DNA (or deoxyribonucleic acid) is the molecule that carries the genetic information in all cellular forms of life and some viruses. Source-
DNA, Genes and Chromosomes — University of Leicester
www2.le.ac.uk/projects/vgec/highereducation/topics/dna-genes-chromosomes
Answer:
A = Activator
B = Effector
Explanation:
An activator is a protein which typically binds to a short (50–1500 bp) region of DNA which might be located either upstream (mainly) or downstream of a gene so as to cause increased transcription. This particular region of DNA is known as enhancer and activator is also known as transcription factor. Activator is a trans-acting factor which binds to the cis-acting factor which is enhancer so as to enhance transcriptional expression.
But another protein named as effector may restrict activator from binding to the enhancer leading to a decrease in transcriptional expression by binding to the activator allosterically. Allosteric binding of effector to the activator causes conformational change in activator so it can no longer bind the enhancer.
Answer:
hydrogen bond
Explanation:
by weak electrical attraction between two polar molecule hydrogen bond is developed between them
the example is water molecule in case of water two water molecules are attracted toward each other by strong hydrogen bond which is developed between highly electronegative oxygen of one water and electropositive hydrogen of another water molecule
Newton’s first law of motion? May be wrong