Genetics and Heredity
What is the genotype of an offspring produced by a GG parent crossed with a gg parent?
Gg
Which organelle converts nutrients into usable energy for the cell?
Mitochondria.
Which two products result from photosynthesis that are then used in cellular respiration?
Glucose (sugar) and oxygen (O2).
Which observation best indicates a reaction is exothermic?
A) Temperature increases B) Temperature decreases C) Color change only D) Substance changes shape
A) Temperature increases.
In most ecosystems, what is the ultimate source of energy that enters as light and is stored by producers?
The Sun.
In a Gg × Gg cross, what is the probability that an offspring will show the recessive phenotype?
25% (gg)
In the model Cell → Tissue → Organ → Organ system, what does this show about how body functions depend on levels of organization? (One-sentence answer.)
An organ system’s functioning depends on interactions among cells, tissues, and organs.
Which statement best describes the relationship — do photosynthesis products form respiration reactants, or vice versa?
Products of photosynthesis are reactants for cellular respiration (i.e., photosynthesis products form respiration reactants).
Yeast are mixed with glucose and sealed under oil to exclude oxygen; carbon dioxide is collected. Which metabolic process produced the CO₂?
A) Aerobic respiration of glucose B) Anaerobic respiration (fermentation) of glucose C) Fat metabolism D) Photosynthesis
B) Anaerobic respiration (fermentation) of glucose
When organisms die or produce waste, how do their materials (like carbon and nutrients) return to the air, soil, or water?
Decomposers break down dead organisms and waste, releasing carbon (as CO₂) and nutrients (like nitrogen and phosphorus) back into the abiotic environment (air, soil, or water).
Which type of reproduction (sexual or asexual) produces offspring genetically identical to the parent? Explain briefly.
Asexual reproduction — offspring are genetic clones (identical genotype) of the parent.
In cheek cells vs onion cells, which visible cell feature indicates a plant cell and why?
Presence of a cell wall (and rectangular cell shape) indicates a plant cell.
A plant model shows mitochondria producing CO₂, H₂O, and a “?” product. Name the “?” product produced by cellular respiration that cells use for work.
ATP.
When a blue solution is mixed with a colorless solution and a blue-green solid forms, which observation(s) best indicate a chemical reaction occurred? (Select two.)
A) A solid (precipitate) formed. B) Temperature changed. C) No visible change. D) Only color remained the same.
Answer: A) A solid formed; B) Temperature changed.
In a controlled experiment, four tanks of equal volume each contain different tadpole densities: 15, 60, 240, and 480 tadpoles. All other conditions (food, temperature, light) are the same. Tadpoles in the lowest-density tank reach larger average body mass faster than those in higher-density tanks. What is the best ecological explanation for this result?
Lower-density populations reduce competition for limited resources (food, space, oxygen), allowing individuals to access more resources and grow faster.
A chemical in a river causes color-changing mutations in crayfish genes passed to offspring. Which biological process best explains this change: mutation altering protein structure, environmental coloration, or gene deletion? (Choose the best explanation.)
Mutations in the gene for color can change the protein produced, causing white coloring in offspring (mutation alters protein).
How do hair cells in the cochlea help a person hear? Choose the correct mechanism (mechanical vs electromagnetic) and explain briefly.
Sound physically moves (mechanical stimulus) the hair cells in the cochlea; this movement is converted into nerve signals.
Which gas do plant cells release as a product of photosynthesis and which gas do they use during cellular respiration?
Plants release oxygen (O₂) during photosynthesis and use oxygen (O₂) during cellular respiration.
A reaction’s water temperature rises from 22°C to 35°C when two solutions mix. Is the reaction endothermic or exothermic? Explain.
Exothermic — it releases heat to the surroundings.
Strawberries reproduce by runners (asexual), and corn reproduces by pollination between two parents (sexual). Which offspring group will have lower genetic diversity and why?
Strawberries (asexual reproduction) will have lower genetic diversity because runners produce genetically identical clones of the parent.
Explain why sexual reproduction increases genetic variation. Give two distinct genetic mechanisms.
Sexual reproduction increases variation because meiosis (independent assortment and crossing over) and random fertilization mix parental alleles.
Describe how the respiratory and circulatory systems interact to exchange gases (which gases move which direction).
Oxygen diffuses from alveoli into blood; carbon dioxide diffuses from blood into alveoli; the circulatory system transports these gases to/from body cells.
What molecule produced by photosynthesis stores chemical energy that a cell can later use during cellular respiration?
Glucose (a sugar).
At 1 atmosphere pressure, a substance is solid at 0°C and liquid at 40°C. Describe the particle-level change that occurs when it melts.
Particles gain kinetic energy, move faster, and become less rigidly arranged so they can slide past each other (solid → liquid).
Name two ways matter is cycled between plants and people in a garden and give one specific example for each.
Carbon cycle — plants photosynthesize CO₂ into sugars that people eat; humans metabolize food and return CO₂ to the air by respiration. Nutrient cycle — fertilizer (abiotic nutrients like nitrogen and phosphorus) is taken up by plants and then consumed by people, moving nutrients from abiotic to biotic forms.