3. viruses containing rna as their genetic information are called (1 point)
retroviruses.
prophages.
bacteriophages.
capsids.
4. in the six-kingdom classification system, bacteria are divided into two kingdoms, eubacteria and archaebacteria. the main difference in the cell structures of the two groups of bacteria is that (1 point)
eubacteria do not have peptidoglycan in their cell walls, but archaebacteria do.
archaebacteria do not have peptidoglycan in their cell walls, but eubacteria do.
eubacteria have chlorophyll in their cells, but archaebacteria do not.
archaebacteria have chlorophyll in their cells, but eubacteria do not.
5. how do bacteria contribute to an ecosystem? (1 point)
some bacteria reduce the number of parasites infesting organisms in an ecosystem.
some bacteria provide nutrients and raw materials for organisms in an ecosystem.
some bacteria are a primary food source for most of the consumers in an ecosystem.
some bacteria provide protection from viral infections for the organisms in an ecosystem.
6. which of the following roles of bacteria is not a benefit to human bodies? (1 point)
digesting food
preventing diabetes
making vitamins
acting as a pathogen
7. two ways bacteria cause disease is by using the cells of the organism they infect as food and by (1 point)
making antibiotics.
releasing toxins.
releasing viruses.
releasing disinfectants.

Since plants are not able to directly use atmospheric nitrogen, it must be converted into different form through a nitrogen cycle. Thanks to nitrogen fixing bacteria which converts atmospheric nitrogen into ammonium, nitrogen in the form of ammonium is now available to plants. Also, bacteria are decomposers. After the death of producers and consumers, decomposers eat dead organisms and release carbon, nitrogen, and other elements into the environment.

Q6. The answer is acting as a pathogen.

A pathogen is a microorganism that can cause a disease. Among different groups of organisms, some bacteria can be pathogens. Some species are pathogenic and are able to cause diseases such as tuberculosis, tetanus, cholera, etc. This pathogenic role of bacteria cannot be beneficial for humans. On the other hand, usage of bacteria in genetic engineering for production of some vitamins or hormones, such as insulin that lack in diabetic patients, can be of a great benefit to humans.

Q7. The answer is releasing toxins.

Bacteria can produce toxins that can promote an infection and cause a disease. Bacterial toxins can be endotoxins and exotoxins. EXOtoxins are after secretion released out of the cell. ENDOtoxins remain as the part of the bacteria and they are released only if bacteria are killed by the immune system of the organism. The organism will response to the presence of endotoxins and usually, inflammation occurs.

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.