DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?
A) The purines would be separated from the deoxyribose sugars.
B) The pyrimidines would be separated from the deoxyribose sugars.
C) All bases would be separated from the deoxyribose sugars.
D) The two strands of the double helix would separate.
E) The phosphodiester bonds between deoxyribose sugars would be broken.
Answer:
E) The phosphodiester bonds between deoxyribose sugars would be broken.
Explanation:
The purines and pyrimidines of two DNA strands of a DNA duplex are held together by hydrogen bonds. Hydrogen bonds are not covalent bonds. The enzyme DNAase targets the phosphodiester bonds. These are the covalent bonds that join two deoxyribonucleotides of a DNA strand together. therefore, when a DNA is subjected to digestion with DNAase enzyme, the phosphodiester bonds will be broken that hold the pentose sugars of two nucleotides by a phosphate group.
Answer:
Sensory transduction
Explanation:
The sensory process involves many steps to send the signals from the receptor to the brain.
In this, the step that is involved in the conversion of the physical energy into the electrical signal at the sensory receptor (in the given case mechanoreceptors) is known as the Sensory transduction.
When the mechanoreceptors get stimulus by the physical force, it opens the mechanical gate of the dendrites which allows the influx of the positive ions. The influx of the positive ions causes depolarization of the membrane which initiates the action potential which is then transmitted to the brain.
Thus, Sensory transduction is the correct answer.
Answer:
Directional selection
Explanation:
Directional selection is a type of natural selection that favors one extreme phenotype of a genetic trait due to its survival and reproductive advantage to the individuals over another extreme phenotype and the intermediate phenotype.
In the given example, the thick-leaved plants are better adapted to a drier climate due to reduced water loss. Directional selection favored the plants with thick leaves which in turn produced more progeny. Over the generations, the population evolved into the one having more number of thick-leaved plants.
The factors that determines the rate of diffusion in the biological system include: temperature, size of the particles, diffusion distance and concentration gradients. Of all these factors, the most important one is the TEMPERATURE.
The relationship between temperature and the rate of diffusion is a direct one, that is, the higher the temperature the higher the rate of diffusion and vice versa. At high temperature the molecules in the particles move faster because they have higher amount of energy.
