The mother of a Florida woman accused of killing her 2-year-old daughter testified Thursday that she had conducted Internet searches about chloroform on a family computer, directly contradicting prosecutors' theory that it was the suspect who made the queries.

Casey Anthony's mother, Cindy, said she had run the chloroform queries while looking up information on chlorophyll, a green pigment found in plants. She believed her dogs may have been eating bamboo leaves containing chlorophyll. Cindy Anthony also said she ran searches on other chemicals, such as hydrogen peroxide, after she was informed about a hand sanitizer scare.

Casey Anthony listened to her mother's testimony without showing emotion.

The testimony was a surprise to prosecutors who contend that Casey Anthony made the searches. During cross-examination, prosecutor Linda Drane Burdick suggested that Cindy Anthony never mentioned the searches during depositions and that work records show that Cindy Anthony was at her job during the time the searches were made on the family's home computer.

Cindy Anthony responded that she could leave work when she needed to and that the work records might not have reflected her absence.

"You were aware that computer searches were an issue?" Drane Burdick said.

Drane Burdick asked Cindy Anthony whether she remembered denying that she conducted the searches during her 2009 deposition.

"I did not look up how to make chloroform. I looked up chloroform," Cindy Anthony said. "I did tell the detectives, and I did tell the state attorneys about the searches."

Cindy Anthony told Drane Burdick she did not run searches on household weapons, chloroform habit or neck-breaking, although she said she remembered a YouTube video involving a skateboarder. The skateboarder's trick was described as a "neck-breaking feat," she said.

Chloroform is a chemical compound that can be used to knock someone unconscious and also is found in human decomposition.

The body of Casey Anthony's daughter, Caylee, was found in December 2008, almost six months after she disappeared in Orlando. Prosecutors believe she suffocated her daughter in June 2008. She didn't report her missing for 31 days.

Earlier in the trial, a medical examiner testified that even a small amount of chloroform would be sufficient to cause the death of a child.

Cindy Anthony also said stains in the trunk of Casey Anthony's car were present when the family bought the car in 2000. Prosecutors contend the child's body was in the car trunk and then dumped in a wooded area near the Anthony home. Prosecutors have presented extensive evidence of human decomposition in the car trunk, including stains.

Sgt. Kevin Stenger of the Orange County Sheriff's Office also testified Thursday about deputies' investigation of the Anthony family computer. Prosecutors contend someone in the Anthony home ran searches on chloroform as many as 84 times. But defense attorney Jose Baez asked Stenger about discrepancies in the data showing how many times someone searched about chloroform.

During cross-examination, Drane-Burdick presented evidence that someone in the Anthony home conducted a search on how to make chloroform.

Casey Anthony has pleaded not guilty to first-degree murder and could face the death penalty if convicted of that charge.