Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, a
nd cabbage. Therefore, which of the following statements is correct?A) In this wild mustard, there is enough heritable variation to permit these different varieties.B) Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics.C) Natural selection is rare in wild populations of wild mustard.D) In wild mustard, most of the variation is due to differences in soil or other aspects of the environment.
A) In this wild mustard, there is enough heritable variation to permit these different varieties
Explanation:
The mentioned varieties were created by artificial selection for various traits in the wild mustard Brassica. This wild type plant was native to Europe and Asia and had a wild range of genetic variations to allow the development of different strains.
For example, the selection of strains that formed the overlapping leaves led to the development of cabbage. Repeated breeding allowed this trait to become prominent as it is in the modern cabbages. Likewise, the strains of the wild cabbage that had prominent storage stem gave rise to kohlrabi while the strains with enlarged axillary buds were selected for the development of brussels sprouts.
➷ It makes the circulatory system more efficient and helps to keep a constant body temperature. It allows an efficient supply of oxygenated blood to the body cells.
