Answer:
Explanation:
Staining is done for onion cells to visualize the cytoplasm of yellow and white onions because they are not pigmented. The staining of human cheek cells with methylene blue is necessary to stain the nucleus to get clear image of it under microscope because methylene blue binds to negative charge nucleic acids
While for leaf epidermal cells smears, staining is not necessary as they are visible under light microscope without staining and they also have pigmented materials inside them such as chlorophyll chloroplast. The cork cell is a non-living and have a cell wall whose structure is visible under light microscope.
Answer:
3. An Apple Turning Brown
Explanation:
When an apple is cut (or bruised), oxygen is introduced into the injured plant tissue. When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors to brown-colored secondary products.
Answer:
0
Explanation:
as long as one parent is pure for a dominant allele it will be 0 for the other trait
The answer should be "a" but it needs to read the promoter region of a gene is bound to the enzyme RNA polymerase, positioning the enzyme on the correct DNA strand.
In the process of transcription, an enzyme called RNA polymerase recognizes and binds to a DNA nucleotide sequence just before the beginning of the gene. This recognition site, called a promoter, positions RNA polymerase properly on the correct DNA strand and points it in the right direction.
The DNA strands then separate over a short distance and the polymerase moves into the gene and as it moves, it creates a new chain by linking together individual ribonucleotides existing free in the cell, This new chain or strand is called messenger RNA.
