Surface area is an important factor in limiting cell growth because
a. the cell can burst if the membrane becomes too large.
b. materials cannot enter the cell if the surface is too large.
c. the cell may become too large to take in enough food and to remove enough wastes.
d. waste products cannot leave the cell if the cell is too small.
Answer:
c. the cell may become too large to take in enough food and to remove enough wastes.
Explanation:
The exchange of substances with surroundings is done by cells by the process of diffusion. The rate of diffusion of substances requires the presence of a higher surface area than volume. As the cells become larger, their surface area is reduced with respect to the volume. Therefore, larger cells can not support the diffusion of substances in and out as required for its proper functioning. If cells are allowed to grow continuously, they will not be able to intake the requires materials such as food and to release the waste outside.
The greek root-word Bios means life
1.Magnification is the ability of optical instruments, such as a telescope or a microscope, to make an object bigger while resolution is the ability of optical instruments to produce images that are clearer, finer, and sharper.
2.Resolution is the power of an optical instrument to capture and produce more details of an image while magnification is the power of an instrument to create and produce a much larger image of an object.
3.Resolution can be expressed in arcsec or seconds while magnification can be expressed by a whole number and the letter “X.”
4.Although both are dependent upon each other, a high magnification does not always guarantee a high resolution.
5.Magnification allows us to see small objects, especially those that are not visible to the naked eye, while resolution allows us to see these objects more clearly and with more details.
Answer:
In eukaryotic cells you find core and proximal promoters.
Promotors are specific DNA sequences where transcription factors (proteins) and RNA polymerase binds to initiate transcription. Promotors are located upstream the coding sequence
Core promoters are where RNA polymersae binds and proximal promoters are where transcription factors bind.
Enhancer elements are DNA sequences where transcription factors (proteins) bind to increase the rate of expresion of an specific gene. Enhancers can be located either upstream, downstream or thousands of nucleotids away from the of the coding region.
Explanation:
Promoters and enhancer are key elements for controling gene regulation. Transcription begins when chromatin rearranges from a condensed state to a accesible state, this allow to transcrition factors and RNA polymerase to bind specif DNA sequences (promotors). Proteins bind to enhancers , this complex develops a DNA loop, so that the protein that is bound to the enhancer interacts with the RNA polymersase. When this interaction is made, the activity of the RNA polymerase is increased.
Explanation:
an individual animal, plant, or single-celled life form.
