Lecture Notes Review - Vocabulary Flashcards

Genetics

• Chromosome: Structure of nucleic acids and protein carrying genetic information in the form of genes. For example, humans have 46 chromosomes arranged in 23 pairs.
• Gene: A unit of heredity that is transferred from a parent to offspring and determines some characteristic of the offspring. For instance, a gene might determine the color of a flower.
• Allele: One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome. An example is the alleles for eye color, such as brown or blue.
• Homologous: Chromosomes having the same genes in the same order. These pairs line up during meiosis.
• Chromatid: One of two identical halves of a replicated chromosome. Sister chromatids are formed during DNA replication.
• Reduction: Refers to reduction division in meiosis where the chromosome number is halved from diploid to haploid. This ensures that offspring have the correct number of chromosomes.
• Recombination: The rearrangement of genetic material, especially by crossing over in chromosomes or by the artificial joining of segments of DNA. Recombination leads to genetic diversity.
• Genotype: The genetic constitution of an individual organism. For example, BB or Bb for a particular trait.
• Phenotype: The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment. For instance, having blue eyes.
• Recessive: An allele that produces its characteristic phenotype only when its paired allele is identical. An example is the allele for blue eyes (bb).
• Dominant: An allele that produces the same phenotype whether the paired allele is identical or different. An example is the allele for brown eyes (BB or Bb).
• Punnett Square: A diagram used to predict the genotypes and phenotypes of offspring in a genetic cross. It helps visualize possible combinations of alleles.
• Sex-linked: A gene located on a sex chromosome. An example is hemophilia, which is linked to the X chromosome.
• Codominant: A relationship between two versions of a gene. Both alleles are expressed and contribute to the phenotype of the individual. For example, in blood types, A and B alleles are codominant.
• Incomplete Dominance: A genetic situation in which one allele does not completely dominate another allele, and therefore results in a new phenotype. For instance, red and white flowers producing pink flowers.
• Test Cross: A genetic cross between a homozygous recessive individual and a corresponding suspected heterozygote to determine the genotype of the latter. This helps determine if an organism is heterozygous or homozygous dominant.
• Zygote: A diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum. This is the first cell of a new organism.
• Haploid: Having a single set of unpaired chromosomes. For example, sperm and egg cells.
• Diploid: Containing two complete sets of chromosomes, one from each parent. Most somatic cells are diploid.

Evolution

• Evolution: Change in the heritable characteristics of biological populations over successive generations. This change can lead to new species.
• Natural Selection: The process whereby organisms better adapted to their environment tend to survive and produce more offspring. For example, peppered moths evolving darker coloration during the industrial revolution.
• Adaptation: The process of adjustment to actual or expected climate and its effects. An example is the development of drought-resistant traits in plants.
• Population: A group of organisms of the same species who live in the same area at the same time. Studying populations helps understand evolutionary changes.
• Species: A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. Species are the basic unit of classification.
• Variation: Any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences or by the effect of environmental factors. Variation is the raw material for natural selection.
• Fitness: An organism's ability to survive and reproduce in a particular environment. Higher fitness means more offspring.
• Selection Pressure: Any factor that affects the survival or reproductive success of individuals within a population. Predation is a common selection pressure.
• Selective Advantage: A characteristic of an organism that permits it to survive and reproduce more effectively than other organisms in a population. Camouflage is a selective advantage.
• Founder Effect: The reduced genetic diversity that results when a population is descended from a small number of colonizing ancestors. This can lead to certain genetic disorders being more common.
• Bottleneck Effect: A sharp reduction in the size of a population due to environmental events (such as famines, earthquakes, floods, fires, disease, or droughts) or human activities. This reduces genetic diversity.
• Stabilizing Selection: A type of natural selection in which the population mean stabilizes on a particular non-extreme trait value. Human birth weight is an example.
• Disruptive Selection: Describes changes in population genetics in which extreme values for a trait are favored over intermediate values. This can lead to the formation of new species.
• Directional Selection: A mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction. Antibiotic resistance in bacteria is an example.
• Artificial Selection: The process by which humans breed other animals and plants for particular traits. Dog breeding is a prime example.
• Fossil: The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock. Fossils provide evidence of past life.
• Vestigial Structure: A structure in an organism that has lost all or most of its original function in the course of evolution. The human appendix is an example.
• Speciation: The formation of new and distinct species in the course of evolution. This often involves reproductive isolation.
• Divergent Evolution: The accumulation of differences between groups which can lead to the formation of new species. Darwin's finches are a classic example.
• Convergent Evolution: The process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. Sharks and dolphins have similar body shapes due to convergent evolution.
• Genetic Drift: Variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce. This can lead to random changes in allele frequencies.
• Mutation: The changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes. Mutations are the source of new genetic variation.
• Gene Flow: The transfer of genetic variation from one population to another. Migration is a form of gene flow.
• Sexual Selection: Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex. Peacock feathers are a result of sexual selection.
• Nonrandom Mating: Mating in which a pair of organisms is more likely to mate than would be expected under random chance. Assortative mating is a type of nonrandom mating.
• Isolating Mechanism: Features of behaviors, morphology, or genetics which prevent mating or gene flow between two species. These mechanisms are crucial for speciation.
• Pre-zygotic Isolating Mechanism: A form of reproductive isolation that occurs before the formation of a zygote. Examples include habitat isolation and temporal isolation.
• Post-zygotic Isolating Mechanism: A form of reproductive isolation that occurs after the formation of a hybrid zygote. Examples include hybrid sterility and hybrid inviability.

Diversity of Life

• Clade: A group of organisms believed to have evolved from a common ancestor. Clades are used in phylogenetic analysis.
• Node: The point on a branch where it splits, representing a hypothetical common ancestor. Nodes indicate points of divergence.
• Branch: A line representing a lineage evolving through time. Branches show evolutionary pathways.
• Common Ancestor: The most recent individual from which all organisms in a group are directly descended. Identifying common ancestors helps understand evolutionary relationships.
• Trait: A distinct variant of a phenotypic characteristic of an organism. Traits are used to construct phylogenetic trees.
• Divergent Evolution: The process by which initially similar species accumulate differences. This often leads to speciation.
• Speciation: The evolutionary process by which populations evolve to become distinct species. Speciation increases biodiversity.
• Gene Evolution: The change in the genetic makeup of a population over time. Gene evolution drives phenotypic changes.

Animal Physiology

• Animals: Multicellular, eukaryotic organisms in the biological kingdom Animalia. Animals exhibit diverse forms and functions.
• Inferior/Superior Vena Cava: Large veins that carry deoxygenated blood from the lower and upper body, respectively, into the right atrium of the heart. These veins ensure blood flow back to the heart.
• Right/Left Atria (sing. atrium): Upper chambers of the heart that receive blood. The atria contract to push blood into the ventricles.
• Right/Left Ventricle(s): Lower chambers of the heart that pump blood out. Ventricles have thicker walls than atria because they pump blood further.
• Atrioventricular valve(s): Valves between the atria and ventricles that prevent backflow of blood. The tricuspid valve is on the right, and the mitral valve is on the left.
• Semilunar valve(s): Valves at the exits of the ventricles that prevent backflow of blood into the heart. The pulmonary valve and aortic valve are semilunar valves.
• Right/Left Pulmonary Arteries: Vessels that carry deoxygenated blood from the right ventricle to the lungs. These arteries are part of the pulmonary circuit.
• Right/Left Pulmonary Veins: Vessels that carry oxygenated blood from the lungs to the left atrium. These veins complete the pulmonary circuit.
• Capillaries: Smallest blood vessels where gas exchange occurs. Capillaries have thin walls to facilitate diffusion.
• Veins: Vessels that carry blood towards the heart. Veins have valves to prevent backflow.
• Arteries: Vessels that carry blood away from the heart. Arteries have thick, elastic walls to withstand high pressure.
• Aorta: The main artery carrying oxygenated blood from the left ventricle to the rest of the body. The aorta branches into smaller arteries.
• Antigens: Substances that can trigger an immune response. Examples include bacteria, viruses, and pollen.
• Antibodies: Proteins produced by the immune system to help fight off antigens. Antibodies bind to antigens to neutralize them.
• Enzyme: A biological catalyst that speeds up chemical reactions. Enzymes are highly specific to their substrates.
• Active Site: The region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site is where catalysis occurs.
• Nose/Nostrils (Nasal cavity): External openings for air intake, leading to the nasal cavity. The nasal cavity filters and warms the air.
• Mouth (Oral cavity): Opening for food intake. The mouth is where digestion begins.
• Pharynx: The membrane-lined cavity behind the nose and mouth, connecting them to the esophagus. The pharynx is a common pathway for air and food.
• Larynx: The voice box, containing the vocal cords. The larynx is essential for vocalization.
• Epiglottis: A flap of cartilage at the root of the tongue, which depresses during swallowing to cover the opening of the trachea. The epiglottis prevents food from entering the trachea.
• Trachea: The windpipe, connecting the larynx to the bronchi. The trachea is reinforced with cartilage rings.
• Bronchi/us: The major air passages of the lungs which diverge from the windpipe (trachea). The bronchi branch into smaller bronchioles.
• Bronchiole(s): Any of the minute branches into which a bronchus divides. Bronchioles lead to alveoli.
• Alveolar Sacs: Clusters of alveoli in the lungs. Alveolar sacs increase the surface area for gas exchange.
• Alveoli: Tiny air sacs in the lungs where gas exchange occurs. Alveoli are surrounded by capillaries.
• Diaphragm: A dome-shaped muscle located at the base of the chest cavity, which contracts and flattens during inhalation. The diaphragm is the primary muscle for breathing.
• Ribs: Bones that protect the chest cavity. Ribs protect the lungs and heart.
• Intercostal muscles: Muscles located between the ribs that assist in breathing. Intercostal muscles help expand and contract the chest cavity.
• Lungs: Organs responsible for gas exchange. The lungs facilitate the exchange of oxygen and carbon dioxide.
• Cilia: Microscopic, hair-like structures that line the airways and help to remove mucus and debris. Cilia help keep the airways clean.
• Mouth: Where digestion begins. Saliva starts the chemical digestion of carbohydrates.
• Teeth: Used for mechanical digestion. Teeth break down food into smaller pieces.
• Tongue: Manipulates food and aids in swallowing. The tongue forms a bolus of food.
• Salivary Glands: Produce saliva, which contains enzymes that begin the chemical digestion of carbohydrates. Salivary amylase breaks down starch.
• Esophagus: A muscular tube that connects the pharynx to the stomach. Peristalsis moves food down the esophagus.
• Stomach: A muscular organ that churns food and mixes it with gastric juices. The stomach contains hydrochloric acid and pepsin.
• Gallbladder: Stores and concentrates bile produced by the liver. Bile emulsifies fats.
• Pancreas: Produces enzymes that digest carbohydrates, proteins, and fats, and it also produces hormones that regulate blood sugar levels. Pancreatic enzymes are secreted into the small intestine.
• Bile Duct: A tube that carries bile from the gallbladder to the small intestine. The bile duct joins the pancreatic duct.
• Small Intestine: The primary site of nutrient absorption. The small intestine has a large surface area due to villi and microvilli.
• Duodenum: The first part of the small intestine, where most chemical digestion takes place. The duodenum receives secretions from the pancreas and gallbladder.
• Ileum: The final section of the small intestine. The ileum absorbs vitamin B12 and bile salts.
• Jejunum: The middle section of the small intestine. The jejunum is the primary site for nutrient absorption.
• Large Intestine: Absorbs water and electrolytes from undigested food. The large intestine contains bacteria that aid in digestion.
• Rectum: A short tube at the end of the large intestine where waste material is compressed into a solid form before being eliminated. Feces are stored in the rectum.

Plant Biology

• Substrate: A molecule upon which an enzyme acts. For example, starch is a substrate for amylase.
• Lock-and-key: A model of enzyme activity that explains how a particular enzyme will only fit with one particular substrate. This model emphasizes the specificity of enzymes.
• Induced Fit: A model describing the interaction between enzyme and substrate. The enzyme changes shape to better fit the substrate.
• Denature: Modify (a protein or nucleic acid) especially by heat, acid, alkali, or ultraviolet radiation so that all of the original properties are removed or diminished. Denaturation affects enzyme function.
• Mucous: A slippery aqueous secretion produced by, and covering, mucous membranes. Mucous protects and lubricates tissues.
• Gas Exchange: The process where oxygen and carbon dioxide move between the bloodstream and the lungs. Gas exchange is essential for respiration.
• Mechanical Processing: The physical breakdown of food into smaller particles. Chewing is an example of mechanical processing.
• Chemical Action: The chemical breakdown of food into smaller molecules. Enzymes facilitate chemical action.
• Plants: Multicellular, eukaryotic organisms in the biological kingdom Plantae. Plants are autotrophs.
• Mosses: Small, non-vascular plants that reproduce via spores. Mosses are often found in moist environments.
• Liverworts: Small, simple plants often found in moist environments. Liverworts are similar to mosses.
• Hornworts: Non-vascular plants similar to liverworts but with horn-shaped sporophytes. Hornworts have a unique horn-shaped structure.
• Ferns: Vascular plants that reproduce via spores. Ferns have well-developed leaves and roots.
• Gymnosperm: Plants that have naked seeds that are not enclosed in an ovary. Conifers are gymnosperms.
• Angiosperm: Plants that have seeds enclosed in an ovary. Flowering plants are angiosperms.
• Monocot: A class of angiosperms that have one cotyledon in their seeds. Grasses and lilies are monocots.
• Dicot: A class of angiosperms that have two cotyledons in their seeds. Beans and roses are dicots.
• Cotyledon: An embryonic leaf in seed-bearing plants. Cotyledons provide nutrients to the developing seedling.
• Alternation of generations: A life cycle in plants and algae in which there is both a multicellular diploid form and a multicellular haploid form. This cycle involves both sporophyte and gametophyte generations.
• Xylem: Vascular tissue that transports water and minerals up from the roots. Xylem consists of dead cells.
• Phloem: Vascular tissue that transports sugars and other organic nutrients throughout the plant. Phloem consists of living cells.
• Cohesion-Adhesion: The properties of water that allow it to move up the xylem, where cohesion is the attraction between water molecules, and adhesion is the attraction between water molecules and the walls of the xylem. Cohesion-adhesion is crucial for water transport.
• Pressure-flow: The mechanism by which phloem sap moves through a plant. Sugars are actively transported into phloem, creating pressure.
• Transpiration: The process by which water is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration helps cool the plant.
• Root: The part of a plant that attaches it to the ground, typically underground, conveying water and nourishment to the rest of the plant. Roots absorb water and nutrients.
• Stem: The main body or stalk of a plant or shrub, typically rising above ground but occasionally subterranean. Stems support the plant and transport nutrients.
• Leaf: A flattened structure of a higher plant, typically green and blade-like, that is attached to a stem directly or via a stalk and functions as the primary site of photosynthesis. Leaves are the primary site of photosynthesis.
• Epidermis: The outer layer of tissue in a plant. The epidermis protects the plant from the environment.
• Mesophyll (spongy and palisade): The inner tissue (parenchyma) of a leaf, containing many chloroplasts. Mesophyll is where photosynthesis occurs.
• Cuticle: A protective and waxy or hard layer covering the epidermis of a plant. The cuticle prevents water loss.
• Carpel: The female reproductive organ of a flower, consisting of the stigma, style, and ovary. The carpel is essential for seed production.
• Pistil: The female parts of a flower, comprising the stigma, style, and ovary. The pistil receives pollen and develops into a fruit.
• Sigma: The part of the pistil where pollen germinates. The stigma is often sticky to capture pollen.
• Style: The stalk of the pistil down which the pollen tube grows. The style connects the stigma to the ovary.
• Anther: The part of a stamen that contains the pollen. The anther produces pollen grains.
• Filament: The stalk of a stamen. The filament supports the anther.
• Stamen: The male reproductive organ of a flower, consisting of the anther and filament. The stamen produces pollen.
• Ovule: