The gene src normally is activated by extracellular signals called growth factors. when the growth factors are present, src instructs the cell to divide. a mutant form of src is found in many cancer tumors. the mutant form of src is active in the absence of growth factors. the mutated src is a
a. tumor suppressor gene
b. oncogene
c. cancer gene
d. proto-oncogene

B. Oncogene

Explanation:

A gene that makes the body cells to divide in an uncontrolled manner is called an oncogene. An oncogene is responsible for the development of tumors due to disturbed regulation of cell division. The gene src makes the cells to enter the process of cell division in response to the growth factors.

However, the mutant src gene does not require the presence of growth factors and signals the cells to enter the process of cell division even in the absence of the growth factors. Since the mutant src gene causes uncontrolled cell division, it represents an oncogene.

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).