Answer:columnar describes cell shape.
Simple describe the number of layers
Explanation: epithelial tissues are one of the four major tissues of the body.the others being nervous, muscular, connective tissues.
Epithelial tissues are made up of thin cells that cover the external and internal surface of the body.
The cells may form one layer or more and they occur in several shapes.if they form one layer ,it is called simple.if they form several layers,it is called stratified.
Some are called pseudo-stratified because the cells occur with varying lengths and give the impression of stratified but they are actually made up of one layer.
Simple columnar epithelium is a single layer of tall, closely packed cells. They possess cellular extensions ,such as microvilli in the small intestine, or the cilia in the female reproductive tract.
Answer:
Urey and miller cooked a "primordial soup" with Hadean gases, water and electricity to make <u>glucose</u>, <u>acetic acid</u>, <u>amino acids</u> and <u>lipids</u>.
Explanation:
In the Miller-Urey experiment, the aim was to reproduce the conditions of the earth before the existence of life, with the objective of demonstrating the formation of organic matter from inorganic molecules.
The scientists took water and gases present in the Hadean eon —previous to the existence of life— such as methane, carbon dioxide, hydrogen, nitrogen and even ammonia, the primordial soup. This mixture was subjected to electrical discharges, inside closed containers.
The results were some organic molecules, including glucose, acetic acid, amino acids and fatty acids. In these results the presence of macromolecules, such as proteins or nucleic acids, is not appreciated, however it was a significant contribution to the knowledge of the origin of life on earth.
Answer: A. Extirpation
Explanation:
The term extirpation is also known as local extinction. It is situation whereby a particular species ceased to exist in an environment where it was once found, though it's existence is still observed elsewhere.
Extirpation maybe as a result of unfavorable environmental and human factors such as hunting, food scarcity and climate variation.
Repressor slows down transcription.
RNA Polymerase enzyme transcribes mRNA from DNA.
Explanation:
Promoters are the 100 to 900 bps long sequence of DNA, that helps in the initiation of transcription. The transcription gets slow down as repressor bind to the promoter region hampering the attachment of RNA Polymerase enzyme which is responsible for transcription.
The process of transcription is the conversion of DNA into mRNA as told in the central dogma of molecular biology. Enzyme responsible for transcription is RNA polymerase. It is the first phase of gene expression, where DNA strand is copied into mRNA called a primary transcript.
Explanation:
In digestion, the liver is involved in processing the nutrients that are absorbed from the small intestine. It helps in the digestion of fat.
On the other hand, the liver maintains homeostasis by serving an important function in the excretory system.
