Science experiments are being abandoned in schools because of fears of legal action, some of the country's top scientists have warned the Government.
And concerns about animal rights and pupil sensitivities had led to an alarming decline in dissections in biology classes, the Lords science and technology committee was told.
The committee was also told that new regulations governing disposal of waste from chemistry and biology experiments are set to make the situation even worse.
It heard pupils are getting less chance to do experiments because teachers fear litigation if anyone is hurt. The committee is engaged in an inquiry into the state of science in schools.
Fertility expert Lord Winston, the committee's chairman, said he was particularly concerned by the decline in dissection and field trips.
He had done a wide range of "extraordinarily exciting" dissections in his school days, at St Paul's, London, and "really saw working biology in a way which I think our schoolchildren now cannot do".
Giving evidence to the committee, schools minister Estelle Morris said: "We live in a society where people are increasingly worried about risk. I understand what science teachers are saying but I think they are being over-cautious.
"I would not want that practical work taken away from the curriculum. To me that is what science is all about."
She added that dissection had probably suffered because children today were from "very different cultures" and had "different sensitivities".
But she admitted that under-investment had contributed to the decline of practicals. "That is why we have set aside money for (improving) laboratories. I do not think we are half-way there - we have not yet reached the level we want this year."
Cross-bencher Lord Lewis of Newnham, a distinguished retired chemist, said the chemistry currenty done in schools was "pathetic".
He said: "The situation is being compounded by new regulations about the disposal of chemical and biological waste. In the future this will no longer be allowed to mix with other waste. This is just another brake you are putting on teachers."
Dr David Moore, chairman of the Association for Science Education, told the committee earlier that the association had been asked to support three science teachers facing legal action in the past 10 years.
He said: "Practical science is still safer than being out on the playing field or in the gymnasium, but there is an attitude that says: 'If I get this wrong, I may get sued.'" But Justin Dillon, a leading researcher into science in schools at King's College London, said practical work did not necessarily lead to higher standards.
He said international comparisons showed that countries such as Singapore performed just as well as England even though their children did much less practical work.
But employers have expressed concern about new recruits' lack of practical experience.
Professor Alan Malcolm, chief executive of the Institute of Biology, said:
"Universities are disappointed with the lack of technical skills of their undergraduates, and employers are disappointed both with school-leavers and the graduates they recruit.
"It is a serious problem caused mainly by lack of funding for school laboratories which could have damaging consequences for science in this country."
Professor Nigel Paine, director of Science Year - the 12-month-long drive to promote science that starts in September - said he hoped to revive experiments by issuing guidance on how to do them safely and developing computer packages that could simulate dissections.
He said: "Young people have told us that what really motivates them is doing things, not just being told about them. This is an area we must address if we are to put the excitement back into science."