The answer of this question is False
Answer:
the pH
Explanation:
The condition that should not be kept the same in each of the five test tubes is the pH.
Since <u>the aim of the experiment is to investigate the effect of pH on the activity of the lipase enzyme</u>, the pH is, therefore, the <em>independent variable</em>. Thus, it must be controlled or varied in all the test tubes in order to see its effect on the activity of the enzyme, which, in this case, would be the dependent variable.
Answer:
a. The directionality of the complementary strand is antiparallel. The double-stranded DNA is antiparallel comprising two strands, which run alongside each other, however, point in reverse directions. In a double-stranded molecule of DNA, the 5 prime ends of one strand align with the 3 prime ends of the other strand, and vice versa.
b. The mediation of base pairing is done by non-covalent hydrogen bonds. It is reversible, that is, the strands can separate and can come combined again without any chemical modification.
The specificity of base pairing is illustrated by hydrogen bonds that is, the first strand produces hydrogen bonds only with a particular base in the second strand, and these two bases produce a base-pair.
c. The interaction or association of non-covalent type, that is, hydrophobic interaction and hydrogen bonding. Collectively, they both are strong. In the process, one base associate with the other base on the complementary strand.
d. The phosphate backbone possesses the tendency to associate with water on the outside of the molecule, and this is favorable chemically as both the strands are held together by hydrogen bond and hydrophobic interaction.
The polar molecules of sugar can produce hydrogen bonds with the surrounding molecules of water. The negatively charged phosphate group associate with the positively charged ions. The nonpolar nitrogen bases are found within the molecule and associate favorably through stacking interactions.
D) no change in cardiac output, increased heart rate, decreased stroke volume occurs after blood donation
Explanation:
When a person donates blood, there is a slight loss of blood volume or hypovolemia. This triggers the baroreceptors of the blood; although does not trigger the osmoreceptor.
The baroreceptor responses are according to the arterial pressure which rises momentarily and results in increased sympathetic activity with decreased vagal activity.
These changes will lead to vasoconstriction, reduced stroke volume, increased heart rate or tachycardia which helps to maintain the cardiac output.
The soreness at the venepuncture site on the skin is due to bruising which is common after any needleprick. applying cold pack, elevating and resting the arm.
In order to compensate for the fluid volume loss and avoid dehydration, one must take plenty of fluids before and after blood donation.
1.High yield modern agriculture refers to the practice of breeding genetically modified crops or using fertilizer to increase the production yield of planted crops. Two advantage of high yield modern agriculture are:
1. Production of large quantities of planted crops.
2. Ability to select and breed plants with superior qualities.
2. Agriculture have some negative influence on the environment, the major harmful environmental impacts of agriculture are:
a. Habitat loss: Agricultural practices present great danger to species and ecosystem. This is because, farmed areas serve as habitats for different types of wild plants and animals. Farming the areas makes these living organisms to lose their habitats and these throw the ecosystem into imbalance.
b. Soil erosion and degradation: When natural vegetation are converted into agricultural lands, the breaking up of the soil leads to erosion, which wash away the top soil and the nutrients that are embedded in it.
c. Pollution: The chemicals that are used during farming operations, such as fertilizers, pesticides, etc. cause pollution of the air and the surrounding waters.
3. Soil erosion is the process by which the top layers of soils are carried away by agents such as wind and water. The biggest negative effect of soil erosion is the loss of top soil. The top soil is the part of the soil that contain most of the nutrients that plants use to grow. When this part of the soil is lost, the soil usually becomes non fertile. Soil erosion can also lead to water pollution. When soils are eroded from the farm lands and carried to the surrounding waters, the waters will be polluted by the chemicals such as pesticides, herbicides and fertilizers, which are had been used on the soils. This can lead to the death of the animals that are living in the waters.
