Chapter 38 Angiosperm Reproduction and Biotechnology Flashcards
What is plant life cycle characterized by?
Characterized by the alternation of generations:
- gametophyte (haploid)
- sporophyte (diploid)
What are the 3 Fs angiosperm life cycle is characterized by?
- flowers, double fertilization, and fruits
What is the receptacle?
- Where flowers are attached to the stem
What are the 4 floral organs?
- carpals, stamens, sepals, and petals
What are the reproductive and nonreproductive floral organs?
Reproductive: Carpels and stamens
Nonreproductive: Sepals and Petals
What does the carpel produce? What does the stamen produce?
Carpel: Produce female gametophyte (embryo sac)
Stamen: Produce male gametophyte (pollen grains)
What does the carpel contain?
- Stigma
- style
- ovary
What does the stamen contain?
- Anther
- Filament
What are complete flowers? What are incomplete flowers?
Complete flowers: Contains all 4 floral organs
Incomplete Flowers: Missing one or more floral organs
What is inflorescences?
Clusters of flowers
What are the 4 general trends in the evolution of flowers?
- Bilateral symmetry
- Reduction in the number of floral parts
- Fusion of floral parts
- Location of ovaries inside receptacles
What is included in the angiosperm life cycle? 4 things
- gametophyte development
- pollination
- double fertilization
- seed development
What is the embryo sac?
Female gametophyte that develops within the sac
What does the pollen grain consist of?
two celled male gametophyte and the spore wall
What is pollination?
The transfer of pollen from an anther to a stigma
What is a pollen tube?
A tube that grows down into the ovary and discharges two sperm cells near the embryo sac
What is fertilization?
The fusion of gametes
What happens during double fertilization?
One sperm fertilizes the egg and the other sperm combines with 2 polar nuclei to give the triploid food storing endosperm
What are the methods of pollination?
- wind
- water
- animal
What is coevolution?
specific adaptations in flowers to attract specific pollinators
What are the 6 stages of the development of a seed?
- Endosperm development
- Embryo development
- Seed dormancy
- Seed germination
- Seedling development
- Flowering
What is a seed coat?
Hard, protective layer that encloses the embryo and its food supply
What is the hypocotyl?
The embryonic axis below of the cotyledons
What is the radicle?
The embryonic root
What is the epicotyl?
Above the cotyledons
What covers the young shoot? What covers the young root?
Coleoptile: Covers young shoot
Coleorhiza: Covers young root
What is a fruit?
A mature ovary of a flower
What is a simple fruit developed from?
Developed from a single or several fused carpels
What are aggregate fruits developed from?
From a single flower with multiple separate carpels
What are multiple fruits developed from?
Developed from a group of flowers called inflorescence
What is an accessory fruit?
A fruit that contains other floral parts in addition to ovaries.
What is asexual reproduction?
Reproduction that results in a clone of genetically identical organisms
What is fragmentation?
A form of asexual reproduction in which the separation of a parent plant into parts that develop into whole plants
What is apomixis?
Asexual production of seeds from a diploid cell
What is vegetative reproduction?
Another word for asexual reproduction due to progeny arising from mature vegetative fragments
What is special about dioecious species?
These plants have their staminate and carpellate flowers on separate plants to prevent self-fertilization.
What is self-incompatibility?
A plant’s ability to reject its own pollen
What are totipotent cells?
Cells that can divide and asexually generate a clone of the original organism
What is vegetative propagation
Vegetative reproduction that is facilitated by humans
What is callus?
Mass of dividing, undifferentiated totipotent cells formed where a stem is cut and produce adventitious roots
What provides the root system? What is grafted onto the stock?
Stock provide root system
Scion is grafted onto the stock
What is the general sense of plant biotechnology? What is the specific sense of plant biotechnology?
General: Refers to innovations in the use of plants to make useful products
Specific: Refers to use of GM organisms in agriculture and industry
What are transgenic organisms?
Organisms that have been engineered to express a gene from another species
What are biofuels? What is biomass?
Biofuels: Fuels derived from living biomass
Biomass: Total mass of organic matter in a group of organisms
What are the concerns over GMOs?
- Genetic engineering may transfer allergens from a gene source to a plant used for food
- Unforeseen effects on nontarget organisms
- The possibility of introduced genes escaping into related weeds through crop-to-weed hybridization –> results in superweeds
What efforts are being used to prevent the GMO concerns?
- Male sterility
- Apomixis
- Transgenes into chloroplast DNA (not transferred by pollen)
- Strict self-pollination
Benefits of GMOs?
- Could potentially increase the quality and quantity of food worldwide
- Some transgenic crops have been developed to produce a Bt toxin, which is toxic to insect pests
- Other crops are able to tolerate herbicides or resist specific diseases
What are the steps of seed development?
- Ovule develops into seed
- Ovary develops into fruit covering seed
- Seed germinates and embryo becomes new sporophyte
What happens during embryo development?
Mitotic division splits fertilized egg into basal cell and terminal cell
What does the basal cell produce?
Produces a multicellular suspensor that anchors the embryo to the parent plant
What does the terminal cell produce?
Produces most of the embryo
What does seed dormancy do?
Increases the chances that germination will occur at a time and place most advantageous to the seedling
What is imbition?
Uptake of water due to low water potential of the dry seed; germination depends on this
