Plant Reproduction Flashcards
The key features of the angiosperm life cycle are characterized by the tree F’s: —, ——, and —
- Flowers
- Double fertilization
- Fruits
Flowers are the reproductive shoots of the ——
* Attach to a part of the stem called the —
- Angiosperm Sporophyte
2. Receptacle
4 floral organs:
- — and — are sporophylls: leaves specialized for reproduction
- — and — are sterile modified leaves
- Stamen
- Carpel
- Petals
- Sepals
——: contain all 4 floral organs
Complete flowers
——: lack one or more floral organs
Incomplete flowers
—: evolution of interacting species in response to changes in each other
Coevolution
Shapes and sizes if flowers often correspond to the —transporting parts of their — pollinators
*E.g. Darwin correctly predicting a moth with a 28 cm long tongue based on the morphology of a particular flower
- Pollen
2. Animal
The angiosperm life cycle includes:
- — development
- — delivery by ——
- ——
- — development
- Gametophyte
- Sperm
- Pollen tubes
- Double fertilization
- Seed development
The ——, or female Gametophyte, develops within the megasporangium of the ovule
Embryo sac
—— surround each megasporangium, except at the —
- 2 integuments
2. Micropyle
The megasporocyte within the megasporangium undergoes meiosis, producing 4 —, only — of which survives (others degenerates)
- Megaspores
2. One
The Megaspore divides — with out cytokinesis, producing a large cells with —— nuclei
- 3x
2. Eight haploid
The large cell with eight haploid nuclei is then partitioned with membrane into a multicellular female gametophyte, the ——
Embryo sac
—— develops into the embryo
1 egg
——— help attract & guide the pollen tube
2 synergid cells
——— of unknown function
3 antipodal cells
——— are not partitioned into separated cells
* Combine with one sperm nuclei to the — nucleus of the large central cell
- 2 polar nuclei
2. Triploid
Each anther develops —— (pollen sacs) containing microsporocytes
4 microsporangia
Each micro-sporophyte produces ——— by —
- 4 haploid Microspores
2. Meiosis
Each Microspores undergoes mitosis to produce a gametophyte consisting of 2 cells: —— and ——
- This gametophyte and spore wall constitute a ——
- During maturation, the generative cells passes into the ——
- Generative cell
- Tube cell
- Pollen grain
- Tube cell
pollination is the transfer of — from an — to a —
- Pollen
- Anther
- Stigma
Pollen grain absorbs water and germinate producing a ——: delivers the sperm produced by the generative cell in the vicinity of the female gametophyte
* Tube growth directed by —— provided by ——
- Pollen tube
- chemical attractants
- Synergid cells
Sperm delivery by pollen tubes:
- As pollen tubes elongate through the —, generative cell divides producing ——
- Arrival of pollen tube initiates — of one of the synergid cells allowing passage into the ——
- Style
- 2 sperm
- Embryo sac
Double Fertilization:
- Due to — of 2 sperm into the ——
- One fertilizes the egg, the other combines with the polar nuclei, giving rise to the triploid food-storing —
- Discharge
- Embryo sac
- Endosperm
Double fertilization:
- — develops into a seed
- Ovary develops into — enclosing the —
- When a seed germinates, the embryo develops into a new —
- Ovule
- Fruit
- Seed
- Sporophyte
The process of how a seed develops into a flowering plant includes:
- — development
- — development
- Seed —
- seed —
- — development
- —
- Endosperm
- Embryo
- Dormancy
- Germination
- Seedling
- Flowering
Endosperm development usually precedes — development
- Triploid nucleus of cell divides forming ——— with milky consistency
- Subsequently, becomes — by cytokinesis and cell wall formation forming solid endosperm, or “meat”
- Embryo
- Multinucleate “super cell” endosperm
- Multicellular
Nutrients can be stored in 2 ways:
- In most Monocots and many Eudicots, the — stores nutrients that can be used by the —
- In other eudicots, the food reserves of the endopserm are exported to the — (i.e., the mature seed lacks endosperm)
- Endosperm
- Seeding
- Cotyledons
First mitotic division produces:
* ——: gives rise to the pro embryo
* ——: produces thread of cells called the —
~ Anchors to parent and helps in transferring nutrients to embryo
- Terminal cell
- Basal cell
- Suspensor
Cotyledons (primordial leaves) develop from the —
* — cotyledons for Eudicots and — for Monocots
- Pro embryo
- Two
- One
Shoot and root apexes form between cotyledons and at site of ——, respectively
Suspensor attachment
Embryo and its food supply are enclosed by a hard, protective ——
Seed coat
During last stages of maturation, the seed —
* Mature seed is only about ——% water
- Dehydrates
2. 5-15%
Enters a state of —
* Stops growing and metabolism nearly ceases
Dormancy
In some Eudicots the embryo consists of: embryonic axis attached to 2 thick — packed with — absorbed from the —
- Cotyledons
- Carbohydrates
- Endosperm
—: embryonic axis below the cotyledons; terminates in the —(embryonic root)
- Hypocotyl
2. Radicle
—: embryonic axis above the cotyledons
Epicotyl
The seeds of some other Eudicots, such as castor beans, have — cotyledons
* Absorb nutrients from endosperm when the seed —
- Thin
2. Germinates
Monocots embryo has — cotyledon
One
Grasses, such as maize and wheat, have a special cotyledon called a —
* large surface area that aids in endosperm — during germination
- Scutellum
2. Germination
2 sheathes enclose the embryo of a grass seed:
- — covers the young shoot
- — covers the young root
- Aid is soil — after germination
- Coleoptile
- Coleorhiza
- Penetration
Increases chances that germination will occur at a time and place most — to the —
- Advantageous
2. Seedling
The breaking of seed dormancy often requires environmental cues, such as:
- Substantial —
- — or — temperature
- Changes in —
- Rainfall
- Cold
- Warm
- Light
Most seeds remain viable after a year or two of —
* Some last only days; others remain viable for centuries
Dormancy
Depends on —: uptake of water due to low water potential of the dry seed
- Causes seed to — and — its coat
- Activates enzymes that digest —— for transfer of nutrients to growing parts of embryo
- Imbibition
- Expand
- Rupture
- Storage material
The —(embryonic root) emerges first. Next, the —— breaks through the soil surface
- Radicle
2. Shoot Tip
In many Eudicots, a — forms in the hypocotyl, and growth pushes the hook above ground
Hook
— causes the hook to straighten and pull the cotyledons and shoot tip up
Light
In maize and other grasses, which are —, the coleoptile pushes up through the soil. Creates a — for the shoot tip to grow though
- Monocots
2. Tunnel
—: mature ovary of a flower
- protects the — seeds
- Aids in seed — by wind or animals
- Fruit
- Enclosed
- Dispersal
A fruit may be classified as:
- —: ovary dries out at maturity
- —: ovary remains fleshy at maturity
- Dry
2. Fleshy
—: develops from a single or several fused carpels
Simple
—: develops from a single flower with multiple separate carpels
Aggregate
—: develops from a group of flowers called an inflorescence
Multiple
——: contains other floral parts in addition to ovaries
Accessory fruit
Many angiosperm species reproduce both asexually and sexually
- ——: results in a clone of genetically identical organisms
- ——: results in offspring that are genetically different from their parents
- Asexual Reproduction
2. Sexual Reproduction
—: separation of a parent plant into parts that develop into whole plants
- E.g. potato “eye” (vegetative bud)
- ——: arise from parent plant’s root system and become separate shoot systems; E.g., Aspen trees
- Fragmentation
2. Adventitious Shoots
—: Asexual production of seeds from a diploid cell
Apomixis
Advantages of asexual reproduction:
- No need for — – beneficial when sparsely distributed
- Pass on — genes instead of half – beneficial in a stable environment, but more vulnerable to local extinction if there is an environmental change
- — (vegetative fragments) generally stronger than seedlings produced by sexual reproduction
- A lot of — used in flowering and fruiting associated with sexual reproduction
- Pollinator
- All
- Progeny
- Energy
Advantages of sexual reproduction:
- —— is advantageous in unstable environments
- Seeds (almost always produced sexually) facilitate — to more distant locations
- Seed — allows suspension of growth until conditions are more favorable
- Genetic Variation
- Dispersal
- Dormancy
Some flowers can —— to ensure that every ovule will develop into a seed
Self-fertilize
However, “—“ rescues genetic diversity among offspring
Selfing
Many angiosperms have mechanisms that make it difficult or impossible for a flower to ——
Self fertilize
— species have staminate flowers (lacking carpels) and carpellate flowers (lacking stamens) on separate plants
Dioecious
Others have — and — that mature at different times it are arranged to prevent selfing
- Stamens
2. Carpels
——: a plants ability to reject its own pollen or close relatives
Self-incompatibility
Self-Incompatibility:
- —— mechanism
- Results from a biochemical block that prevents — from completing — and — egg
- — to the immune response of animals, except rejects self instead of non self
- — of self pollen is based on genes called s-genes
- Most common
- Pollen
- Development
- Fertilizing
- Analogous
- Recognition
Humans have intervened in the — and — makeup of plants for thousands of years
- Reproduction
2. Genetic
— is common in nature and has been used by breeders to introduce new genes
Hybridization
Plant biotechnology has 2 meanings:
- In a general sense: refers to — in the use of plants to make useful products
- In a specific sense: refers to use of ——— in agriculture and industry
- Innovations
2. Genetically Modified Organisms (GMOs)
— organisms: those that have been engineered to express a gene from another species
Transgenic
Genetically modified plants may increase the — and — of food worldwide
- Quality
2. Quantity
Transgenic crops have been developed that:
- Produce — to defend them against insect pests
- Tolerate — used to weed crops
- Resist specific —
- Improve — quality
- Proteins
- Herbicides
- Diseases
- Nutritional
—: fuels derived from living biomass
Biofuels
Biofuels can be produced by rapidly growing crops such as — and — that can grow on soil too poor for food production
- Switchgrass
2. Poplar
Biofuels would produce a ——— and reduce the net emission of —
- Carbon neutral cycle
2. CO2
