1.Plant Cells and Tissues Flashcards
2.11 Draw a typical plant cell and label the key parts
2.12a Describe the structure and the function of the ‘cell wall’
- Holds the cell contents - physical container
- It is a thick, rigid structure made from cellulose and sometimes contains lignin.
- Elastic when young to enable growth
- Rigid when mature
- Allows particles dissolved in water to travel through but prevents larger items such as fungal spores
2.12b Describe the structure and state the function of the ‘cell membrane’
- Located on the inner surface of the cell wall
- Helps to contain cell contents
- It is a semi permeable barrier, controlling the movement of certain substances in and out of the cell (when dissolved in water)
- Aids osmosis
2.12c Describe the structure and state the function of the ‘nucleus’
- Controls the plants genetic information, DNA on chromosomes
- Coordinates activities of the cell.
- It controls cell growth and cell division
- Through RNA production transmits instruction for the making or breaking down of chemicals within the cell
- Chromosomes aid with cell division and growth
DNA contained within the nucleus/ RNA can move outside the nucleus
2.12d Describe the structure and state the function of the ‘vacuole’
- Large space, within the center of the cell that contains liquid.
- Helps to maintain ‘turgidity’ within the plant
- If plant loses water the plant wilts
- Acts as storage for compounds/solutions
2.12e Describe the structure and state the function of the ‘cytoplasm’
- Enables substances dissolved within it to move around the cell components
- Has a jelly-like appearance
- Also contains the organelles and holds them in position.
2.12f Describe the structure and state the function of the ‘chloroplast’
- Small body in plant cells containing chlorophyll (the green pigment in plant cells that makes photosynthesis possible)
- Where plants convert sunlight into chemical energy that can be used by the plant
2.12g Describe the structure and state the function of the ‘mitochondrion’
- Small and plentiful organelles
- Chemical reactions take place
- Release energy in a controlled way, via respiration
2.13 Describe where cell division is located within the plant
1) apical meristems are the sites of primary lengthwise growth located at the tips of shoots and roots.
2) Lateral meristems are found in the cambium layer immediately below the bark in woody plants which allow stems and roots to increase in girth, known as secondary growth
2.21 State what is meant by the term ‘plant tissue’
Plant tissue is a group of cells, of the same type, having a common function
2.22a Describe the characteristics and function of ‘epidermis’
- A single layer of cells which form a boundary between the plant and the external environment
- Often covered by waxy layer called the cuticle
- Protects the plant against water loss
- Regulates gas exchange
- Prevents damage / attack
2.22b Describe the characteristics and function of ‘cambium’
- A layer of growing tissue that produces new cells
- Meristematic tissue where new cells are produced by cell division resulting in more xylem and phloem tissues thereby increasing the girth of the stem or root in woody plants, known as secondary growth.
2.22c Describe the characteristics and function of ‘phloem’
- Long tube like cells
- Two way flow up and down - mostly down, from leaves to roots
- Living tissue - has to actively manage the solution within it
- Soft cell wall
- Allow the transport of food and plant hormones from the leaves to the rest of the plant
2.22d Describe the characteristics and function of ‘xylem’
- Woody element of the vascular bundle
- Only have upwards flow
- Generally not living tissue - die soon after formation
- Xylem support the transport of water, nutrients & plant hormones from the roots to the rest of the plant.
- Xylem tissue also provides physical support - walls are made of lignin and are rigid
2.22d Describe the characteristics and function of ‘parenchyma’
- Thin walled general-purpose plant cells
- Make up the bulk of plant
- Plentiful often playing a ‘packing’ function bulking out the volume of a plant. They can also provide functions such as:
- Photosynthesis
- Water storage
- Aeration - facilitate gas exchange
- Food storage - in form of starch
- Protection - help to prevent damage to the plant
