The Prickly Pear Cactus Has Evolved Spines That Are Its

question 16

Multiple Choice

The prickly pear cactus has evolved spines that are its actual leaves. The evolutionary adaptation of these modified leaves is

• A)defence.
• B)protection from UV radiation.
• C)to increase water absorption.
• D)to take in carbon dioxide for photosynthesis.
• E)Two of the above statements are correct.

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Definitions:

DNA

Deoxyribonucleic acid, a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms.

Ultraviolet Radiation

A form of electromagnetic radiation with a wavelength shorter than that of visible light but longer than X-rays, which can have effects on the skin such as tanning or burning.

Rod-Shaped

Describing an object or organism that has a long, slender form, similar to a rod or stick.

Paired Structures

Structures in the body or in other systems that occur in pairs, often symmetrical on either side of the body or system.