Answer:
Independent variable: different amounts of second-hand smoke
Explanation:
The independent variable in an experiment is the variable that the experimenter changes or manipulates in order to bring about a measurable response.
In this question, a test is being carried out to determine the health effects of different amounts of second-hand smoke on one-year-old hamsters. Based on this, the independent/manipulated variable is the DIFFERENT AMOUNTS OF SECOND-HAND SMOKE because it is the variable being changed.
1. A transgenic organism expresses DNA that has been derived from another species. These organisms have altered genomes and are generated in the laboratory for the purposes of research, for example, the "knock-out" mice are tansgenic mice with a particular gene of interest disabled.
2. Recombinant DNA is the DNA that has been altered to contain genes, or portions of genes, from different organisms. The DNA molecules are formed in the lab using recombination methods to bring together genetic material from multiple sources and therefore creating sequences that are not found in the genome.
3. Restriction enzymes are found naturally in bacteria and they cut DNA at specific nucleotide sequences. These enzymes are also called restriction endonucleases, they cleave DNA into fragments at or near specific recognition sites called restriction sites. They are found in bacteria and archaea and they serve to provide a defense mechanism against invading viruses.
4. Biotechnology is the use or alteration of organisms, cells, or biological molecules to produce food, drugs, or other goods. Living systems and organisms are used to make or develop products. Biotechnology enhances cellular and biomolecular processes to develop technologies and product for the purposes of improving life and health.
5. Polymerase chain reaction is a technique that is used to quickly synthesize billions of copiies of a specific segment of DNA. It is a quick and a very efficient way to generate many copies of DNA. The process is applicable when there are small quantities of DNA to analyze. The events of PCR involves; separation of DNA strands, addition of primers, use of DNA polymerase to produce second strand of DNA.
6. In the process known as transformation, bacteria take up pieces of DNA from the surroundings. Bacterial transformation results from the uptake of naked DNA (DNA without associated cells or proteins). Transformation may also occur naturally in some species of bacteria.
Answer:
On the deep ocean floor
Explanation:
This is because it is the lowest layer of the ocean where little or no light penetrate. In this floor, there are abundance of organic matter which the fish majorly feed and that is why they abundant there. The temperature in deep ocean floor is moderate and it's okay for their survival. The humidity also is moderate and that is why they live there.
Answer: Contractility of the left ventricle myocardium ensures that blood will have enough force to reach the rest of the body.
Explanation: Frank Starling Law....Cardiac output=heart rate x stroke volume.
The urethra is the tube that conducts the flow of urine in both sexes from the interior of the body to the external world. In males, semen also travels through the urethra during sexual intercourse. The urethra connects the bladder, the collection site for urine to the outside world. In males, the urethra is 8 inches long, while in females, the urethra is only 2 inches long. So the primary difference is one of length. Another difference would be the path the urine takes getting from the bladder to the external world. In females, the path is more direct, while in males, the path is more curving. This curved path makes catheterization of males more difficult than females. Due to the short length of the urethra in females, infection can be a problem. Urethritis is an inflammation of the urethra common in females. The passing of kidney stones is another affliction that strikes both sexes in the area of the urethra.
