Which cell organelle is responsible for helping the cell maintain homeostasis.
Approximately 44% of the world’s fish produced for human consumption comes from aquaculture, which is the farming of fish and other aquatic organisms. This practice has increased the food supply and has also allowed over-fished wild populations to increase. As a result of genetic modifications, farm-raised fish usually grow faster and are typically larger than those in the wild. However, there are some negative environmental effects associated with fish farming. Sea lice, a parasite of salmon, have spread quickly through some farms and have also been found in waters around the farms. Farm-raised fish sometimes escape through breaks in the sea cages. There is a concern that these escaped fish could negatively affect ocean ecosystems. Researchers are studying methods that can be used to reduce the possible negative effects of fish farming. Improvements in engineering could make the sea cages where the farmed fish are raised more secure. Another suggestion involves raising farmed fish that have extra chromosomes. This would prevent them from reproducing with wild fish that have the normal number of chromosomes. Identify concerns that individuals might have as the number of fish farms increase. Select all that apply.
Monarch butterfly populations have fallen by 90% in less than 20 years. Monarchs west of the Rocky Mountains overwinter on the central coast of California. Their numbers have dropped from 1.2 million to only 200,000. East of the Rocky Mountains, monarchs overwinter in Mexico. In 2002, their numbers were down by about 500 million. One reason for the decrease in monarch numbers is the increased planting of corn, cotton, and soybeans that are genetically modified (GM) to be resistant to weed killers containing glyphosate. With the increased use of these GM plants, increased amounts of the weed killers are being sprayed on fields where these crops are grown. These weed killers do not kill monarchs and other insects. They kill only plants such as milkweed that do not contain the resistance gene. Mature adult monarch butterflies lay their eggs on milkweed plants. The larvae (caterpillars) eat only milkweed. Adults seek out flower nectar from a variety of plants. Stages of the monarch life cycle are represented below.
Select the best answer to how weed killers containing glyphosate is responsible for a decrease in the size of monarch populations, since monarchs do not feed on genetically modified corn or soybeans during any stage of their life cycle
The image below is the translation process of Protein synthesis. This part of the process takes place in the organelle. Label the following letters correctly to receive credit.
DNA sequencing is a specific process and follows a number steps that take place a the same time. Place the sequence in the correct order.
The DNA ligule glues Ozaki fragments together
DNA unzips
DNA starts to unwind
The DNA polymerase build new nitrogen bases
Two identical semiconservative DNA molecules are created
Florida residents have been experiencing the consequences of “red tides,” excessive growth of the algae Karenia brevis (K. brevis). This species of algae is a single-celled organism that releases brevetoxin, a dangerous nerve toxin that can be fatal to animals. Even though shellfish, which can eat K. brevis, are not affected by this algae, many fish and other marine organisms, such as dolphins and manatees, are paralyzed by the toxin. This toxin prevents the organisms from carrying out the process of cellular respiration. The red tides usually appear in late summer or early fall. Researchers are not sure what causes red tides. A variety of factors seem to be associated with their occurrence. These factors include warmer ocean temperatures, heavy rainfall, and pollution from fertilizers. The model below represents a typical food web present in Gulf Coast waters.
Identify one abiotic factor mentioned in the passage that could be causing the red tides in Florida
Poisonous South American cane toads were introduced into Australia in 1935 in an attempt to control a beetle that was eating sugar cane crops. However, the toads did not control the beetles and, instead, they caused an environmental disaster. Today, the toad population is estimated to be greater than 200 million. As the invasive toads spread westward across northern Australia, many native species were negatively affected. For example, in the years since the toads’ introduction, scientists have observed that the entire population of the northern quoll, a small squirrel-sized carnivore, has declined more than 75%. The decline is due to the fact that the quolls mistake the poisonous toads for something that they can safely eat. When they eat the toads, they die from the poison that the toads produce. The northern quolls may soon become extinct if something cannot be done to save them. Recently, some quolls were found to have a genetic trait that makes them uninterested in preying on the toads. Scientists have now discovered that these quolls with “toad-smart genes” can pass them on to their offspring. The scientists plan to release quolls that avoid eating the toads into native populations, hoping that they will breed and produce offspring that also avoid eating the toads, thus saving the species from extinction. Select the two best answers on how the northern quoll extinction would affect the other organisms in the ecosystems where they once lived.
According to the information in the chart, which finch species is best adapted to feed on insects that live under the bark of trees?
The existing species of South American bats depend upon a wide variety of food sources, yet they have evolved from a single population of insect eating bats. The diagram below summarizes the feeding habits of some species of South American bats.
The adaptations shown by each species of bat will most likely cause the total number of bats to
Bed bugs aren’t just a problem from centuries past. Bed bug infestations have been increasing for more than a decade. This has been largely due to the insects’ ability to quickly develop resistance to the insecticides used to kill them. Bed bugs have a tough outer coat, called a cuticle, which helps protect them. Researchers have found that some resistant bed bugs have gene mutations that allow the cuticle to produce substances that break down the insecticides. Others have gene mutations that direct the building of biological pumps, which allow the cuticle to pump the harmful insecticide out of the bug.
The substances which allow the bed bugs to break down insecticides and the biological pumps which remove the insecticides from the bed bugs are examples of
A gene mutation resulting in insecticide resistance would most likely increase in the bed bug population because
The diagram represents three groups of red blood cells. Groups A and B were each placed in different solutions for the same period of time. Which image is representing the movement of water in and out of a cell. What type of passive transport is represented in images below?
The diagram represents three groups of red blood cells. Groups A and B were each placed in different solutions for the same period of time.
A student placed artificial cells, each containing a 25% sugar solution, into three different beakers containing sugar solution which varied in concentration from 0% to 25%. The setups are shown below.
The student collected data on the mass of each artificial cell. Which cell would have the greatest change in mass after 24 hours.
A cladogram of five species is shown.
Based on the cladogram, the ancestral species most likely had —
Students created note cards comparing characteristics of eukaryotic and prokaryotic cells.
Which set of note cards most accurately compares these cells?
Which principle of Mendel's Law of Segregation states that during gamete formation, the two alleles for a hereditary trait segregate or separate from each other so that each gamete carries only one allele for each trait?
Base your answers to questions 38 and 39 on the diagram below and on your knowledge of biology. The diagram represents a series of events that occur within living organisms.
Cell structure X is a....
The model below summarizes one pathway of energy transfer in an ocean ecosystem.
The type of organism represented by box X could be
DNA | Protein Synthesis | |
|---|---|---|
Nitrogen base Uracil | ||
Uses amino acids | ||
Made up of nucleotides | ||
Double helix | ||
single stranded | ||
builds proteins | ||
Takes place in the nucleus | ||
Uses transcription & translation | ||
Create a semiconservative model |

Which principle of Mendelian genetics states that alleles for different genes segregate independently of one another during gamete formation, provided that the genes are located on different chromosomes or are far apart on the same chromosome?
Active transport | Passive transport | Both Active and Passive Transport | |
|---|---|---|---|
Requires Energy | |||
Movement of materials in and out of a cell | |||
No energy require | |||
Endocytosis and exocytosis | |||
Osmosis, diffusion, facilitated diffusion | |||
High to low | |||
Low to high | |||
against the concertation gradient | |||
with the concentration gradient |