Amutant version of mouse-ear cress (arabidopsis thaliana) has been engineered to convert it from a long-day plant to a short-day plant. what is responsible for triggering the development of flowers in this plant?

day length decreases back to a critical length, causing an appropriate decrease in pr : pfr ratio and increased expression of genes required for flowering.

day length increases to a critical length, causing an appropriate increase in pfr : pr ratio and increased expression of genes required for flowering.

day length decreases back to a critical length, causing an appropriate decrease in pfr : pr ratio and increased expression of genes required for flowering.

day length increases to a critical length, causing an appropriate increase in pr : pfr ratio and increased expression of genes required for flowering

option c.

Explanation:

Long Day Plants- The plants which flower when the day length is longer than the critical day length(Plants physiological events such as seed germination, initiation of flowering, asexual reproduction are triggered by a photo-period of specific length, this specific period length is critical day length). Examples- Spinach, wheat and spring barley.

Short Day Plants- The plants which flower when the day length is less than the critical day length. Examples- Soybean and tobacco.

So, In short day plants a flash of red light (Pr) during dark period prevents flowering, and the effect is reversed by the flash of far-red light (Pfr). In case of long day plants a flash of red light (Pr) during night break promotes flowering and a flash of far-red light (Pfr) during dark period prevents flowering.

hence option c.

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.