Answer:
Experimental groups: type of dogs
Dependent variable: hearth rate
Independent variable: the amount of caffeine
Explanation:
The dependent variable is the variable being measured or tested in a given study, while the independent variable isn't changed by the other variables. In this case, the heart rate is dependent on the amount of caffeine, which is then the independent variable. The experimental groups are the groups exposed to the independent variable.
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.
C. A new source of freshwater
Explanation:
The situation that would most likely increase the carrying capacity for humans in a certain region is the availability of new sources of freshwater.
In ecological terms, the carrying capacity of a place is the the number of people, animals, or crops which a region can support without environmental degradation.
- A new source of freshwater provides new resources for the ecosystem.
- In the freshwater, more fishes are available, more plants can grow around and a lot of biological activities can progress.
- Water is essential for life.
- Fresh water sources are incentives for choosing to live in a place or not.
- A fresh water source increases the carrying capacity for humans in a certain region.
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Population changes brainly.com/question/2375366
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Answer:
a. autotriploid of species A: 63 chromosomes
b. autotetraploid of species B: 96 chromosomes
c. allotriploid from species A and B: 1) 66 chromosomes and 2) 69 chromosomes
Explanation:
<u>For a.</u>
this species will have 3 haploid sets of chromosomes ('tri' means 3)
one haploid set = 21
21 × 3 = 63 chromosomes
<u>For b.</u>
this species will have 4 haploid sets of chromosomes ('tetra' means 4)
one haploid set = 24
24 × 4 = 96 chromosomes
<u>For c.</u>
there are two ways to do this:
1) two sets of chromosomes from species A and one from species B
42 + 24 = 66 chromosomes
2) one set of chromosomes from species A and two from species B
21 + 48 = 69 chromosomes
Hope that answers the question, have a great day!
