1. The measurable electrical activity of the brain is recorded by a:

A. CAT scan
B. MRI scan
C. Electroencephalogram (EEG)
D. X-ray

Correct answer: C

Rationale: The correct answer is C: "Electroencephalogram (EEG)". An EEG is a non-invasive test that measures the electrical activity of the brain by placing electrodes on the scalp. It is specifically designed to record brain wave patterns, making it a valuable tool in diagnosing conditions such as epilepsy, sleep disorders, and brain injuries. A CAT scan (A) and MRI scan (B) are imaging techniques that show the structure of the brain, while an X-ray (D) is not typically used to measure brain electrical activity.

2. Organisms that break down dead organisms and return nutrients to the environment are called:

A. Producers
B. Decomposers
C. Consumers
D. Parasites

Correct answer: B

Rationale: Rationale: Decomposers are organisms that break down dead organisms and organic matter, such as bacteria, fungi, and some insects. They play a crucial role in the ecosystem by breaking down complex organic materials into simpler forms, releasing nutrients back into the environment for other organisms to use. Producers (option A) are organisms that produce their own food through photosynthesis, consumers (option C) are organisms that consume other organisms for energy, and parasites (option D) are organisms that live on or in another organism and benefit at the host's expense.

3. A study finds a correlation between increased ice cream consumption and lower crime rates. What is the MOST likely explanation for this observation?

A. Ice cream directly reduces criminal behavior.
B. People who commit crimes eat less ice cream.
C. A third factor, like hot weather, influences both.
D. The study design is flawed and the connection is false.

Correct answer: C

Rationale: The most likely explanation for the correlation between increased ice cream consumption and lower crime rates is a third factor influencing both variables. In this case, hot weather could be the common factor as both ice cream consumption and crime rates tend to increase during warmer months. This scenario illustrates the importance of considering confounding variables when interpreting correlations.

4. What happens during a physical change in matter?

A. A new substance with different properties is formed
B. The chemical composition of the substance changes
C. The original substance can be recovered by physical means
D. Energy is either released or absorbed

Correct answer: C

Rationale: During a physical change in matter, the original substance undergoes a change in its physical state or appearance without any change in its chemical composition. This means that the original substance can be recovered by physical means, such as melting, freezing, boiling, or condensing. No new substance is formed (option A), the chemical composition remains the same (option B), and energy changes can occur but are not a defining characteristic of a physical change (option D).

5. What is the main function of the gallbladder?

A. To store and concentrate bile
B. To produce digestive enzymes
C. To absorb nutrients
D. To neutralize stomach acid

Correct answer: A

Rationale: Rationale: The gallbladder is a small organ located beneath the liver that plays a crucial role in the digestive system. Its main function is to store and concentrate bile, a digestive fluid produced by the liver. Bile is released from the gallbladder into the small intestine to help with the digestion and absorption of fats. The gallbladder acts as a reservoir for bile, allowing it to be released in a controlled manner when needed to aid in the digestion of fatty foods. Therefore, option A is the correct answer as it accurately describes the main function of the gallbladder.

6. Which type of isomerism arises due to differences in the arrangement of atoms around a double bond?

A. Chain isomerism
B. Functional group isomerism
C. Cis-trans isomerism
D. Stereoisomerism

Correct answer: C

Rationale: The correct answer is C: Cis-trans isomerism. Cis-trans isomerism, also known as geometric isomerism, arises due to differences in the spatial arrangement of atoms around a double bond. In cis isomers, similar groups are on the same side of the double bond, while in trans isomers, similar groups are on opposite sides. This type of isomerism is specific to compounds with restricted rotation around a double bond, leading to distinct spatial arrangements and different properties. Chain isomerism (A) refers to isomers with different carbon chain arrangements, functional group isomerism (B) involves different functional groups, and stereoisomerism (D) encompasses all isomers that have the same connectivity but differ in spatial arrangement.