Answer:
These homologous structure indicates a common ancestry
Explanation:
When 4 organisms show homologous structures, they indicates they belongs to a common ancestor from where the changes takes place in them.
The organs which are structurally dissimilar but functionally same are called as homologous organism.
Answer:
It is essentially a broth culture filtrate of the penicillium mould.
Explanation:
- Alexander Fleming invented penicillin an antibiotic in 1928. These have been rated as the most important scientific discovery, being among the first antibiotics to be effective against bacterial infection.
- Penicillin belongs to different families that are selective against a large variety of bacteria.
- In fact, this antibiotic was discovered by fleming and accident in which he left a platter containing staphylococci open and was contaminated by green mould. There was an area of inhibited bacterial growth around the mould from which he inferred that the mould produced a material that inhibited bacterial growth. This was found to be a penicillium mould through further study.
- I assume penicillin is the most significant discovery so far because it was the first antibiotic ever discovered against bacterial infection in the absence of any drug.
Some of them could have to emigrate or move lower down the tree and adapt to their new habitat<span />