Explain Environmental Influences on Traits - Biology
- What is the key difference between acclimation and adaptation?
- Acclimation is within a lifetime; adaptation evolves across generations. Acclimation occurs quickly; adaptation takes generations.
- Which environmental factor can cause lung disease and alter health-related traits over time?
- Tobacco smoke exposure. Toxic chemicals damage lung tissue over time.
- Which environmental factor can increase mutation rate and thereby affect traits?
- Radiation (e.g., UV or ionizing radiation). High-energy radiation damages DNA structure directly.
- Which environmental factor is most directly linked to tanning in humans?
- Ultraviolet (UV) radiation exposure. UV light triggers melanin production as protection.
- Which option best supports a genotype-by-environment interaction in two genotypes across two diets?
- The diet effect differs between genotypes (nonparallel responses). Interaction occurs when genotypes respond differently.
- What is the definition of gene expression?
- Use of genetic information to make RNA and proteins. Process of turning genes into functional products.
- What is the definition of an acquired characteristic?
- A trait change due to environment, not inherited genetically. Traits gained during life, not passed to offspring.
- What is the definition of a teratogen?
- An environmental agent that disrupts embryonic development. Chemical or physical factor causing birth defects.
- Which option is an example of an environmental effect during early development with lasting impact?
- Prenatal alcohol exposure affecting brain development. Developmental exposure creates permanent changes.
- Which nutrient deficiency is most directly linked to reduced hemoglobin production?
- Iron deficiency. Iron is essential for hemoglobin synthesis.
- Which environmental factor during development can reduce adult height even with tall-parent genes?
- Poor nutrition (especially protein and calories). Malnutrition limits growth despite genetic potential.
- Which term describes traits strongly influenced by environment, making them vary continuously?
- Quantitative traits. Continuous variation due to environmental sensitivity.
- Which epigenetic change commonly reduces gene expression by tightening DNA packing?
- DNA methylation. Chemical modification that silences gene transcription.
- Which human trait is a classic example of multifactorial inheritance with environmental effects?
- Body mass (weight) or height. Many genes and nutrition both influence these traits.
- What is the correct definition of a selective pressure?
- An environmental factor that affects survival or reproduction. Environmental conditions that influence evolutionary fitness.
- Which option is an example of environment affecting phenotype without changing genotype?
- Skin tanning after UV exposure. Phenotypic response without genetic change.
- Which environmental condition can trigger increased red blood cell production in humans?
- Low oxygen at high altitude. Body compensates for reduced oxygen availability.
- What pigment increases in human skin in response to UV exposure?
- Melanin. Dark pigment that protects skin from UV damage.
- What is the primary reason identical twins can show different phenotypes?
- Different environments and epigenetic differences. Environment and gene regulation vary even with same DNA.
- Which option best describes why PKU requires a special diet despite being genetic?
- Dietary phenylalanine level affects symptom development. Restricting substrate prevents toxic metabolite buildup.
- What is the definition of an environmental influence on a trait?
- A non-genetic factor that affects phenotype expression. External conditions that modify how genes are expressed.
- What is the name of the trait pattern where many genes and environment both influence outcome?
- Multifactorial trait. Multiple genes plus environment create complex patterns.
- What is photoperiodism?
- Physiological response to day length. Plants use day length to time seasonal responses.
- Identify the correct term for reduced growth due to long-term nutrient shortage.
- Stunting. Chronic malnutrition impairs normal growth processes.
- Which environmental factor most directly affects stomatal opening in many plants?
- Water availability (drought) and humidity. Water stress triggers stomatal closure responses.
- Which option best describes how temperature can affect enzyme-related traits?
- Temperature alters enzyme activity and reaction rates. Heat changes protein shape and metabolic rates.
- Identify the correct term: environmental cues changing gene expression without changing DNA sequence.
- Epigenetic regulation. Chemical modifications control gene activity levels.
- Identify the best interpretation: identical twins differ in asthma severity in different cities.
- Environmental exposure differences affected phenotype. Different environments caused phenotypic variation.
- Which environmental factor most directly increases muscle size in a trained person?
- Exercise (mechanical load and training). Resistance training stimulates muscle protein synthesis.
- What is phenotypic plasticity?
- Ability of one genotype to produce different phenotypes. Same genes can create different traits in different conditions.
- What term describes the observable characteristics of an organism?
- Phenotype. The visible or measurable traits of an organism.
- Which statement is correct: acquired characteristics are inherited or not inherited?
- Not inherited (they do not change DNA sequence in gametes). Only changes in gamete DNA are passed to offspring.
- What is a reaction norm in the context of environmental effects on traits?
- Pattern of phenotypes a genotype shows across environments. Shows how one genotype varies across environments.
- Which pigment allows plants to detect day length for photoperiod responses?
- Phytochrome. Light-sensitive protein that measures day length.
- What is acclimation?
- Reversible phenotypic adjustment to environmental change. Short-term adjustment to environmental changes.
- Which teratogen is strongly associated with fetal alcohol spectrum disorders?
- Alcohol (ethanol). Crosses placenta and damages developing brain tissue.
- Which environmental factor can change plant growth form by altering gene expression patterns?
- Light conditions (intensity and photoperiod). Light quality and duration regulate plant development.
- Which option best explains why hydrangea flower color can change with soil conditions?
- Soil pH affects pigment chemistry and ion availability. Acidic conditions alter anthocyanin pigment structure.
- Which environmental factor most directly influences the severity of lactose intolerance symptoms?
- Amount of lactose consumed (diet). Symptom severity depends on dietary intake.
- What hormone primarily stimulates red blood cell production in response to low oxygen?
- Erythropoietin (EPO). Kidney hormone that stimulates blood cell production.
- Identify the correct conclusion: two plants with the same genotype differ in height in sun vs shade.
- Environment influenced phenotype (phenotypic plasticity). Same genotype responds differently to light conditions.
- Which term describes how different genotypes respond differently to the same environment?
- Genotype-by-environment interaction (G×E). Different genetic variants respond uniquely to conditions.
- What is epigenetics?
- Heritable changes in gene expression without DNA sequence change. Gene activity changes without altering DNA sequence.
- Which concept best explains why a single genotype may yield different phenotypes in different environments?
- Phenotypic plasticity. Flexible response of genotype to environmental variation.
- Choose the correct classification: a scar from injury is genetic, environmental, or both?
- Environmental (acquired characteristic). Physical injury creates non-genetic trait change.
- What term describes the genetic makeup that can influence traits?
- Genotype. The complete set of genes an organism inherits.
- What is the correct environmental management for phenylketonuria (PKU) to reduce symptoms?
- Low-phenylalanine diet started early in life. Early intervention prevents irreversible brain damage.
- What is the correct relationship among phenotype, genotype, and environment?
- Phenotype results from genotype interacting with environment. Genes provide potential; environment determines expression.
- Which infectious agent in pregnancy can cause congenital defects and hearing loss?
- Rubella virus. Viral infection during pregnancy affects development.
- Which statement correctly distinguishes natural selection from environmental effects within one lifetime?
- Selection changes allele frequencies; environment changes phenotype expression. Selection acts across generations; environment within lifetime.