scientists compare the dna of different organisms to understand evolutionary relationships what is this type of evidence called

ATI TEAS 7

TEAS 7 science practice

1. Scientists compare the DNA of different organisms to understand evolutionary relationships. What is this type of evidence called?

A. Morphological evidence (comparing body structures)
B. Biochemical evidence (comparing molecules like proteins)
C. Geographic distribution evidence (where organisms live)
D. Genetic evidence (comparing DNA sequences)

Correct answer: D

Rationale: A) Morphological evidence involves comparing body structures of organisms, which can provide information about evolutionary relationships based on physical similarities and differences. However, DNA comparison is a more direct and accurate method for understanding evolutionary relationships. B) Biochemical evidence involves comparing molecules like proteins, which can also provide insights into evolutionary relationships. However, DNA comparison is considered more reliable due to the direct relationship between DNA sequences and genetic information. C) Geographic distribution evidence refers to where organisms live and how their distribution may provide clues about evolutionary history. While this can be informative, it is not as direct or specific as comparing DNA sequences. D) Genetic evidence involves comparing DNA sequences of different organisms to understand their evolutionary relationships. DNA comparison is a powerful tool in evolutionary biology because it provides direct information about genetic similarities and differences, offering precise insights into evolutionary relationships.

2. Which of the following is an example of a polymer?

A. Methane
B. Ethanol
C. Polyethylene
D. Acetic acid

Correct answer: C

Rationale: The correct answer is C, Polyethylene. Polyethylene is a polymer composed of a large number of repeating ethylene units linked together, forming a long-chain molecule, characteristic of polymers. Methane, ethanol, and acetic acid are small organic molecules that do not demonstrate the repeating unit structure typical of polymers. Therefore, they are not examples of polymers.

3. Which of the following is a functional group commonly found in alcohols?

A. Carbonyl
B. Hydroxyl
C. Amine
D. Ester

Correct answer: B

Rationale: The hydroxyl functional group (OH) is commonly found in alcohols, giving them their characteristic properties. Alcohols are organic compounds that contain a hydroxyl group bonded to a carbon atom. The other choices, carbonyl, amine, and ester, are associated with different functional groups commonly found in other types of organic compounds. Carbonyl groups consist of a carbon atom double-bonded to an oxygen atom. Amines contain a nitrogen atom bonded to hydrogen atoms. Esters consist of a carbonyl group bonded to an alkoxyl group. Therefore, the correct answer is 'Hydroxyl (B),' as it specifically relates to the functional group present in alcohols, distinguishing it from the other options.

4. How do organisms maintain homeostasis?

A. By increasing their body temperature, blood pH, and fluid balance.
B. By undergoing biochemical processes and absorbing energy to increase entropy.
C. By undergoing biochemical processes to maintain the order of their external environment.
D. By using free energy and matter via biochemical processes to work against entropy.

Correct answer: D

Rationale: Organisms maintain homeostasis by utilizing free energy and matter through biochemical processes to counteract entropy, which helps in preserving internal stability. This process involves maintaining a balance within the organism's internal environment despite external changes, ensuring proper functioning and survival. Choice A is incorrect because increasing body temperature, blood pH, and fluid balance alone do not define the comprehensive process of maintaining homeostasis. Choice B is incorrect as absorbing energy to increase entropy goes against the concept of maintaining internal stability. Choice C is incorrect as maintaining the order of the external environment does not directly contribute to the organism's internal stability and balance.

5. Which compound is a component of baking soda and is important for maintaining pH balance in the body?

A. Potassium
B. Sodium
C. Calcium
D. Sodium bicarbonate

Correct answer: D

Rationale: The correct answer is D, Sodium bicarbonate. Sodium bicarbonate, commonly known as baking soda, is a compound that plays a crucial role in maintaining pH balance in the body. When ingested, sodium bicarbonate acts as a buffer, helping to regulate the body's pH levels. It is essential for various physiological functions. Choices A, B, and C are incorrect. Potassium, calcium, and sodium are important minerals in the body but are not components of baking soda or directly responsible for maintaining pH balance in the same way as sodium bicarbonate.