The following are some common procedures that we should take action of when using a bunsen burner to ensure our safety:
1. Wear safety goggles. Tie up long hair and school ties if needed. This can lower the risk of catching on fire. Put a heatproof mat underneath the Bunsen burner, put a tripod and the beaker of water for heating on top of the burner.
2. Close the air hole. Before we start up the burner, the air hole must be closed or green flame (striking back) may occur
3. light up a match or a lighter. Put it over the chimney.
4. Turn on the gas tap, you should be able to see a yellow flame now. Remove the lighter or match and open the air hole. We should have a blue flame by now.
5. the water should start to heat up. Never touch the hot beaker with bare hands.
6. When the water is heated up to the temperature they wanted to, it's time to close the air hole and turn off the gas tap.
7. If they need to move the hot beaker, use heat protection gloves
These should be the correct procedures that they should follow in order to heat the water safely.
Hope it helps!
A microscope is to see smaller things that you can’t see and it is a really good tool.
Answer:
C. They have a continental rise.
Explanation:
Answer:
C
Explanation:
I think its C . A transcriptional repressor usually represses the transcription pathway when its active. According to the question, the repressor is not usually active until an effector molecule binds to it making it active and blocking the transcription pathway. So if the region where the effector binds on the repressor is mutated i.e. it turns nonfunctional that means the effector cannot bind to repressor which means repressor cannot become active to block transcription which in turn increases the transcription of gene A because repressor cannot repress it since it is inactive due to its inability to bind to the effector.
ALOT of words please lmk if it makes sense
Answer no 8:
The correct option is D) Antelopes with muscular legs are bale to outrun their predators better than antelopes with poor muscle tone. Thus they lived to reproduce.
Explanation:
Genetic variations in a population are the main reason that natural selection tends to occur. Natural selection favours those organisms which have better characteristics.The organisms with better traits are able to reproduce and pass on their characteristics to their offsprings.
Answer No 10:
The correct option is A) Phenotype directly influences the interaction of an organism with its environment.
Explanation:
The interactions between the phenotypic traits and the environment analyze whether a particular organism will be able to survive and pass on its characteristics to its offspring. Hence, the phenotype directly influences the interaction of an organism with its environment.
Answer No 9
The correct option is A) resistance to a virus
Explanation:
Mutations can be described as any changes which occur in the DNA of an organism. Mutations might be beneficial or harmful depending on the location where the mutation arises. Viruses are usually harmful for eukaryotes. Hence, the correct option is A.
Answer No 11:
The correct option is C) Giraffes with longer necks survived because they were better suited to the environment.
Explanation:
Natural selection tends to favour those organsims which are better suited to live in an environment. Those organisms with better characteristics are able to survive and pass on their traits to their offsprings.
The giraffes with longer necks were better adapted to live in the environment and hence were favoured by natural selection.
Answer No 12:
The correct option is D) selective breeding
Explanation:
Selective breeding can be described as a technique in which organisms with better characteristics are crossed, so that offsprings with better characteristics can be produced. Selective breeding is done by humans where as natural selection is done by the nature.
