Lab Quiz Flashcards
Founder Effect
When a few individuals from an original population disperse and inhabit (“found”) a new area. The genetics of these few individuals will be passed on to all the offspring in the newly inhabited area; thus the genetic diversity of this population will be less comprehensive compared to the original population
Bottleneck Effect
When a population is greatly reduced but then recovers. Relatively few individuals survive the bottleneck, so they pass their less-comprehensive genetic diversity onto the rest of the growing population.
Microevolution
A change in allele/gene frequency in a population. Can happen due to mutation, natural selection, gene flow, and genetic drift.
Genetic Drift
A change in allele frequencies due to chance. Genetic drift occurs in every population and every generation, but affects smaller populations more significantly.
Genotype
The genetic constitution of an organism. The total sum of genes transferred from parent to offspring. The complete set of heritable genes that can be transferred to the offspring from its parents
Allele
Alternate forms of the same gene; different alleles may code for different phenotypes
Phenotype
Set of observable characteristics or traits of an organism that results from the interaction of its genotype with its environment.
Monophyletic
A genetic group that includes all the descendants of an ancestor that can include any number or organisms or groups. Synonym for clade.
Paraphyletic
A group that contains a common ancestor, but not all of its descendants
Homology
Similar structures between two organisms resulting from common ancestry
Eukaryotic organelle characteristics
Have mitochondria, chloroplasts, Golgi apparatus, endoplasmic reticulum, ribosomes (much larger than prokaryotes’), etc.
Prokaryotic organelle characteristics
Only have ribosomes
Eukaryotic nucleus characteristics
Has a true nucleus surrounded by a nuclear membrane
Prokaryotic nucleus characteristics
Has no true nucleus, but has a nucleoid, or nuclear region
Eukaryotic organization of DNA characteristics
DNA is packaged in more than 1 linear chromosome with histones and other proteins. Have much more DNA than prokaryotes
Prokaryotic organization of DNA characteristics
Has 1 usually circular chromosome and few proteins
Eukaryotic type of cell division
Mitosis
Prokaryotic type of cell division
Binary fission
Eukaryotic size
Large
Prokaryotic size
Very small
Modified leaves
Flowers are modified leaves
Sepals, petals, stamen, and pistils are whorls of modified leaves at a single node
Rosette
Stem modification
A short, upright shoot with very short internodes so leaves appear almost whorled at the ground level. Leaves protect stem from animals and weather and the tight arrangement makes it difficult to uproot the plant
Examples: dandelion and lettuce
Rhizome
Stem modification
A horizontal stem that may be under or partly in the ground and may bear leaves on its upper surface and roots on its lower surface. Stores starches, proteins, and other nutrients
Example: iris
Stolon/Runner
Stem modification
A stem that grows horizontally over the ground and may produce new plants at the nodes. Allows plant to propagate nearby areas
Example: strawberry
Bulb
Stem and leaf modification
Shoot with short stem and thick fleshy leaves. Outermost leaves are thin, dry, and protective. Specialized for nutrition and energy storage
Example: onion, tulip, hyacinth
Corm
Stem modification
A thickened, usually underground and upright stem that accumulates food such as starch. It stores food in the stem (a bulb stores primarily in the leaves). May see encircling rings that are leaf scars of detached leaves
Examples: gladiolus, crocus
Tuber
Stem modification
An enlarged, short, fleshy, underground stem that often develops from the tip of the rhizome and is utilized for food storage and propagation
Example: Irish potato
Stem Tendril
Stem modification
A slender, coiling structure that provides support. Generally in the axil of a leaf or leaf scar. If a tendril originates from an axillary bud, it is a stem tendril.
Examples: grape, Virginia creeper
Thorn
Stem modification
Hard, woody, pointed branch that may bear small leaves and provides protection from herbivores. Thorns typically found in the axil of a leaf or leaf scar.
Examples: honey locust, hawthorn
Cladophyll/Cladode
Stem modification
A branch that resembles a leaf and may bear flowers, fruit, and/or small leaves. Generally found in the axis of a leaf, which may be small and scale-like or may have fallen off.
Example: butcher’s broom
Stem succulence
Stem modification
Thick, fleshy stem specialized for water storage.
Example: cactus
Sepals and petals
Leaf modification
Sterile parts of the flower
Pistil
Leaf modification
Reproductive part of the flower. Female part consists of ovary, style, and stigma
Stamen
Leaf modification
Reproductive part of the flower. Male part composed of filament and anther. Anther is at the top and produces pollen
Leaf tendril
Leaf modification
Coiled structure that attaches a plant for support. Generally has a bud in its axil or will be a modified leaflet of a compound leaf
Example: pea
Spine
Leaf modification
A hard, sharp-pointed structure offering protection from herbivores. A spine will have a bud, leaf, or leaf scar in its axil. In some cases spines take he place of leaves
Example: cactus
Bract
Leaf modification
A leaf that may be reduced or substantially different from the others on a stem and is usually found just below a flower. It provides additional color to attract pollinators.
Example: the colored, floral bracts of poinsettias
Stipule
Leaf modification
Often blade-like appendage at the base of the leaf blade or leaf petiole. Function is unknown, and many are hypothesized to be useless
Example: pea
Leaf succulence
Leaf modification
A fleshy leaf specialized for water storage
Example: crassula
Insectivorous leaves
Leaf modification
Leaves specified for trapping and ingesting insects and other small invertebrates. Ingested insects usually provide a source of nitrogen.
Example: pitcher plant, venus fly trap, sundew, and butterwort
What are endophytes?
Microorganisms that live inside plants for at least part of their life cycle without causing obvious signs of disease. Endophytes can be bacteria or fungi and often co-evolve with their hosts.
Why are endophytes important?
Possess immense biochemical diversity and are known to produce antibiotics, antiviral compounds, antioxidants, insecticides, and other molecules that are beneficial to the host plant or and/or that may be helpful in human medicine, agriculture, and industry. Many endophytes produce enzymes that have potential applications in industry and medicine.
What is the ecological function of endophytes?
They produce a wide range of compounds useful for plants for their growth, protection to environmental conditions, and sustainability.
