Answer:
a dominant mutation
Explanation:
A monohybrid testcross is a cross-breeding experiment used to determine if an individual exhibiting a dominant phenotype is homo-zygous dominant or heterozygous for a particular phenotypic trait (in this case, wing length). In a monohybrid testcross, a 1:1 phenotypic ratio shows that the dominant parental phenotype was a heterozygote for a single gene that has complete dominance. Moreover, a 3:1 ratio in the F2 is expected of a cross between heterozygous F1 individuals, which means that 75% of individuals with short wings have the dominant allele that masks the expression of the long-wing trait (i.e. the recessive allele).
Answer:
Option-D, a segment of DNA
Explanation:
A gene represents the particular segment of DNA which contains the instruction for the trait of an organism. The nucleotide sequence present in the segment provides the instruction in the form of codons.
The gene is present in the form of its alternative form called alleles which are located on the chromosomes at locus. The alleles represent the variants of the gene and therefore controls the two variety of a single trait.
Thus, Option-D is correct.
We first have to understand what a vascular system is. A vascular system consists of the water-carrying tube(xylem) and food-carrying tube(phloem). These 2 tubes are very essential for plants to survive. The xylem transports water to the leaves thru the stem to nourish the leaves so as to make food. The word equation is : Water + Carbon dioxide ----> Glucose + Oxygen. The phloem on the other hand transports the food from the leaves that creates them amd sent them to all parts of the plant. It is often a misconception that food is only sent to the fruits. The plant receives nutrition from the food that is made by the leaves. Overall the vascular system plays a very importamt roles in the survival of the plant.
To put it simple, think of the vascular system of a plant like the circulatory system of a human. Without the circulatory system, the human is unable to receive oxygen for breathing and remove carbon dioxide which is acidic in nature and pose a threat to the human body.
