<span>In order to lower the PH to an appropriate level so that garden plants thrive,
the gardener should add a natural acid like pine needles or humus.
To add a base like calcium carbonate or limestone. Acids have a PH which is less than 7.
If a base is added to an acid, the PH is raised. Adding humus will decrease the PH as it is also acidic. Adding fertilizer may help the plants, but it won't change the PH neither watering will.</span>
Answer:
The Restriction Fragment Length Polymorphism (RFLP) and the Polymerase Chain Reaction (PCR) are techniques used in molecular biology to identify polymorphisms in DNA samples obtained from different species, organisms, varieties, strains, etc. In the case of RFLP, the DNA is digested with restriction enzymes, so the resulting fragments have different lengths, while in the PCR technique the DNA fragments are obtained by successive amplification cycles and they have the same length.
Limiting factors will affect a specific species that lives in an area for example a<span>ll </span>living<span> things need food, water, shelter and space to survive if i built a dam on a river that would be supplying water to the forest to the wild animals this will make a shortage of water for the animals and they could die from this shortage </span>
What is Sickle cell anemia?
Sickle cell is an autosomal recessive trait of humans that arises through mutation in normal gene. The gene for this trait is found in recessive form and you need two copies of the gene - one from father and one from mother- to have the trait expressed. If the trait is expressed it causes a disease called sickle cell anemia.
People with the sickle cell anemia disease have red blood cells of crescent or sickle shape. The red blood cells of this shape can cause many complications in body. They get stuck in blood vessels and cause pain. They also die quickly and make a person anemic (pale).
Probability to have a child with sickle cell anemia:
If a mother is normal but a father is carrier for the trait, then the situation will be as:
Here N indicate normal allele, S indicate allele for sickle cell anemia.
Mother ˣ Father
NN NS
Gametes: N N N S
Offspring: NN NS NN NS
50% : Normal
50% : Carrier
0% : Sickle cell anemia
It means that 50 % kids will be normal and 50% will be carrier for the trait and none of the offspring will have disease Sickle cell anemia.
However, those who are carriers can carry the disease to the next offspring if they are married to a carrier or a person with sickle cell anemia.
Answer:
The correct answer is: Electrical impulses in the heart cause the muscles to contract.
Explanation:
The heart contracts thanks to a series of electrical impulses that travel through the muscles of this organ. The electrical impulse begins in the SA (sinoatrial) node and is transmitted to the muscles that conform the left and the right atria to produce their contraction which will make the atria pump the blood to the ventricles. When the electrical impulse reaches the AV node and then the Bundle of His, this information will transmit to both ventricles and will produce their contraction as well.
The only muscle tissue capable of stimulating their own contractions is the muscle in the heart, the myocardium, thanks to the existence of "pacemaker cells" that are located in the SA node.
The waves in the ECG represent the depolarization of the atria, depolarization of the ventricles, and repolarization of the ventricles.
