Answer:HIV attacks a specific type of immune system cell in the body. It's known as the CD4 helper cell or T cell. When HIV destroys this cell, it becomes harder for the body to fight off other infections. When HIV is left untreated, even a minor infection such as a cold can be much more severe.
Explanation:
The basic needs of all cells in the body is to have food, oxygen, and have their wastes taken away.
The genetic variation of organisms has three sources they are mutation, gene flow and sexual reproduction.
Explanation:
Genetic variation are caused by mutation , random mating, random fertilization and recombination between homologous chromosomes during meiosis.
It is a variation in alleles and genes, among the populations. There is a genetic variation within the family of closely- related individuals. If it is a neighborhood there are many families and there is also genetic variation among that group.
An exact genetic copy of the parent organism is produced in asexual reproduction. It only introduces the genetic variation into the population if a random mutation in the organism's DNA is passed on to the offspring.
Answer:
c. have changed the behavior of elk.
Explanation:
Wolves were reintroduced into Yellowstone Park in 1995. Prior to this time, they were a major predator in the park. Their reintroduction after a decade resulted in a change in the behavior of the Elk which now had a large population in the park and appeared in large herds.
The Elk's behavior has also changed as they do not move into farther thickets so as not to be attacked by wolves. Also, they no longer move to open fields where they grazed as herds to avoid being preyed upon by lions. Vegetation is now restored due to this change in behavior of the Elk.
The term, that best describes an organism that can contain up to five levels of organization to carry out life functions IS MULTI CELLULAR.
A multi cellular organism refers to an organism that is made up of many cells. The cells in multi cellular organisms are found in five different levels, these are: cells, tissues, organs, systems and organism. The cell level is the most basic level while the organism level is the most advanced level. Multi cellular organisms can operate in all these five levels.
