General Flashcards
What unique feature do rhodophytes have?
Non-flagellated sperm
List the unique features that charophytes and embryophytes share
- Rosette shaped complexes for cellulose synthesis
- Peroxisome like enzymes to reduce to loss from photo
- Structure of flagellated sperm
- Phragmoplast
What is the structure of the sperm in embryophytes?
9+2 arrangement
What is the function of the phragmoplast?
To guide the golgi apparatus during cell plate formation before cytokinesis
What would happen to the cell without the phragmoplast?
It wouldn’t be able to divide
Derived traits of plants(embryophytes)
- Cuticle to prevent desiccation
- Mutualistic relationships with fungi
- Multicellular embryos
- Generation alternation
- Multicellular gametangia
- Possession of apical meristems
- Production of walled spores in the sporangia
Explain the process of alternation of generations.
Diploid sporocyte undergoes meiosis to produce haploid spores. Spores undergo mitosis to create haploid gametocytes. Gametes undergo syngamy to form diploid zygotes.
What do spores contain that prevents desiccation?
Sporopollenin
What is the female gametangia called?
Archegonia
What is the male gametangia called?
Antheridia
What are the types of apical meristems?
Root, shoot, axillary bud, and intercallary
What is the function of apical meristems?
Primary growth - growth in length
What is the function of the cell wall?
Provides tensile strength against osmotic and mechanical stress. Creates turgor pressure.
What does the cell wall contain?
Cellulose microfibrils, hemicellulose, pectin, lignin, soluble protein
How are cellulose microfibrils synthesized?
Inside out in the plasma membrane
What would happen without microtubules?
The cell wall wouldn’t form, it would be disorganized, or it would lose its structure
What is the purpose of the secondary cell wall?
Provides structure
What are pectins?
Heterogenous group of polysaccharides
Where are pectins found?
Primary cell wall and middle lamella
What is the middle lamella?
Extracellular space between primary and secondary cell wall
How is pectin made?
Synthesized by Golgi apparatus
What is the function of pectins and how do they work?
Forms a gel in the matrix by linking with calcium ions to assist in cell adhesion and wall hydration
When does the secondary cell wall form?
After expansion ceases. After mature cells undergo apoptosis
What is the function of the secondary cell wall?
Adds mechanical strength
List some features of the secondary cell wall
Higher proportion of cellulose. Microfibrils are more parallel-oriented. Often impregnated with lignin.
How are the microfibrils in the primary cell wall oriented?
Transversely/radially
True or false: Growing plants increase in girth and length
False, only in length
What determines the orientation of newly deposited microfibrils?
Cortical microtubules
How does water affect the amount that the plant grows?
As the plant expands, it is not gaining/growing any new/more organelles. The influx of water determines how much it grows before reaching maturity
Where are cellulose microfibrils synthesized?
Plasma membrane
What is the evolutionary advantage of walled spores?
Prevents erosion + protects spore
