DNA, Proteins & Traits
This molecule contains the coded instructions for making proteins.
What is DNA?
This process uses light energy to make glucose.
Answer: What is photosynthesis?
This term describes all the living and nonliving parts interacting in an area.
What is an ecosystem?
This type of reproduction involves two parents and produces genetically different offspring.
What is sexual reproduction?
This term describes a species that enters a new ecosystem and causes harm.
What is an invasive species
Two body cells from the same organism have the same DNA, but one becomes muscle and one becomes bone. Explain why the cells can have different structures and functions.
Answer: What is differentiation? Different genes are turned on or off in different cells. This causes cells to make different proteins, which leads to different structures and functions.
Hydrilla uses carbon dioxide, water, and light energy. Identify the two main products/outputs of this process.
What is glucose and oxygen?
Prairie dog burrows provide homes for burrowing owls. Predict what would likely happen to the owl carrying capacity if prairie dog burrows decreased.
What is the carrying capacity for burrowing owls would decrease. Due to fewer burrows the owls would have less availablity to habitat or shelter.
Fraternal twins come from two different eggs and two different sperm. Explain why they may have different traits.
Each twin inherits a different combination of chromosomes and genes from the parents, so they may have different traits.
Hydrilla spreads when broken pieces are carried by boats. Identify one prevention method that would reduce spread without directly harming native plants.
Inspecting and cleaning boats before they enter or leave waterways would reduce the spread of Hydrilla.
A methyl group attaches to DNA but does not change the order of DNA bases. Explain how this could still affect a trait.
What is Methylation? Methylation can affect gene expression by turning genes on or off or reducing how much a gene is expressed. This can change the proteins made by the cell and affect traits.
A plant uses glucose to build starch, lipids, proteins, and DNA. Explain why glucose is important for plant metabolism beyond being an energy source.
What is the molecules can get rearranged into larger molecules? Glucose provides carbon-based building blocks that plants can rearrange into larger molecules needed for growth, repair, and reproduction.
Phytoplankton are a keystone species in an aquatic food chain. Explain how a decrease in phytoplankton could affect organisms at higher trophic levels.
A decrease in phytoplankton would reduce the amount of food and energy available to consumers. This could cause population decreases in organisms at higher trophic levels.
A Hydrilla plant breaks apart, and each piece grows into a new plant. Explain why the offspring are expected to have traits identical to the parent plant.
This is a form of asexual reproduction. The new plants come from pieces of the original plant and have the same DNA as the parent, so they are expected to have identical traits.
A town wants to control Hydrilla. Compare spraying herbicide with inspecting boats, and identify which solution is more likely to protect biodiversity.
Inspecting boats is more likely to protect biodiversity because it prevents Hydrilla from spreading without killing native plants or other organisms. Herbicides may reduce Hydrilla but could also harm non-target species.
Identical twins share the same DNA, but older identical twins may show more differences in gene expression than younger identical twins. Use methylation to explain this pattern.
What is methylgroups attached to DNA bases? Over time, environmental or lifestyle factors can cause different methylation patterns in each twin. These differences can change which genes are expressed, even though the DNA sequence is the same.
In a carbon-cycle model, plants remove carbon dioxide from the atmosphere and store carbon in biomass. Explain how both photosynthesis and cellular respiration affect carbon storage.
What is they recycle carbon? Photosynthesis removes carbon dioxide from the atmosphere and stores carbon in glucose and biomass. Cellular respiration breaks down glucose and releases carbon dioxide back to the environment.
Wolves were reintroduced to Yellowstone in 1995. Predict how wolf predation could indirectly increase willow growth and beaver populations.
Wolves reduce elk populations or change elk feeding behavior. With less browsing by elk, more willow plants survive and grow. More willows provide food and building material for beavers, so beaver populations may increase.
A disease kills many prairie dogs, but some survive and reproduce. Explain how a heritable resistance trait could become more common over generations.
Prairie dogs with the resistance trait are more likely to survive and reproduce. They pass the resistance trait to their offspring, so the trait becomes more common in the population over generations.
A wildlife management plan increases one predator population to restore ecosystem balance. Identify one possible benefit and one possible unintended consequence.
A possible benefit is that the predator may reduce an overpopulated prey species and help restore balance. A possible unintended consequence is that the predator may reduce other prey populations or disrupt other food-web relationships.
A gene is edited using CRISPR, changing the DNA code for a protein. Explain how this change could alter the protein’s function and affect the organism’s phenotype.
What is a change in DNA can change the mRNA codons, which may change the amino acid sequence of a protein. A different amino acid sequence can change the protein’s shape and function, which may change the organism’s trait.
Krill, an herbivore, feed near the ocean surface and release waste that sinks into deep ocean water. Explain how this process can move carbon from the atmosphere/biosphere system into long-term ocean storage.
Carbon dioxide is used by photosynthetic organisms near the surface. Krill eat those organisms, and carbon becomes part of the krill or their waste. When waste sinks to deep ocean water, carbon is moved away from the surface and can remain stored for a long time.
In a top-down trophic cascade, removing a predator changes herbivore behavior and plant survival. Construct a cause-and-effect chain showing how ecosystem stability could decrease.
Predator removed → herbivores increase or feed more freely → plants decrease → food and habitat decrease for other organisms → biodiversity decreases → ecosystem stability decreases.
Two insect species develop resistance to the same Bt toxin because they produce a similar protein. Explain how this could be used as evidence for relatedness or common ancestry.
Similar proteins are made from similar DNA instructions. If two species produce a similar resistance protein, it may suggest that they inherited similar genetic information from a common ancestor.
Evaluate this claim: “The best environmental solution is the one that removes the most organisms from the ecosystem.” Use biodiversity, trade-offs, and long-term stability in your response.
The claim is not accurate. Removing many organisms may reduce biodiversity and disrupt food webs. A better solution considers trade-offs, protects native species, and supports long-term ecosystem stability.