Question

why is trna called transfer rna?
o a they look like a little truck under the microscope
o b it carries/transfers codes for proteins from the cytoplasm to the dna
o c it carries/transfers the code for one gene from the dna to the ribosome
o d it carries/transfers a specific amino acid to the ribosome during protein synthesis
question 21
a timeline of important discoveries about dna is shown below. these discoveries have contributed to our current knowledge about dna
which statement best summarizes the development of knowledge about dna over time?
o a ideas about dna have remained unchanged over time
o b changes in ideas about dna are based on opinion
o c past knowledge about dna was discarded as each new discovery was made
o d scientists gained more knowledge about dna as new evidence became available

Explanation:

For the first question:

• Option a is incorrect as the name is not based on its appearance under a microscope.
• Option b is wrong because tRNA does not transfer codes from cytoplasm to DNA.
• Option c is incorrect as mRNA (not tRNA) transfers the code for a gene from DNA to ribosome.
• Option d is correct as tRNA's main function is to transfer a specific amino acid to the ribosome during protein synthesis.

For the second question:

• Option a is wrong as knowledge about DNA has changed over time.
• Option b is incorrect as changes in ideas about DNA are based on evidence, not opinion.
• Option c is wrong as past knowledge is built upon, not discarded.
• Option d is correct as scientists gain more knowledge about DNA as new evidence becomes available.

Answer:

First question: d. It carries/transfers a specific amino acid to the ribosome during protein synthesis.
Second question: d. Scientists gained more knowledge about DNA as new evidence became available.