I. Types of plant reproduction A. Asexual reproduction

advertisement
I. Types of plant reproduction
 
A. Asexual reproduction - mitosis; "cuttings"
 
1. does not require the production of sex cells
 
2. one organism produces offspring genetically identical to itself
 
3. used by growers to start new plants quickly
B. Sexual reproduction
 
1. requires production of sex cells
 
a. sperm = pollen
 
b. eggs = in cones or flowers depending on plant
 
2. offspring are genetically different from either parent
 
3. fertilization - combination of egg and sperm to produce a zygote
 a. method of fertilization
 
1. water and wind pollination help fertilization
 
2. animals help fertilization as pollinators
 
4. reproductive organs
 
a. can be on the same plant or on separate plants
II. Plant Life Cycles - two stages
 
A. gametophyte stage
 
1. meiosis
 
2. produces haploid cells
3. spores divide by cell division to form plant structures or new plant  
 
4. some of these cells form sex cells
 
B. sporophyte stage
 
1. fertilization
 
2. diploid cells
 
3. some cells will undergo meiosis to start cycle again
II. Advantages of asexual reproduction
 
A. usually faster than sexual reproduction
 
B. only one plant needed - no “mate”  necessary
 
C. in a stable environment, lack of genetic variation may be advantageous
III. Disadvantages of asexual reproduction
 
A. provides no genetic diversity
 
1. decrease chances of survival in environmental changes
Moss Life Cycle
Download