Nondisjunction is the failure of one or more pairs of homologous chromosomes or sister chromatic.
Answer:
This question lacks options, the options are:
A. All 270 tall plants were heterozygous
B. All 270 tall plants were homzygous.
C. Only 90 plants were homzygous.
D. All dwarf plants were homzygous.
The answer is D.
Explanation:
This question involves a single gene coding for height in pea plants. The allele for tallness (T) is dominant over that of dwarfness (t). This means that a dwarf plant can only be homzygous recessive (tt) while a tall plant can either be homzygous (TT) or heterozygous (Tt).
According to the question, two tall heterozygous pea plants were crossed i.e. Tt × Tt. Based on this cross, a phenotypic ratio of 3:1 is expected, which is in accordance with the 270 tall plants and 90 dwarf plants (360 total) that was obtained in the cross. Since dwarfism in pea plants is a recessive trait, this means that all the dwarf plants produced in this cross (90) were homzygous (tt).
Fossils show evidence of descent with modification
The science of Cancer Biology focuses on the study of the different mechanisms and fundamental process of cell growth, the transformation of normal to cancer cells, and the metastasis or spread of these cancer cells to other parts of the body.
As such, it includes the study of how tumor cells develop and grow. It also includes studying how the immune system responds to cancer cells, thus including macrophages and their response to the presence of pathogens and cancer cells. Underlying all these is the inclusion of a study on protein synthesis as it is the process where biological cells build and create new specific proteins in the body.
