Exam 2 Flashcards
What is dormancy?
The seed will germinate when environmental conditions are right
What is the quiescent phase?
A resting phase followed by germination
What happens during seed maturation?
Food stores build up, the seed dessicates, and the seed coat hardens
What are meristems?
Growth tissue
What are the three tissue types?
Vascular tissue, dermal tissue, and ground tissue
What is the apical-basal pattern of growth?
Upwards and downward growth. Apical is up, basal is down?
What are the two patterns of plant growth?
Apical-basal and radial
What is embryogenesis?
Formation of the embryo
What are gymnosperms?
Vascular plants with seeds but no fruit or flowers
What are eudicots?
Plants with two cotyledons
What are monocots?
Plants with a single cotyledon
What are the types of angiosperm?
Monocots and eudicots
What are angiosperms?
Vascular plants with flowers, seeds, and fruit
What are the two types of vascular plants?
Angiosperms and gymnosperms
Define vascular.
Networks of cells that move water and sugars throughout the plant
What is step 3 of speciation?
Reinforcement in the form of secondary contact. The populations return to sympatry and any hybrid offspring have reduced fitness
What is step 2 of speciation?
Divergence. The populations must diverge genetically
What is allopatric speciation?
Geographic isolation
What is step 1 of speciation?
Isolation of populations
Where does primary growth occur?
Tips of roots and shoots (apical & basal meristems)
What is after-ripening dormancy?
Requires environmental changes (ex: vernalization)
What is embryo dormancy?
Hormone ratios prevent germination
What is coat-imposed dormancy?
When the seed coat prevents water and oxygen from entering the seed.
What is a point mutation?
A change in a single base pair.
What is a population bottleneck?
When a population crash occurs and the survivors become the founders of a new population.
What is the founder effect?
When a small number of individuals leave a larger population and start a new population, the allele frequencies are likely to be different
What is disruptive selection?
Heterozygote is less fit than homozygote
What is balancing selection?
The heterozygote is more fit than either homozygote, maintaining both alleles in the population
What is directional selection?
One allele is favored over other alleles. The favored allele will be driven to fixation while the others will be driven to loss.
Name the 4 postulates of evolution through natural selection.
- Individuals within a population show variation within a trait.
- Some of the variation is inherited by offspring.
- Individuals have different reproductive and survival success.
- Survival and reproduction are not random with respect to the trait.
Define migration.
Changes in allele frequency within different populations of the same species due to migration.
Define mutation
Creates new alleles
Define genetic drift
Random chance movement of allele frequencies
Define selection
External agent applies selective pressure that influences which genes are passed on to the next generation
Name the four mechanisms of evolution.
Migration, mutation, genetic drift, and selection.
Define microevolution.
Small-scale changes within populations over time.
What is hybridization?
When separate species can produce viable offspring.
What is interbreeding?
Producing fertile offspring.
What is the biological species concept?
A group of potentially interbreeding organisms that are reproductively isolated from all such other groups.
What is the phylogenic species concept?
Evolutionary history based on unique character states. Organism must be related to other members of a species.
What is the morphospecies concept?
Distinct morphological differences define species; based on appearance and other comparable traits.
How do we recognize a species?
Biological species concept, phylogenic species concept, and morphospecies concept.
What is an adaptation?
A trait that evolves by natural selection for a particular function that increases fitness.
What is gene flow?
The transfer of alleles from the gene pool of one population to the gene pool of another.
How does polyploidy occur?
Mutation causes production of diploid gametes, then tetraploid offspring create diploid gametes.
List some causes of dormancy.
Coat-imposed dormancy, embryo dormancy, and after-ripening
What is a dominant allele?
An allele that is expressed whenever it is part of the genotype.
Define phenotype.
The physical manifestation of a genotype in a particular environment.
Define genotype.
The genetic makeup of an individual at one or more genes.
Define heterozygous.
Individual with different alleles on each chromosome.
Define homozygous.
An individual with the same allele on both chromosomes.
What is an allele?
One of the alternative forms of a single gene at a single locus.
What is a locus?
The position the gene occupies on a chromosome.
What is a gene?
A sequence of DNA that codes for a specific protein or RNA
Define meiosis.
The process by which a diploid cell becomes four haploid cells.
Define asexual reproduction.
The process by which a single individual produces viable offspring.
Define sexual reproduction.
The process by which two individuals contribute genetic material to viable offspring.
What is the third stage of the Calvin Cycle?
Some of the PGAL comes back as RuBP and is cycled through the Calvin Cycle again.
What is the second stage of the Calvin Cycle?
PGA is reduced to PGAL
What is the first stage of the Calvin Cycle?
CO2 fixed to RuBP is hydrolyzed to form 2 PGA molecules.