Answer:
The correct answer is: c) usually produces offspring that cannot reproduce.
Explanation:
Hybridization, also knowns as selective breeding, is an <u>artificial process</u><u> that involves selecting parents with specific characteristics in order to obtain an offspring with the same traits</u>.
Hybridization is very common and has been performed by humans for thousands of years: from selective breeding crop plants, to do so with dogs in order to create more desirable breeds.
Option A is incorrect because hybridation does not occur in nature, it is an artificial process.
Option B is incorrect because hybridation often happens when the selected parents are chosen to reproduce (by a human).
Option D is correct because an important amount of hybrids are sterile (for example: mules).
Option D is incorrect as well because the offspring is not identical: it shares a combination of genes from both parents.
Answer:
The correct option is <u><em>A. they evolved from land mammals.</em></u>
Explanation:
The process of evolution explains how closely one organism is to another based on their common ancestors. Scientists believe that those organisms which show many similarities in their structures or functions might have evolved from a common ancestor in the past.
As in the above-mentioned question, scientists have observed that cetaceans lack gills and breath air, this is a property of land mammals. The cetaceans have fin bones which are similar to the limb bones. As limb bones are present in land mammals, hence they cetaceans and land mammals might have common ancestors in the past.
The correct answer is d. spinal cord.
Spinal cord is a bundle of neurons which starts from the brain and runs down the entire length of the back of the body. The spinal cord acts as a main means to transmit the messages between the brain and the body.
Sensory or efferent neurons carry the information from the perimeter of the body and pass to the central nervous system whereas the motor or efferent neurons act as a communication channel and carry the information from the nervous system to various glands and muscles.
