Question

selective breeding

1. modern dogs are direct descendants of the gray wolf. they first appeared about 130,000 years ago. today, there are about 150 different breeds of domestic dog, a few of which are shown below.

an image showing a gray wolf and various modern domestic dog breeds with the caption: all modern domestic dogs are descendants of the grey wolf. (adapted from www.pbs.org)
which process brought about by humans created the great variety of modern dogs?

1. over the past few thousand years, humans have helped to bring about changes in many plant and animal species in order to make them more useful. examples include strong workhorses, hunting dogs, large - eared corn, and beautiful flower varieties. which technique was most likely used to develop this new variety of organisms?

1. selective breeding has been used to improve the racing ability of horses.

a. define selective breeding and state how it would be used to improve the racing ability of horses.
b. state one disadvantage of selective breeding.

Explanation:

Question 1

The problem is about the process by which humans created the variety of modern dogs from gray wolves. Selective breeding (also called artificial selection) is the process where humans choose organisms with desired traits to breed, leading to offspring with those traits. Over time, this creates different breeds, like the various dog breeds from gray wolves.

The examples given (strong workhorses, hunting dogs, large - eared corn, beautiful flower varieties) are all created by humans choosing organisms with desirable traits and breeding them. This is the process of selective breeding (artificial selection), where humans intervene to select for specific traits to develop new varieties of organisms.

1. Define Selective Breeding: Selective breeding is the process by which humans deliberately choose parent organisms with desirable characteristics (traits) to breed together, with the goal of producing offspring that inherit those desirable traits.
2. Using it to Improve Racing Ability of Horses: To improve the racing ability of horses, breeders would first identify horses that have desirable racing - related traits. These traits could include speed, stamina, agility, and a good racing conformation (body structure suitable for racing). Then, they would breed these high - performing horses together. Over successive generations, the offspring would inherit the desirable racing traits from their parents, and through continued selection of the best - performing offspring for breeding, the overall racing ability of the horse population (or the breed) would be improved.

Answer:

The process is selective breeding (or artificial selection). Humans selected gray wolves with certain traits (like size, temperament, appearance) and bred them, over generations, to produce the different domestic dog breeds we see today.

Question 2