Question

what is the :

Control Group-

Test Group-

Dependent Variable(s)-

Independent Variable(s)-

Controlled Variables(s)-

Cooked Garlic Still kills bacteria Science News: 6/10/2006, Vol. 169 Issue 23, p366-366, 1/4p Researchers have long known that chemicals isolated from raw garlic can kill a wide variety of bacteria, but the cooked herb hadn't been tested. A new study suggests that cooked garlic can still kill bacteria, though less efficiently than does a raw bulb. Microbiologist Chitra Wendakoon of New Mexico State University in Las Cruces worked with several common types of foodborne bacteria, such as strains of Salmonella, Listeria, and Shigella. She created extracts of raw garlic and cooked garlic. Wendakoon then added the raw and cooked garlic extracts to lab dishes in which the bacteria were growing. Within a day, bacteria-free zones surrounded the spots where either the raw or cooked-garlic extracts had been placed. However, the bacteria- free zone for the raw extract was about twice as large as that for the cooked ohe. Wendakoon obtained similar results when she tested the extracts on bacteria growing in a nutrient broth. In that experiment, cooked garlic killed hundreds of thousands of bacteria, but raw garlic killed about 10 times as many. The finding suggests that some of garlic's antibacterial components "are probably heat stable," says Wendakoon. The next step, she adds, will be to isolate these hardy antibacterial compounds.

Answer 1

control group

bacteria to which the raw garlic extract is added are taken as control group.

(control group does not receive the experimental sample and it is taken as standard to measure the activity of test group)

test group

food born bacteria to which the cooked garlic extract is added are taken as test group.

(a test group is a population which receives the experimental sample.)

dependent variable

cooked garlic paste

( dependent variable is a variable that is tested in the experiment)

independent variable

type of food borne bacteria

(it is a variable that is changed to test the dependent variable)

controlled variable

raw and cooked garlic paste

(it is the variables that is unchanged throughout the research)