CRT Review Life Science

Heredity

100

In mice, brown (B) fur is dominant to white (b) fur. If a mouse with the genotype Bb is crossed with a mouse with a genotype Bb, what percentage of the offspring are expected to have brown fur? A. 25% B.50% C.75% D.100%

C. 75%

200

A hitchhiker's thumb (h) is a recessive trait compared to a straight-thumb (H). If an individual who is homozygous for a straight-thumb has offspring with an individual who is heterozygous with a straight-thumb, then what is the probability that the offspring will have a hitchhiker’s thumb? A. 75% B. 50% C. 25% D. 0%

D. 0%

300

Which of the following is the primary advantage of sexual reproduction when compared to asexual reproduction? A. There is a greater number of offspring.   B. There is more food available to offspring. C. There is greater genetic variety in offspring.   D. There is a longer development time for offspring.

C. There is greater genetic variety in offspring.

400

Animals kept in captivity, such as those in zoos, are provided with all of their basic needs, including food. Wild dogs, such as wolves, born in captivity cannot survive if released into the wild, because they cannot hunt. Wild cats, such as cougars, born in captivity can survive and will hunt if released into the wild. What is the best explanation for this phenomenon? A. Hunting is an innate behavior in all animals. B. Wild cats learn to hunt , but wild dogs inherit the trait. C.Hunting is an innate behavior in wild cats, but a learned behavior in wild dogs. D. Both wild cats and wild dogs must learn to hunt from their parents.

C.Hunting is an innate behavior in wild cats, but a learned behavior in wild dogs.

500

A change in genetic material that has the potential to produce variation within a species is a A. mutation. B. translation. C. transcription. D. replication.

A. mutation

Structures of Life

100

In which cell of the human body would you expect to find the most mitochondria? A. A muscle cell in the leg muscle of a runner. B. A cell of the stomach lining that manufactures digestive enzymes. C. A red blood cell that transports oxygen. D. A nerve cell that transmit signals to the brain stem.

A. A muscle cell in the leg muscle of a runner.

200

Complete the following statement about photosynthesis and plant growth to make it correct. Most plant growth comes from... A. soil nutrients used during photosynthesis. B. water used during photosynthesis. C. the energy used during photosynthesis. D. carbon dioxide used during in photosynthesis.?

D. carbon dioxide used during in photosynthesis.?

300

Which of the following is the correct ranking of organizational hierarchy of organisms from simplest to most complex? A. cells, organs, tissues, organ systems, organisms B. cells, tissues, organs, organ systems, organisms C. tissues, cells, organs, organ systems, organisms D. tissues, organs, cells, organ systems, organisms

B. cells, tissues, organs, organ systems, organisms

400

Which organ system in humans performs a similar function as shown by the arrows in the plant? (See Diagram) A. Circulatory B. Respiration C. Digestion D. Excretory

A. Circulatory

500

Malaria is a disease that is caused by a protist known as Plasmodium. When a mosquito bites a person infected with malaria, then bites a healthy person, the malaria-causing pathogens can infect the healthy person. What is the vector in this case? A. Human B. Plasmodium C. Mosquito D. Blood

C. Mosquito

Organisms and their Environment

100

There is a limit to how large any given population can grow. Which statement best explains why a population must eventually stop growing? A. A low female-to-male ratio develops as the population grows. B. Older individuals outnumber the younger members of the population. C. Natural selection causes the gene pool to shift as the population increases. D. The available resources necessary for life are used up by the population as it grows.

D. The available resources necessary for life are used up by the population as it grows.

200

A drought has caused the producer populations to significantly decrease. Which statement best describes an immediate effect caused by the decrease of producers? A. The hawk population would increase. B. The rabbit population would decrease. C. The sparrow population would increase. D. The mountain lion population would decrease.

B. The rabbit population would decrease.

300

In a marine ecosystem, disease killed most of the sea otters. This allowed the sea urchins and clams to increase in number. As a result, the sea gull population increased and the seaweed population decreased. Identify a secondary consumer in this marine ecosystem. (See A. Seaweed B.Clam C. Sea urchin D. Sea gull

D. Sea gull

400

The symbiotic relationship between a flower and the insect that feeds on its nectar is most likely an example of A. mutualism because the flower provides the insect with food, and the insect pollinates the flower. B. commensalism because the insect lives off the nectar but the flower does not benefit. C. parasitism because the insect harms the flower by removing the nectar. D. predation because the insect feeds on the flower and the flower dies.

A. mutualism because the flower provides the insect with food, and the insect pollinates the flower.

500

An incomplete food chain is shown below grass seed---> mouse ---> ? ---> hawk Which of the following organisms would best complete the food chain? A. Rabbit B. Robin C. Snake D. Tree

C. Snake

Diversity of Life

100

Although all modern breeds of dogs are members of the same species, they exhibit a wide range of physical characteristics. Which statement provides the best evidence that this range of characteristics is the result of artificial selection? A. The rate of change between modern dog breeds has decreased. B. Some modern dog breeds are poorly adapted to living in natural environments. C. The ancestors of modern dog breeds were more genetically diverse than breeds today. D. Many modern dog breeds are well adapted to living in both small and large populations.

B. Some modern dog breeds are poorly adapted to living in natural environments.

200

Which of the following best explains how the fossil record provides evidence that evolution has occurred? A.It indicates that forms of life existed on Earth at least 3.5 billion years ago. B. It indicates the exact cause of structural and behavioral adaptations of organisms.   C. It shows how the embryos of many different vertebrate species are very similar.   D. It shows that the form and structure of groups of organisms have changed over time.

D. It shows that the form and structure of groups of organisms have changed over time.

300

The explanation that diseases are caused by microorganisms is known as the A. cell theory. B. immune theory. C. germ theory. D. infection theory.

C. germ theory.

400

Which of the following provides the best evidence that organisms of two different species share a common ancestor? A. They live in the same ecosystem. B. They reproduce at the same time. C. They have similar DNA sequences. D. They have similar body movements.

C. They have similar DNA sequences.

500

Scientists discovered fossils of whale ancestors that have well-developed hip and thigh bones, which are typically used for walking by mammals. Modern whales most likely evolved from ancestors who A. lived in the sea, and then became better adapted for land. B. lived on land, and then became better adapted for the sea. C. evolved in the sea and remained in the sea. D. evolved on land and remained on land.

B. lived on land, and then became better adapted for the sea.

"In the Mix"

100

Students were asked to measure a piece of string. The actual length of the string was 8.25 cm long. Which of the following shows the measurements from the most accurate group and why? A.7.25cm, 7.75cm, 8.25cm, because these were the closest to the actual length. B. 7.2cm, 7.25cm, 7.3cm, because these had the most agreement between lengths. C. 8.25cm, 8.75cm, 9.25cm, because these had the most agreement between lengths. D. 8.2cm, 8.25cm, 8.9cm, because these were the closest to the actual length.

D. 8.2cm, 8.25cm, 8.9cm, because these were the closest to the actual length.

200

When investigating a new cancer-fighting drug, medical researchers give some of the subjects a pill that contains the drug. Some of the other subjects are given a pill that does not contain the drug. The drug-free pill serves what purpose in the design of the investigation? A. A control B. A variable C. A separate trial D. A qualitative comparison

A. A control

300

A student wants to test how music affects plant growth. He grows some plants in a bedroom window with music playing twenty-four hours per day. He grows a different variety of plants in his backyard with no music playing. What is the main problem with the design of this investigation? A. There is more than one variable in the experiment. B. There is no way to repeat the procedure. C. There are too many ways to graph the data. D. There is no way to accurately measure results.

A. There is more than one variable in the experiment.

400

Global warming is a debated subject among scientists. Some scientists support that human activities alone are dramatically warming the planet. Other scientists conclude that human activities are only partly to blame. Lastly, some scientists conclude that the Earth is warming due to natural cycles.  How are different conclusions possible if all scientists are looking at the same experiments and data? A. The scientists are experts in a narrow field so they ignore the data that is outside their expertise. B. Since there can be only one right answer, one scientist has the correct answer and the rest are wrong. C. Each scientist was able to fit the data together into a logical conclusion even though the resulting models were not identical. D. Scientists pick a theory and then focus on the data that supports their theory.

C. Each scientist was able to fit the data together into a logical conclusion even though the resulting models were not identical.

500

While conducting careful experimentation, a chemist discovered a new element. The international scientific community would most likely A. ignore the new data because it did not fit into the generally accepted periodic table. B. create a new classification system with the new information. C. disagree on how to incorporate the new data and create many classification systems based on personal preference. D. repeat the experiment and modify the current periodic table to include the new data.

D. repeat the experiment and modify the current periodic table to include the new data