<span>The discovery of thornless plants was made around the turn of the 20th century. To name one such thornless plant, particularly, the Blackberry plant, the deviation from the thorned blackberry canes were discovered in the United States. Since then, several different thornless blackberry varieties have been cultivated for fruit gardens.</span>
        
             
        
        
        
Answer: 
1: B
2: C
3: D
4: D
5: B
6: C
7: A
Explanation:
Alleles: alternative forms of a gene
Gametes: sex cells that are the product of meiosis
Genes: unit of hereditary, made up of DNA
Traits: specific characteristic of an organism
 
        
                    
             
        
        
        
The rock cycle is a basic concept in geology that describes the time-consuming transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous. Each of the types of rocks is altered or destroyed when it is forced out of its equilibrium conditions.
        
             
        
        
        
Organisms are composed of cells, they use energy, they grow, and they can reproduce and also living things adapt to their enviorment.
Viruses do not grow, and they cannot reproduce independently. They use host cells to reproduce.