Answer:
The option 'All cells contain a nucleus' is not a part of the cell theory.
Explanation:
The cell theory proposed by scientists illustrates that every organism whether prokaryotic or eukaryotic is made up of a cell or different kinds of cells. It also that explains that cells are made from living things. According to the cell theory, cells are termed as the basic unit of life, without which life is not possible.
The cell theory does not claim that every cell must have a nucleus because many cells like cells of prokaryotes lack nucleus. Their genetic material is dispersed in the cytoplasm.
Answer: B (Color blindness)
Explanation:
Typical red-green color blindness in human patients is caused by mutations on genes located in the X chromosome. These mutations act in a recessive manner. Since females have two X chromosomes, the presence of a mutation in a single one of them does not normally result in color blindness. Males, in contrast, have a single X chromosome and therefore the presence of a mutation is likely to cause the disease.
About the other options: Down‘s syndrome is a numerical chromosomal anomaly, not related to sex. Human blood type is a codominant trait. Finally, tail length in dogs is a polygenic trait not amenable to classic Mendelian analysis.
Answer:
4 percent (4%)
Explanation:
A single crossover occurs between two (non-sister) chromatids belonging to homologous chromosomes. In this case, 16 percent of the meioses have a single crossover, thereby it will produce 8 percent of the chromosomes with the original (parental) combination in the progeny and the remaining 8 percent should be recombinants. From this result, it is reasonable to conclude that half of these recombinants should be 'Br' (and the other remaining 4 percent should be recombinants 'bR'), and therefore the answer is 4 percent (4%).
Because carbon dioxide is a GREENHOUSE GAS, it can trap the sun's heat in the atmosphere. Because the factory is made of concrete, it may deplete groundwater levels overtime by not allowing water to INFILTRATE.
Greenhouse gases trap the sun's heat and this is how we can feel it. Without greenhouse gases the earth's average temperature would be 30 degrees less. Other greenhouse gases include water vapor and methane. Increases in the levels of Greenhouse gasses are responsible for present day global warming.
Infiltration is the process by which water enters the soil and eventually becomes part of the groundwater.
