which of these pairs represents an example of convergent evolution

ATI TEAS 7

TEAS 7 practice test science

1. Which of these pairs represents an example of convergent evolution?

A. Humans and chimpanzees
B. Bats and birds
C. Dolphins and sharks
D. Snakes and earthworms

Correct answer: B

Rationale: Convergent evolution refers to the process by which different species independently evolve similar traits or characteristics due to similar environmental pressures. In the case of bats and birds, both have evolved wings for flight despite not sharing a recent common ancestor with wings. Bats are mammals, while birds are avians, yet they both have wings adapted for flight, which is a classic example of convergent evolution. A) Humans and chimpanzees share a common ancestor and have not independently evolved similar traits. C) Dolphins and sharks are not closely related, and their similarities are due to adaptations to their aquatic environment rather than convergent evolution. D) Snakes and earthworms belong to different classes (reptiles and annelids, respectively) and do not share recent common ancestors, making their similarities not a result of convergent evolution.

2. Where does bile, a substance that aids in digesting fats, originate from?

A. Stomach
B. Pancreas
C. Liver
D. Gallbladder

Correct answer: C

Rationale: Bile is produced by the liver to aid in the digestion and absorption of fats. The liver produces bile, which is then stored and concentrated in the gallbladder before being released into the small intestine to facilitate fat digestion. The stomach (option A) is responsible for the initial digestion of food through gastric juices but does not produce bile. The pancreas (option B) secretes digestive enzymes like lipase to further break down fats in the small intestine but does not produce bile. The gallbladder (option D) stores and concentrates bile but does not produce it.

3. What type of reaction is represented by the following equation: 2Câ‚†Hâ‚â‚„ + 19Oâ‚‚ â†’ 12CO + 14Hâ‚‚O?

A. Substitution reaction
B. Acid-base reaction
C. Enzyme reaction
D. Combustion reaction

Correct answer: D

Rationale: The given chemical equation represents a combustion reaction. Combustion reactions involve the burning of a hydrocarbon (Câ‚†Hâ‚â‚„) in the presence of oxygen (Oâ‚‚) to produce carbon monoxide (CO) and water (Hâ‚‚O). Combustion reactions typically release heat and light energy. In this case, the reactants are a hydrocarbon and oxygen, resulting in the formation of carbon monoxide and water. Choices A, B, and C are incorrect because the reaction does not involve substitution, acid-base reactions, or enzyme catalysis. Combustion reactions are characterized by the rapid combination of a substance with oxygen, leading to the production of heat and light energy.

4. What do lacteals absorb in the small intestine?

A. Carbohydrates
B. Lipids
C. Proteins
D. Nonpolar nutrients

Correct answer: B

Rationale: Lacteals are lymphatic capillaries in the small intestine that specialize in absorbing dietary lipids. These lipids are then transported into the lymphatic system for further processing and distribution throughout the body. Choice A (Carbohydrates) is incorrect because carbohydrates are primarily digested and absorbed in the small intestine by enzymes and transported to the liver. Choice C (Proteins) is incorrect because proteins are broken down into amino acids and absorbed in the small intestine, mainly by the villi. Choice D (Nonpolar nutrients) is incorrect as it is a vague term and not specific to what lacteals absorb, which are primarily lipids.

5. Which of the following layers of the skin does not contain blood vessels?

A. Hypodermis
B. Dermis
C. Epidermis
D. Hyperdermis

Correct answer: C

Rationale: The epidermis is the outermost layer of the skin and is avascular, meaning it does not contain blood vessels. It receives nutrients through diffusion from the underlying dermis. The hypodermis is the subcutaneous tissue beneath the dermis and contains blood vessels. The dermis is the layer of skin between the epidermis and hypodermis, which contains blood vessels, nerves, hair follicles, and sweat glands. 'Hyperdermis' is not a correct anatomical term and is not a layer of the skin, making it an incorrect choice for this question.