Plants Flashcards
Describe the external structure of a leaf. [2]
Blade- flat part of leaf
Petiole- stalk that attaches the leaf blade to the plant stem
Differentiate between vascular cambium and cork cambium.
Vascular cambium is the xylem and phloem in roots and stems, while cork cambium is the tough covering of the surface (bark).
Describe the process of sucrose transport in the phloem.
- Sucrose is actively transported into the cell of the phloem, which lowers the concentration of water.
- Water from the xylem moves into the phloem through osmosis, and increases the pressure in the phloem
- As the pressure increases, sucrose will move to areas of lower pressure and is passively removed from the phloem to the surrounding cells.
- When sucrose is removed, pressure drops, and water moves out of the phloem by osmosis.
Describe the structure of phloem and what it does.
- Sieve tube elements are alive at maturity and have no nucleus. Companion cells have nuclei, and perform life functions for sieve tube elements.
- Transports nutrients from leaves to the rest of plant.
What is gravitropism?
A directional change of growth in response to gravity.
Describe the internal structure of a leaf. [4]
Epidermis- covered in a waxy cuticle to prevent water loss, protect against bacteria, insects, and moulds
Stoma- pore-like opening in epidermis on bottom of leaf, protected by guard cells that control opening and closing in regards to changes in water pressure
Mesophyll cells- middle layer of cells in leaf mainly responsible for photosynthesis, made of spongy mesophyll and pallisade mesophyll
Vascular tissue- xylem and phloem transport water and minerals into leaf, and dissolved carbs out of leaf
What is meristematic tissue? Where is it found, and what are the two different types?
Meristematic tissue is undifferentiated, embryonic tissue.
It is found in rapidly dividing cells. There are apical meristems and lateral meristems.
Define tropism.
A directed change in growth or movement in response to stimulus.
What does the phloem transport?
Sucrose
Describe the structure of xylem tissue and what it functions to do.
- Tracheids and vessel elements begin as living cells, die at maturity, and leave cells walls in place
- Transports water from roots to leaves
How does temperature affect plants? [4]
- Rate of cellular respiration is affected, as most plants have an optimal temperature range.
- Opening and closing of stomata are affected
- Rate of transpiration is increased on hot, sunny days
- Temperature can signal the formation of seeds or times of flowering.
What is dermal tissue? Where is it found and what function does it serve? [5]
Dermal tissue is the outer covering of a plant, made up of epidermal cells and pairs of guard cells that surround a stoma, or small opening for gas exchange.
The guard cells control the opening size of the stoma, and root hairs on root epidermal cells increase surface area for absorption of water and nutrients.
What is the stem structure of herbaceous and woody plants, respectively?
- Herbaceous stems don’t contain wood, carry out photosynthesis, and have a thin epidermis.
- Woody stems have wood, have bark, and do not carry out photosynthesis.
Describe how water is transported in a plant.
- Water enters the root through osmosis.
- Water enters the xylem through pits in the vessels called tracheids
- Water moves up a tree against gravity in a variety of processes.
What is a hormone?
A chemical compound manufactured by specialized tissue in one part of an organism that regulates the activity of another body part or parts.
Where is apical meristem located?
At the tip of the roots and shoots of a plant.
Differentiate between primary and secondary growth in plants.
Primary growth is growth that results in an increase in length and diameter and occurs in the apical meristems, and secondary growth results in an increase in girth and occurs in lateral meristems.
How does soil affect plants? [4]
- Provides anchor support and roots with air
- Holds water and nutrients
- Needs to have a certain amount of air, water, and humus
- Most plants prefer mildly acidic soils
Describe the structure of the xylem.
Made up of tracheids and vessels that are long tubes, both dead at maturity.
Define photoperiodism.
A plant’s response to changes in day length.
Name 5 characteristics of monocots.
Monocots have one cotyledon (embryonic leaf), the veins in leaves are parallel, vascular bundles are scattered in the stem, petals and stamens appear in multiples of three, and have a fibrous root system.
What is thigmotropism?
A directional change in growth due to a response to touch.
Name the four main organs of plants.
- Leaf
- Stem
- Root
- Flower
List the four types of plant tissue.
Meristematic tissue, dermal tissue, ground tissue, and vascular tissue.
Define active transport.
The movement of a substance against a concentration gradient.
Why might the location of source and sink cells change?
Depending on the time of year or the plant’s development.
Define translocation.
The movement of minerals from one part of a plant to another.
Differentiate between hypotonic, hypertonic, and isotonic.
Hypotonic solutions have a higher concentration inside than outside, hypertonic solutions have a lower concentration inside than outside, and isotonic solutions have an equal concentration outside and inside.