biology

A student noticed that the freshwater plant, Elodea, produced bubbles when placed in direct sunlight. What could the student most likely conclude?

Bubbles oxygen were produced as a result of photosynthesis

Which substance do biochemists often search for in fossils to help better understand the evolutionary relationships of the organism that formed the fossil?

DNA

Which best summarizes the role of DNA in the production of proteins?

DNA contains the instructions used to make proteins.

Which statement best explains how sweating during exercise maintains homeostasis?

It regulates body temperature.

What will most likely be the result as humans move into new areas, forests are clear cut and housing developments are built?

Many organisms will lose their homes because their habitats have been destroyed

What will most likely happen if a nonnative species is introduced into a stable ecosystem?

The native species will have to compete for resources with the nonnative species, and the ecosystem will become unbalanced.

Which statement best explains why animals are considered heterotrophic?

They are able to obtain nutrients by consuming other organisms or their products.

Some marine worms and mollusks go through similar larval stages during development. Which can be inferred about their relationship?

They share a common ancestor.

Scientists believe that the polar bear in Alaska and the brown bear in Russia evolved from a common ancestor. Which would be responsible for this evolutionary change?

geographic isolation

Which word equation best represents the process of cellular respiration?

glucose + oxygen ---> carbon dioxide + water

Which will most likely cause an increase in the frequency of genetic mutations in humans?

increased exposure to X-ray

During which phase of the cell cycle does most cell growth occur?

interphase

Waxes create a waterproof layer on the outside of some living organisms. To which group of organic molecules do waxes belong?

lipids

The chemical colchicine disrupts cell division. Which cell process would most likely stop if colchicine were added to a culture of human liver cells?

mitosis

What is the function of a restriction enzyme?

to cut DNA at a specific nucleotide sequence

Why must DNA replication have to occur before a cell can divide by mitosis?

to maintain the same number of chromosomes in the daughter cells as in the parent cell

What would most likely be produced when a cell with eight chromosomes undergoes mitosis?

two cells with eight chromosomes each

Which adaptation do ferns, gymnosperms, and angiosperms have that mosses do not have?

vascular tissue

Which transgenic organism has been used to clean up oil spills?

bacteria

Why are many farmers encouraged to plant different types of crops on the same land throughout the year?

It helps to preserve the quality of the soil.

This diagram shows a Paramecium, a unicellular protist. When a chemical is added to the pond water in which the Paramecium lives, the Paramecium stops moving. Which structure is most likely affected?

1

Having freckles is dominant over not having freckles. If two individuals heterozygous for freckles have a child, what is the propability the child will have freckles?

75%

A contractile vacuole helps protists eliminate excess liquid. This is a "pumping" process which reduces pressure inside the cell and prevents the cell from bursting. What is most likely the source of energy for this process?

ATP

A section of DNA has these bases TAG CAG TAC Which mRNA sequence is produced from this DNA section?

AUC GUC AUG

This diagram shows DNA fingerprints for a child and four adults. Which adult is most likely a parent of the child?

Adult 4

This diagram represents a closed terrarium exposed to sunlight What must happen for the carbon cycle to continue in this terrarium?

All organisms must continue to exchange gases.

These diagrams show a variety of cells from the same organism. How can cells from the same organism have such different shapes and functions?

During differentiation, different parts of the DNA in each type of cell are activated, resulting in the different structure and function of the cells.

Identical twin girls are separated at birth and cared for by two different families. After twenty years, the twins have different heights and weights. What is most likely the cause of these differences?

Each twin was provided a different diet and physical activities.

Genetically identical plants will produce either pink flowers or blue flowers, depending on the type of soil in which they are planted. What is most likely the explanation for the differences in flower color?

Environmental factors affect flower color.

In some ecosystems, wolves have been eliminated due to their threats to humans. How can the reintroduction of wolves benefit the ecosystem?

It can eliminate weak animals from the prey population, thereby decreasing competition for natural resources.

Which statement best describes natural selection?

Organisms better adapted to their environment are more likely to reproduce and pass on their traits to their offspring.

Multicelluar eukaryotic autotrophs belong to which kingdom?

Plantae

An antibiotic which was effective 20 years ago against a specific type of bacterial infection no longer works against the same kind of infection today. Which best explains why the antibiotic is no longer as effective as it was 20 years ago?

Resistant bacteria have survived and reproduced at a greater rate than nonresistant bacteria.

An insecticide kills most of the ants on a plant. Over time, it is determined that the insecticide is not as effective for killing ants. Which statement best explains this observation?

The ants killed by the insecticide and the surviving ants were genetically different.

Which most likely result in a negative growth rate in the human population of a country?

The death rate is higher than the birth rate.

Which effect could a mutation in mRNA have on the production of proteins?

The protein produced will have a different identity.

This diagram shows a red blood cell in a beaker that contains a solution with a higher salt concentration than that inside the red blood cell. What will happen to the red blood cell in this environment?

The red blood cell will shrink from losing water molecules

Which best explains why the rate of a biochemical reaction decreases at high temperatures?

The shape of the enzyme changes.

What will most likely occur if the population of the world continues to increase at predicted rates?

There will be more rapid depletion of natural resources.

This is a dichotomous key for selected arthropods. To which order does the caddis fly belong?

Trichoptera

During translation, what does the tRNA deliver to the ribosomes?

amino acids

Which molecules are joined together to make proteins?

amino acids

Which of these cells in the human body is specialized to transport oxygen throughout the body?

blood cell

How are mitosis and meiosis similar?

both require DNA replication

How do some chemicals increase the risk of a person getting cancer?

by causing cell mutations

Salivary amylase is an enzyme in humans that breaks down starches. What substance would humans have difficulty digesting without this enzyme?

carbohydrates

Plant cells are able to produce their own food. This process happens in which structure?

chloroplast

What do both prokaryotic and eukaryotic cells contain?

cytoplasm

Some scientists claim recent evidence suggests birds should be reclassified to share more taxonomic groups with dinosaurs. What type of evidence would provide the best support for this claim?

evidence showing birds shared a common genetic history with dinosaurs

Which process can occur in both mitosis and meiosis?

gene mutation

What is the basis for the earliest classification system of organisms?

physical characteristics

What activity most contributes to the depletion of the ozone layer?

release of CFC's

Which graph best illustrates the growth of a population introduced into an environment with limited resources?

s curve

Which is a primary function of a vacuole in a cell?

storage

In nature, which type of behavior causes animals to produce aggressive displays and sounds?

territoriality

Which would be a desirable trait scientists may want to create in a transgenic plant?

the ability to resist insects

What determines the function of a specialized cell?

the active genes in the cell

What carries the instructions for making amino acids in a protein?

the sequence of nitrogen bases on the mRNA

What is the difference between the DNA of a dog and the DNA of a fly?

the sequence of nucleotides

How does the body of a runner keep up with the demand for energy when cellular oxygen levels are low?

through anaerobic respiration in the cytoplasm