The Cells.. Help on 3 questions?

Question

desctribe how the nucleus controls a cell's activites.

Describe the structure and function of a gene.

What effect does increasing the size of a cell have on its surface to-volume ratio?

Answer 1

The nucleus regulates all cell activity. It does this by controlling the enzymes present. The chromatin is composed of DNA. DNA contains the information for the production of proteins. This information is encoded in the 4 DNA bases. Adenine, thymine, cytocine, and guanine. The specific sequence of these bases tells the cell what order to put the amino acids.
There are three processes that enable the cell to manufacture protein:
Replication allows the nucleus to make exact copies of its DNA
Transcription allows the cell to make RNA working copies of its DNA
In translation the Messenger RNA is used to line up amino acids into a protein molecule






gene is a locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions and/or other functional sequence regions.[1] Genes interact with each other to influence physical development and behavior. Genes consist of a long strand of DNA (RNA in some viruses) that contains a promoter, which controls the activity of a gene, and a coding sequence, which determines what the gene produces. When a gene is active, the coding sequence is copied in a process called transcription, producing an RNA copy of the gene's information. This RNA can then direct the synthesis of proteins via the genetic code. However, RNAs can also be used directly, for example as part of the ribosome. These molecules resulting from gene expression, whether RNA or protein, are known as gene products.

Most genes contain non-coding regions that do not code for the gene products, but regulate gene expression. The genes of eukaryotic organisms can contain non-coding regions called introns that are removed from the messenger RNA in a process known as splicing. The regions that actually encode the gene product, which can be much smaller than the introns, are known as exons. One single gene can lead to the synthesis of multiple proteins through the different arrangements of exons produced by alternative splicings.

The total complement of genes in an organism or cell is known as its genome. The genome size of an organism is loosely dependent on its complexity; prokaryotes such as bacteria and archaea have generally smaller genomes, both in number of base pairs and number of genes, than even single-celled eukaryotes. However, the largest known genome belongs to the single-celled amoeba Amoeba dubia, with over 6 billion base pairs.[2] The estimated number of genes in the human genome has been repeatedly revised downward since the completion of the Human Genome Project; current estimates place the human genome at just under 3 billion base pairs and about 20,000-25,000 genes.[3] The gene density of a genome is a measure of the number of genes per million base pairs (called a megabase, Mb); prokaryotic genomes have much higher gene densities than eukaryotes

Answer 2

A nucleus controls a cell's activities by directing the production of the necessary proteins. DNA has the code for building proteins. Then the proteins handle everything else.

A gene is the set of instructions for making a particular protein. A gene is made of DNA - it is one section of the DNA in a chromosome.

Increasing the size of a cell REDUCES the surface area to volume ratio. The surface area does not increase as quickly as the volume does, so a bigger cell has too much volume for the plasma membrane support through active and passive transport.

Answer 3

a million.B 2.a three.A 2. with the intention to go molecules in you kidneys, your physique needs potential. The flow of something in a residing organism demands potential, solutions B&C are dumb, and warmth is a byproduct of potential use, that answer is there to trick you. 3. Cells keep potential while the third phosphate group breaks off from an ATP molecule. potential is saved as ADP so once you ruin off the third phosphate from Adenosine TRIphoshate it particularly is going to become Adenosine DIphosphate. B is incorrect on account which you ruin down sugars once you prefer potential D. why might you launch ions with the intention to keep potential? C. is there to trick you because of the fact all of us understand that ADP is used to keep potential even nevertheless in case you bond a third phosphate to ADP it particularly is going to become ATP with the aid of ATP synthesis. a million. Which sugar is a factor of ADP? ribose duh! ADP includes the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine.