Question

Part A: Why do some scientists believe that RNA, rather than DNA, was the first genetic material?

RNA can replicate more accurately than DNA.

RNA has both information storage and catalytic properties.

RNA could have evolved into DNA.

All the proto-cells on early Earth contained RNA.

RNA contains uracil in place of thymine

Part B: What is most likely if genes from different species are determined to be homologous?

The species being compared will also have a similar genome size and structure.

Homology is found in gene structure but the function of the gene products will be different.

The genes descended from a common ancestor.

Homology is observed because of convergent evolution.

The homology is a result of chance mutations.

Part C: Which of the following can be duplicated in a genome?

DNA sequences below a minimum size only

entire chromosomes only

DNA sequences above a minimum size only

sequences, chromosomes, or sets of chromosomes

entire sets of chromosomes only

Part D: The hypothesis for the origin of eukaryotes through serial endosymbiosis proposes that

mitochondria and plastids replicate in a manner similar to eukaryotes.

the ancestors of mitochondria were aerobic heterotrophic prokaryotes, while the ancestors of plastids were photosynthetic prokaryotes.

genes in mitochondria and plastids are similar to genes of ancient eukaryotes.

eukaryotes likely evolved from the fusion of small prokaryotic and small eukaryotic cells.

Answer 1

1 RNA has both information storage and catalytic properties - it is the first genetic material from which DNA is evolved. Because it stores the information which is to be coded, it also acts as enzymes possessing catalytic properties.

2 The genes descended from a common ancestor, - homology is defined as common similarities between different species which is descended from a common ancestor.

3 entire sets of chromosomes only - during replication entire genome is replicated but not specific genes. Therfore entire chromosome duplicates.

4 eukaryotes likely evolved from the fusion of small prokaryotic and small eukaryotic cells - endosymbiosis close symbiotic relationship i. e. One cell resides in other by engulfing by which mitochondria- prokaryote present in eukaryotes obtained by fusion.