Explanation:
<h3>for example:- </h3>
If a mutation led to brighter feather colouring in birds, the brighter feathers may allow those individuals with the mutation to reproduce more frequently, because they are seen as being more attractive and a desirable mate.
ALWAYS use both hands when picking the microscope up and moving it from one place to another. 3. When focusing on a slide, ALWAYS start with either the 4X or 10X objective. Once you have the object in focus, then switch to the next higher power objective.
Answer:
1) A, C and D
2) D
Explanation:
The normal hemoglobin is made up of heme and globin. The protein, globin is in turn made up of four polypeptide chains which include two alpha and two beta chains.
The gene gene responsible for the creation of the beta globin chain is located on the short arm of chromosome eleven. It is called the HBB gene. Many mutations occur on the HBB gene and a mutation on this gene produces abnormal hemoglobin like HBS, hbc, and hbe. HBs causes sickle cell anemia.
In sickle cell anemia, there is an alteration of the genetic code, leading to the substitution of a single amino acid where glutamic acid is replaced by valine in the sixth position of the beta chain.
In the mRNA, the change converts a glutamic acid codon(GAG or GAA) to a valine codon(GUA, GUC, GUU or GUG).
Sickle cell anemia is caused by a transversion that leads to a missense mutation.
Answer: (C) Mesenchymal
Explanation:
The intramembranous ossification is the process when the neural crest are derived from the mesenchymal cells that are differentiate into the specialized bone formed cells which is known as osteoblasts. These osteoblast form a group into the cluster and then formed a center ossification.
The intramembranous ossification start begins with the help of flat bone, cranial bone that are present in our face. This process basically begin the mesenchymal cells start differentiate into some specialized form of the cells.
Therefore, Option (C) is correct.
Answer:
See explanation.
Explanation:
Radioactive dating, also known as carbon-14 dating, has some limitations. This technique can theoretically provide the age of something that was once alive. This method does not work with inorganic items such as tools made of stone or pottery that is made with something inorganic such as ceramic materials.
One limitation of this type of dating is that the amount of carbon-14 is less and less the older something is. This means that there is less and less to measure. This usually means there are limits of about 60,000 years with respect to the age that can be measured by this method.
Another limitation has to do with contamination with other items. For example, if there are items that might affect the carbon-14 dating in the sample, the item might measure as being much older than it really is. Substances that might contaminate the sample include coal. There might be other items that include older sources of carbon.