Answer:
A. Mendel observed green and yellow pea pods in a 3:1 ratio because the F1 generation was heterozygous.
Explanation:
The two true breeding plants in the parental population were homozygous (that is what true breeding means). Therefore, their cross would lead to all heterozygous offspring (see attached punnet square). Green is the dominant characteristic, so all F1 plants had a green phenotype, but Gg genotype.
The F1 cross would therefore be Gg x Gg. See attached punnet square.
The genotypes in the F2 generation are 1 GG: 2 Gg: 1 gg 1
Therefore, the phenotypic ratio is 3 green pea pods (Gg or GG): 1 yellow (gg)
<span>Parents can pass on chromosomes to their children that are different than their own when the new gene combinations are created by crossing over. The exchange of genetic material between homologous chromosomes is known as crossing over which occurs in meiosis. When homologous chromosomes pair up and exchange different segments of the genetic material. As the result, a new combination of genes will be formed. If there was not crossing over, all genes on a chromosome would be inherited together.</span>

yeh American server h yha koi tumahri hindi nhi samjhega-,-..xD
Let us look at the what, why and how of studying extreme places like the deep earth and the deep space. Scientists need to figure out as to 'what' they want to look at such places, be it a new exotic creature or bio-genesis (birth of life). Unless there are several testable hypothesis constructed, such a study cannot begin. The 'why' aspect deals with the purpose of such research and expeditions. Is it of any use to the humans, or will it improve our current understanding of a phenomenon? The 'how' aspect deals with the technology and the economic assistance that can help in undertaking such a research. All these are the challenges that needed to be thoroughly considered to make such a research or expedition possible.