Folk plant bio test 3

allele

Different forms of a gene

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait

Dominant

Describes a trait that covers over, or dominates, another form of that trait.

recessive

An allele that is masked when a dominant allele is present

incomplete dominance

Situation in which one allele is not completely dominant over another allele. phenotype is mixed between the 2.

Phenotype

An organism's physical appearance, or visible traits.

independent assortment

Independent segregation of genes during the formation of gametes

linkage

occurs when different traits are inherited together more often than they would have been by chance along; it is assumed that these traits are linked on the same chromosome

epistasis

A type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited.

polygenic trait

trait controlled by two or more genes

Pleiotropy

The ability of a single gene to have multiple effects.

expression of genes

the translation of a gene's encoded information into the production of proteins, determining the gene's functioning

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

Translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

transcription factors

Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.

Heterochromatin

Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed.

DNA methylation

The addition of methyl groups to bases of DNA after DNA synthesis; may serve as a long-term control of gene expression. Cytosine specifically.

RNA interference

Blocking gene expression by means of an miRNA silencing complex. After RNA is already made. Binds to an already made mRNA to deny access from tRNAs

Mutation

A change in a gene or chromosome.

point mutation

a mutation affecting only one or very few nucleotides in a gene sequence.

speciation

the formation of new and distinct species in the course of evolution.

Inversion (DNA)

Mutation where a segment of chromosome is reversed, because of a breakage and then rearrangement

Translocation

Change to a chromosome in which a fragment of one chromosome attaches to a nonhomologous chromosome.

Aneuploidy

Abnormal number of chromosomes.

Polyploidy

A chromosomal alteration in which the organism possesses more than two complete chromosome sets. more tolerated in plants than animals.

gene pool

Combined genetic information of all the members of a particular population

Hybridization

genetic flow between species.

gene flow

movement of alleles from one population to another

genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection. no consistent directionality

bottleneck effect

A change in allele frequency following a dramatic reduction in the size of a population.

fitness

how well an organism can survive and reproduce in its environment

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

rapid adaptation

rapid changes in natural selection. Controversial because rapid climate change results more in extinction than adaptation.

ecotype

a population adapted to its unique local environmental conditions

Coevolution

Process by which two species evolve in response to changes in each other.

allopatric speciation

The formation of new species in populations that are geographically isolated from one another.

sympatric speciation

The formation of new species in populations that live in the same geographic area

polyploidy

condition in which an organism has extra sets of chromosomes

allopolyploidy

polyploidy resulting from contribution of chromosomes from two or more species

Autopolyploidy

an individual that has more than two chromosome sets that are all derived from a single species

recombination

the genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division

asexual reproduction advantages

less energy and time, one parent, favourable conditions

asexual reproduction disadvantages

no genetic variation

selfing

self-fertilization

outcrossing

gametes from different individuals combine to form offspring

cleistogamous

Applied to flowers or florets fertilized without opening; must be self-fertile

Macroevolution

large-scale evolutionary changes that take place over long periods of time

microevolution

Change in allele frequencies in a population over generations.

asexual reproduction mechanisms

Rhizomes, bulbs, stolon, tubers, bulbils and root sprouts

stolon

a horizontal branch from the base of plant that produces new plants from buds at its tips

bulbil

a small bulblike structure, especially in the axil of a leaf or at the base of a stem, that may form a new plant.

root sprouts

May sprout new plants from their root system in a form of reproduction. Ex Poplar trees are known for making unwanted.. Ex Century Plant at the beach

rhizome

a horizontal, underground stem that produces new leaves, shoots, and roots

tuber

a swollen underground stem

bulbs

the round parts of some plants that are underground

inbreeding depression

when individuals with similar genotypes - typically relatives - breed with each other and produce offspring that have an impaired ability to survive and reproduce

Plant Science

the science of plant growth, care and management

botany

study of plants

Systematics

study of the diversity of life and the evolutionary relationships between organisms

Phylogeny

The evolutionary history of a species or group of related species

Taxonomy

The scientific study of how living things are classified

predictive framework

A phylogeny is \______.

Taxonomic "dark matter"

most life on earth has yet to be described. New organisms are discovered every year.

taxa

group or level of organization into which organisms are classified

phylogenetic tree

A family tree that shows the evolutionary relationships thought to exist among groups of organisms

monophyletic taxon

contains all the descendants of a particular ancestor

paraphyletic

Pertaining to a group of taxa that consists of a common ancestor and some, but not all, of its descendants.

polyphyletic

pertaining to a group of taxa that includes distantly related organisms but does not include their most recent common ancestor

Synapomorphy

shared derived character

Symplesiomorphy

shared ancestral trait

taxon

group or level of organization into which organisms are classified

outgroup

species/sample outside group of interest

Homoplasy

A similar (analogous) structure or molecular sequence that has evolved independently in two species.

homology

similarity resulting from common ancestry

OTU

-operational taxonomic unit
-similar to phylotypes

sister taxa

Groups of organisms that share an immediate common ancestor and hence are each other's closest relatives. closest to each other on the phylogenetic tree.

dominant sporophyte

the life cycles of vascular plants are dominated by a diploid sporophyte that is much larger than the gametophyte

branched sporophyte

can make more spores and disperse them over a wider area (evolved before vascular plants)

Lignification

Increased thickness and toughness of plant walls when lignin is deposited within the original cell wall

Schlerenchyma

Provides structural support, contains a large amount of lignin, cells are often dead at maturity

true roots

have vascular tissues gathered in a central area of the root that is called the vascular cylinder

alternation of generations

the alternation between the haploid gametophyte and the diploid sporophyte in a plant's life cycle

Pteridophytes

Seedless plants with true roots with lignified vascular tissue. The group includes ferns, whisk ferns, and horsetails.

gametophyte

The stage in the life cycle of a plant in which the plant produces gametes, or sex cells.

Is pollen haploid or diploid?

haploid

lycophylls

tiny leaves on lycophytes with a single unbranched vein

enation

an outgrowth from the surface of a leaf or other part of a plant.

Lycopodiophyta

club mosses

Euphyllophytes

The group of vascular plants that is sister to the lycophytes and which includes all plants with megaphylls.

true leaves

-branched veins
-True Ferns onwards

Monilophytes

ferns, horsetails, whisk ferns

Equisetopsida

Class of plants that made up a major part of the vegetation of the Carboniferous Period, that consist of a single stem, terminated by a strobilus

strobilus

compact cluster of spore-bearing structures in some seedless vascular plant sporophytes

Leptosporangiate ferns

Sporangia walls only one cell thick
Most are terrestrial; a few aquatic species
Require liquid water for movement of sperm, so most inhabit moist woodlands and swamps

Polypodiopsida

Class of ferns with large, spirally arranged, compound leaves with sporangia grouped in sori on their undermargins

circinate vernation

As in ferns, the coiled arrangement of leaves and leaflets in the bud; such an arrangement uncoils gradually as the leaf develops further.

sori

raised spots located on the underside of sporophyte ferns, clusters of sporangia

sporangia

multicellular organs that produce spores

Azolla

Aquatic fern that has symbiotic blue green bacterium, important in rice paddies. Has nitrogen fixing bacteria, no nodules