Reproduction Flashcards
Asexual Reproduction
Reproduction in which a single parent produces an offspring by cell division –> genetic makeup of offspring is identical to plant (doesn’t involve fusion of male and female gametes)
Structures Involved in Asexual Reproduction
Rhizomes and corms (underground stems), stolons, “eyes” on tubers, suckers (shoots that grow from plant’s roots), growth fragments of roots or shoots
Advantages of Asexual Reproduction
- All offspring could get a trait that helps them survive in a specific environment
- Less energy required –> individuals produced more quickly
- Only one plant needed
- Plantlets are more robust and have higher survival rates
Disadvantage of Asexual Reproduction
Lack of variation makes individuals susceptible to disease and damage/loss of life due to environmental changes
Human Uses of Asexual Reproduction
Stem Cutting: stem is cut and placed in water - once roots form, placed in soil
Grafting: young branch from one plant attached to stem and root of another plant (often used with apple trees)
Sexual Reproduction - why seeds?
Seeds protect and nourishes the enclosed embryo and helps it transport to a new location (by animals, wind, fire, etc.)
Advantages of Sexual Reproduction
- High level of genetic diversity –> helps survival if environment changes
- Seedlings can be dispersed away from plant –> less competition
- Seeds can remain dormant for long time and germinate when conditions are favourable
Disadvantage of Sexual Reproduction
Plant must devote a lot of resources to sexual reproduction
Sexual Reproduction in Gymnosperms
Pollen grains must travel from male cone and land close to ovule of female cone - takes place through wind
Sexual Reproduction in Angiosperms
Anther releases pollen which is carried to stigma by wind or animals either through cross pollination (between plants) or self-pollination (same plant) –> some plants only have male parts, some one female, some both
