Structure Of Flowering Plants Flashcards
What are the functions of roots?
Anchors the plant in the soil
Absorbs water and mineral salts [root hairs]
Store food eg, carrots
What are the two types of roots?
Tap roots, fibrous roots
What is a tap root and give examples
Consists of a main root that develops from the initial root that emerged from the seed [radicle] eg, most dicots, dandelion and wallflower
What is a fibrous root and give examples
Formed when the radicle dies away, leaving a group of equal sized roots that emerge from the base of the stem eg, monocots, grasses and daffodils
What are adventitious roots and give examples
Roots that do not develop from the radicle, said to grow in strange places eg, fibrous roots, the roots at the base of an onion
What are the zones in a root?
Zone of protection
Meristems
Zone of elongation
Zone of differentiation
What is the zone of protection?
The root cap protects the root cells as they push through the soil
What are the meristems and where are they found?
Allow plants to grow. Apical meristems, found in root tip and in shoot tip. Others found around edge of some plant stems, leaves and fruit
What is the zone of elongation?
New cells are formed by meristem they are small in this zone, plant growth regulators [auxins] stimulate cells to grow longer
What is the zone of differentiation
Elongated cells, which are similar, develop into different types of tissue
What are the three tissues found?
Dermal tissue, Ground tissue and Vascular tissue
What are the functions of the stems?
Support the aerial parts of the plant
Transport water and minerals from roots to leaves
Transport food from leaves to root
Sometimes stores food
What is the main part of the shoot?
Stem
What are herbaceous plants?
Plants that do not contain wood [or lignin]
What are woody plants?
Plants that contain wood [or lignin]
What are nodes?
The points where leaves emerge from
What is an internode?
The part of the stem between two nodes
What is an apical bud?
Found at the tip of the stem. Causes the stem to grow at growing tip.
What happens if an apical bud is removed?
If removed, low bushy plant will form
What is an axil?
Is the angle between a leaf and a stem
Where are axillary or lateral buds located?
At each axil
What do axillary or lateral buds do
These buds produce new growth such as branches or flowers
What are lenticels?
An opening for gas exchange [02 in, c02 out]
What is stomata?
An opening for gas exchange [c02 in 02 out]
What does the distance between two sets of scale scars represent?
One year of growth
What are leaf scars?
Where the leaf has fallen
What will the apical bud do in winter
Produce following years growth
The tissue location in dicot stem, where is the xylem and phloem?
The phloem is on the outside, and the xylem is on the inside
What are the functions of leaves?
Leaves make food [photosynthesis]
Exchange gases [take in co2, release o2]
Leaves lose water [transpiration]
Stores food [lettuce, cabbage often consumed by humans + animals]
What does transpiration in the leaf allow?
Allows fresh water and mineral salts to be taken into plant
Where are leaves attached to the stems?
At a node
What is a petiole?
Stalk of a leaf
What is a sessile
Leaves that do not have a petiole [joined directly to the stem]
What is lamina
Leaf blade - leaf is flattened
Where does the petiole continue
It continues through the lamina as the midrib
What emerges from the midrib?
Veins, and are clearly seen in lamina.
What parts of the leaf contains xylem and phloem
The petiole, midrib and veins
What does venation mean?
The patterns of veins
What is parallel venation and where would you find it?
Veins run alongside eachother eg, monocots
What is net/reticulate venation and where would you find it?
Veins that form a branching network throughout lamina eg, dicots
When meristematic tissue divides, what happens?
It produces new flow which differentiate
What are the functions of dermal tissue?
Protection
Root hairs are extensions of the epidermis at root tips and are designed to absorb water and minerals
The epidermis of leaves + most stems is coated with a waxy cuticle to prevent water loss
What are the functions of ground tissue?
Photosynthesis, stores food and waste, gives strength and support to plant
What are the functions of vascular tissue?
Transport materials thoughout plant
What is xylem?
Xylem is a dead tissue that transports water and minerals from roots to leaves
What are xylem tracheids?
Type of xylem that overlap and allow water to pass from tracheid to tracheid through thin parts of the walls called pits.
What are xylem vessels?
Type of xylem that are tubular structure formed when a number of cells join end to end. Their end walls break down to from a continuous tube, they have pits in their side walls to allow water to pass from one vessel to another
What is lignin?
It’s a hard strong chemical found in plant cell walls which make the walls very strong
What are the differences between xylem tracheids and vessels?
Tracheids are more primitive than vessels
Where is xylem found?
In roots, stems, leaves and flowers in vascular bundles
What is phloem?
It’s composed of sieve tubes and companion cells and it transports food made by photosynthesis in leaves to rest of plant
What are sieve tubes?
Long tubular structures that from when sieve tube elements join end to end
The end walls develop pores which allow the passage of materials from one element to the other
The end walls are known as sieve plates
What are the walls of the sieve tube elements made of?
Cellulose, lignin is not present
What is the function of sieve tubes?
Transport food made by photosynthesis from the leaves to rest of plant
What is the function of companion cells?
They control the activities of the sieve tube elements
Where is phloem found?
In vascular bundle of roots, stems, leaves and flowers
Monocot features
One cotyledon in the seed Mostly herbaceous plants Long and narrow + Parallel venation Vascular bundles are scattered Flowering parts arranged in groups of three
Dicot features
Two cotyledons in each seed
May be herbaceous or woody
Net venation and broad leaves
Vascular bundles are arranged in ring around inside of stem
Flowering parts are arranged in groups of fours or fives
What is a cotyledon?
It is a leaf in the seed specialised for food storage
Differences between xylem and phloem
Xylem is dead; phloem is alive
Xylem carries water and miners ; phloem carries food
Xylem has lignin ; phloem does not
Xylem has no companion cells, phloem does
Xylem has no nucleus, phloem
Which tissue has different location in young root?
Vascular
Why is it desirable to cut the section as thinly as possible?
To ensure light an pass through
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
How did you prepare this section
Cut short thin section of stem using wet scalpel and place in petri dish of water
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
Why are herbaceous plants used?
They are easier to cut
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
Why do you wet the blade?
To reduce friction
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
Safety precaution
Cut the stem away from fingers to prevent injury
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
Why are the cut sections stored in a Petri dish?
To prevent them dehydrating
Name two compounds that leave the plant through lenticles
Carbon dioxide, Water
Where precisely is the vascular tissue found in roots?
In the centre
Draw labelled diagram to show the detailed structure of the two vascular tissues of plants
Phloem and xylem vessel
Which of the two vascular tissues is composed of living cells?
Phloem
What is the function of meristematic tissue?
Mitosis
What is meant by the term “monocotyledonous”
One seed leaf
Name the structure that are scattered in monocot stem
Vascular bundles
How do you know from the diagram that the section is taking from a stem?
More than one vascular bundle
How do you know from the diagram that the section is taken from a monocot?
Vascular bundles are scattered
How do you know from the diagram that the section is taken from a root?
Only one vascular bundle
How do you know from the diagram that the section is taken from a dicot?
Vascular bundles arranged in a ring
Describe in detail how you prepared a microscope slide of a transverse section of the stem of a dicotyledonous plant?
- Cut short thin section of stem using a wet blade to reduce friction away from hand to prevent injury
- store the cut sections of stem in Petri dish of water to prevent dehydration and then transfer thin section to microscope slide using forceps.
- add a few drops of water and coverslip at an angle to eliminate air bubbles
The walls of vessel and tracheids are reinforced with hard material, what is it?
Lignin
Where precisely is this vascular tissue [xylem] found in the stem of a young dicot plant?
Vascular bundles
In which of the tissues are sugars mainly transported?
Phloem
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
What did you use to cut the section?
Blade
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
How did you support the stem while you were cutting the section?
Using hand
In relation to an investigation you carried out to prepare and examine with a microscope a transverse section of a dicot stem -
How did you transfer the section to a microscope slide?
Forceps
What is the function of stoma?
Allow gas exchange and transpiration
Name a carbohydrate you’d expect to find in the modified leaves of the onion?
Starch
Name a factor that influences the diameter of stoma?
Co2 concentration
