During dna replication, a thymine base is removed from the dna. what type of mutation is this?

There are no options to this question but the answer is FRAMESHIFT MUTATION.

Explanation:

Changes occurs to the nuceleotide sequences in the genome of organisms from time to time. These changes are either caused by mistakes during DNA replication or induced by mutagens (mutation-causing substances). The change described here is regarded as MUTATION.

However, MUTATION can be of different types depending on how it occurs. In this question, it is called a FRAMESHIFT MUTATION. Frameshift mutation is a mutation caused by the deletion or addition of one or more nuceleotide base in the sequence, leading to an alteration in the way the sequence will be read i.e. the frameshift.

In this question, a Thymine base was removed from the sequence during DNA replication. This is a deletion mutation that will lead to changing the way the sequence will be read during translation because it has affected the three codons per amino acid reading. Hence, because it will affect the reading pattern of the sequence, it is called a FRAMESHIFT MUTATION.

Seaweed belongs to Earth's biosphere.

Explanation:

The biosphere is where the regions of the surface, atmosphere, and hydrosphere of the earth (or analogous parts of other planets) occupied by living organisms.