whorled arrangement
What is the primary function of flowers?
Essential to sexual reproduction, site for pollination, give rise to seed and fruit
How do monocotyledons differ from eudicotyledons in flower structure?
- Monocotyledons: flower parts arranged in threes or multiples of three
- Eudicotyledons: flower parts arranged in fours, fives, or multiples of these
What is the botanical family name for grasses?
[Poaceae]
What is the flower stalk called?
Pedicel
What is the term for the stalk of a flower head?
Peduncle
What is a bract?
A leaf-like structure sometimes found at the base of a flower or surrounding it.
What does the receptacle do in a flower?
Supports and acts as a base for the rest of the flower.
What is the function of sepals?
Protects the flower before it opens.
What is the calyx?
All the sepals together.
Where are nectaries located in flowers?
At the base of the petal.
The outer visible part of the flower bud is formed by _______.
Sepals
What is the primary function of the bract?
To surround or support the flower.
What is the structure that forms the outer protective layer of a flower bud?
Calyx
What is the collective name for all the petals of a flower?
Corolla
The calyx plus the corolla are known as the perianth.
What is the male sexual organ of a flower called?
Stamen
The stamen includes the anther and the filament.
What is produced in the anther?
Pollen
The anther is part of the stamen.
What connects the anther to the receptacle?
Filament
The filament positions the anther for effective pollen dispersal.
What is the female sex organ of a flower called?
Carpel
The carpel consists of the stigma, style, and ovary.
What is the sticky, receptive surface at the end of the style called?
Stigma
Pollen lands on the stigma and grows down into the ovary.
What part of the carpel contains the ovules?
Ovary
The ovary often develops into the fruit after fertilization.
What are the female sex cells in a flower called?
Ovules
Ovules develop into seeds if fertilization occurs.
What is an inflorescence?
A collection of flowers on the same stalk (the peduncle)
In ordinary speech, an inflorescence is often referred to as a ‘flower head’.
Why do flowers grow in colonies?
To make the visits of pollinating insects as efficient as possible
Massing flowers together allows insects to spend less time traveling from flower to flower.
What role do the brightly coloured bracts play in Euphorbia polychroma?
They attract pollinators, performing the job usually done by petals.
What family do daisies belong to?
Asteraceae.
What do ovules turn into once successfully fertilised?
Seeds
The ovary and often other parts of the floral structure turn into supporting structures.
What is the visual significance of seed heads, berries, and other fruit in gardens?
They provide visual interest in autumn and winter gardens
Additionally, they are an important wildlife resource.
What are carnivorous plants?
Plants that attract, ensnare, and digest insects to obtain nutrients
Examples include the Venus fly trap (Dionaea muscipula), which grows in nutrient-poor environments.
What nutrients do carnivorous plants primarily obtain from insects?
Mostly nitrogen
Nitrogen is often in short supply in the bogs and marshes where these plants grow.
Why is seed dispersal important for plants?
It allows new plants to colonize new areas and habitats, often many miles away
This can lead to the spread of a plant species and potentially contribute to invasiveness.
What are some methods of seed dispersal?
Plants have evolved many methods, including wind, water, and animal dispersal
Each method is adapted to specific habitats.
Give an example of a plant that uses wind dispersal.
Taraxacum officinale (dandelion)
The dandelion has modified fruit structures that form parachutes for effective dispersal.
What type of structure do some seeds have to aid in wind dispersal?
Wings or parachutes
Examples include the wings of Acer campestre (field maple) and the parachutes of Clematis vitalba (Old man’s beard).
What is the main feature of clematis flowers?
The prominent bracts.
During which seasons do seed heads create a distinct atmosphere in the garden?
Autumn and early winter
