Echolocation is also called bio sonar. It is the sonar used by several kinds of animals that <span>enables them to locate and discriminate objects by projecting high-frequency sound waves and listening for echoes as the sound waves reflect off objects. </span>
Dolphins and whales make these sounds at any time and at considerable depths. Sounds vary in volume, wavelength, frequency, and pattern.
The wavelength depends on the speed of
propagation (c).wavelength=c/f The speed of sound in water is c= 1450 m/s.
So, for bottlenose delphins the wavelength is:1450m/s / 110.5 kHz
1450 m/s / 110500 Hz =0.013 m = 0.13 mm
For whales the waveleng42.5 th is:1450m/s / 42.5 kHz =
1450m/s / 42500 Hz= 0.034 m = 0.34 mm
C) DNA
Inside the nucleus, DNA and proteins together form chromosomes.
Answer:
Option B
Explanation:
Flight-or-flight response is a response or physiological reaction towards external stimuli. Systematic desensitization is a methodology to control anxiety during speech. Hence, these two are not relaxation techniques. Transforming novelty into familiarity is also a methodology to remain prepared during a speech by practicing it well. Visualization is a technique that helps our mind to relax by using imagination to reach a relaxed state of mind.
Hence, option B is correct
<span>The determining factor in how well a patient is able to compensate for loss of blood in usually related to how rapidly they are bleeding. The ability or the lack of ability to compensate for blood loss is controlled by a patient's cardiovascular system, but the rate of blood loss is key.</span>
Answer:
The correct answer is: d. REs activity is best preserved by freezing the RE and thawing it out for brief periods of time as needed.
Explanation:
- Restriction enzymes can be defined as endonucleases that can recognize specific nucleotide sequence in a DNA (Deoxyribonucleic acid) sequence and cause breakage of phosphodiester bond in the DNA at the target site. Hence, it has the capacity of cleaving a DNA sequence.
- These are made up of proteins which are required to be present in the accurately folded conformation in order to function.
- Any form of alteration in the three-dimensional structure of the protein induced due to physical, chemical, mechanical or physiological factors can cause denaturation of the protein which in turn can render the protein non-functional.
- Freezing of restriction enzymes (REs) directly without the use of glycerol will cause the movement of water molecules within the proteins as well layering of water molecules on the protein surface.
- At low temperature these water molecules change to ice crystals which can alter the conformation of the protein or can cause breakage of peptide bonds in the proteins by physical force.
- This can cause the protein to get denatured and hence non-functional.
- Hence, it is never advisable to preserve REs by freezing directly without glycerol.
- Glycerol forms a layer around the protein molecules and prevents the protein molecules from coming into direct contact with the water molecules and hence prevents protein denaturation.
