A cell does not want to waste energy synthesizing the amino acid arginine if arginine is present in its diet. Therefore, when arginine is present, it activates a repressor protein to prevent transcription of genes that code for enzyme to make arginine. This is an example of what type of regulation?

#Question id: 27581

#XL - U Food Technology

EPH and DHA types lipids are mostly found in

#Question id: 14092

#XL - R Botany

#Question id: 5686

#XL - R Botany

Following statements are regarding to double fertilization in angiosperms.

A. One sperm cell fuses with the egg cell to produce the zygote that will develop into the new embryonic plant.

B. The second sperm cell fuses with the usually binucleate central cell, giving rise to the

endosperm, the tissue that nourishes the developing embryo. This second event is not “true” fertilization in the sense of male and female gametes undergoing fusion.

C. The second sperm cell fuses with the usually binucleate central cell, giving rise to the

endosperm, the tissue that nourishes the developing embryo. This second event is “true” fertilization in the sense of male and female gametes undergoing fusion.

D. During fertilization in angiosperm, when the sperm cells are released, the egg undergoes a flux of Ca2+. Then, chemicals released from the egg appear to make the sperm competent for cell fusion.

Which of the following statements are true?

#Question id: 374

#XL - Q Biochemistry

The pH of a sample of blood is 7.4, while gastric juice is pH 1.4.  The blood sample has:

#Question id: 4567

#XL - S Microbiology

Charles Darwin was the first person to propose