Answer:
Absorption and secretion would be impossible within the digestive tract.
Explanation:
Epithelium is one of the tissues found in humans. It is classified as either simple or stratified depending on the number of cell layers. Simple epithelial tissues have one layer of cells while stratified have many layers of cells. Based on the shape, epithelial tissues can either be squamous, columnar or cuboidal.
Due to the single-layer of the simple epithelial tissues, they line the walls of secretory or absorptive organs e.g organs of digestive tract. The stratified epithelium is majorly for protective function due to the number of cell layers it possess and not a good type of epithelium for locations where absorption and secretion of substances is common e.g digestive tract.
Hence, if a genetic mutation causes a person's digestive tract to have stratified columnar epithelium instead of simple columnar epithelium, ABSORPTION AND SECRETION of chemical substances, which is a key feature of organs (stomach, intestine) that make up digestive tracts, will be impossible.
Answer:
The type of mutation responsible for changing a base in the mRNA strand, without changing the coding aminoacid or protein, is called a <u>silent</u> mutation.
Explanation:
In a silent mutation occurs the change of a nitrogenous base in one of the codons that encodes an aminoacid, without changing the aminoacid or altering the structure or function of the protein to be synthesized.
In this type of mutations the change of the base does not mean the change of the aminoacid, because some aminoacids can be coded with more than one codon. In the case of Leucine, the codons that encode it are CUU, CUC, CUG or CUA, so even if a base changes, the final protein will be the correct one.
For the other options:
- <u><em>Missense</em></u><em>: the change of the base in the DNA chain implies the change of the codon in the mRNA and of the encoded aminoacid, in that way a structural and functional alteration of the synthesized protein occurs. </em>
- <u><em>Nonsense</em></u><em>: the change in the nitrogenous base in the DNA leads to the coding of a termination codon, so that the protein is ultimately incomplete.</em>
- <u><em>Insertion</em></u><em>: in this case there is the addition of more nitrogenous bases to the DNA chain, with respect to the original one.</em>
Food web provides a better model of an ecosystem and model of many different consumers
Answer:
All multicellular organisms use cell division for growth and the maintenance and repair of cells and tissues. Cell division is tightly regulated because the occasional failure of regulation can have life-threatening consequences.
Answer:
Look at my explanation (I have notes on this)
Explanation:
•They divided people off based on their purity
•Government: they were ruled by kings
•Their writing contained 400 symbols, both pictographs and phonetic characters
•Their cities had high walls and laid out in grid system (Citadel was a watch tower and one of the major buildings)
•They had polytheistic religion called Hinduism
