3 Botanical & Anatomical Basis of Plants Flashcards
Genome =
Set of chromosomes (genes and other DNA) within the gametes of a species
True or false: In plants, most DNA is in nucleus in linear chromosomes
and some DNA also occurs in the chloroplasts & mitochondria
True
Name the two types of cells in a sexually reproducing plant
Somatic cells and gametes cells
Like humans, plants undergo biparental inheritance , which is:
Half of nuclear DNA from father (pollen grain) & half from mother (egg)
Mitosis occurs only in ____ cells, where daughter cells contains same # of chromosomes as mother cell
Undifferentiated cells used to introduce foreign DNA
Can be disrupted using a chemical____ that interferes with spindle fiber formation
Method used to change number of chromosomes
- somatic
* colchicine
Why cytokinesis cannot proceed in plants?
Because plant cells have walls. Instead, during telophase, a cell plate forms across the cell in the location of the old metaphase plate
______ allows genetic exchange between non-sister chromatids and occurs only in ____
Crossing over
Meiosis
Examples of natural autoploids (duplications of the same exact genome):
Examples of natural alloploids (combination of different genomes):
*Banana (triploid) = Seedless
Tetraploid crops, such as alfalfa, peanut, potato & coffee
Horticulture polyploid varieties selected for larger flowers
*wheat, oat, tobacco, cotton, sugarcane, strawberry & blueberry
Effects of polyploidy
Increased cell size Increased organ size Slower growth rates Flower later and over a longer period of time Altered chemical composition
- Vitamin A content is tetraploid corn is 40% greater than in diploid corn
- Vitamin C known to increase in vegetables and fruit after chromosome doubling
Autopolyploids generally have fertility problems and reduced pollen production
Basic plant anatomy
Root & shoot system (dibujos en la slide 15)
True or false:
unisexuals have both male and female sexual organs and are thus capable of self-fertilization
hermaphrodites have only one type of reproductive organ and must cross-fertilize
False
Hermaphrodites have both male and female sexual organs and are thus capable of self-fertilization
Unisexuals have only one type of reproductive organ and must cross-fertilize
True or false
Autogamous cross = pollen comes from same flower
Allogamous cross = pollen comes from different flower
True
What is self-incompatibility?
occurs when some species reject pollen from their own flowers, promoting out-crossing
Asexual species reproduce by:
*Vegetative reproduction (no seed is produced)
New parts grown from the same plant (genetically identical)
*Agamospermy (seed is produced from unfertilized ovules) , Offspring are genetically identical to parent
Asexual reproduction produces plants with genetic variation true or false
False
Methods such as ______are used for propagating tree crops
grafting and budding
What is apomixis?
Developing seeds without fertilization, asexual production of seed with no opportunity for genetic recombination
Rare event in nature: that is used to maintain original genetic properties indefinitely and reduces cost of maintenance (no need to maintain parental genotypes)
Beneficial when uniformity of product is desired
Basic 2 growth phases :
Vegetative: Non-sexual parts are formed
Stem, branches, leaves, etc…
Reproductive: Flowers are produced
What is alteration of generations?
Plants that undergo throug Gametophyte generation
(Begins with haploid spore produced by meiosis
Cells produced from this gametophyte by mitosis are haploid)
and Sporophyte generation
(Starts once the sexual reproductive process unites gametes to form a zygote)
True or false
Perennials are plants with the ability to repeat their life cycle without dying
True
Stamen = ___ reproductive parts
Stalk (___) is attached to pollen-containing chambers that are fused together (___)
Stamens are collectively called the ____
Male
filament
anther
androecium
Pistil = ____reproductive parts (center)
Stigma accepts the pollen
___ is the tube leading to the ovary
Stigma, style and ovaries together are called ___and one or more carpels make up the ___
Female
style
carpels
gynoecium
\_\_\_ = Leaf-like structures that enclose the flower before its ready for fertilization \_\_\_= Showiest/colorful part of the flower, to attract pollinators
sepal
petals
Process of forming gametes, produced from specialized diploid cells:
Microspore mother cells, located in ____
pollen grains produced , 2 nuclei each
Megaspore mother cells, located in _____
(8 nuclei) one of which eventually will become the egg
Gametogenesis
- anthers
- ovaries