Answer: C. 30 - 50 million years ago
Explanation:
Fossils found in layer Y formed 30 million years ago according to the graph above. Similarly, fossils found in layer Z formed 50 million years ago.
If a fossil (fern fossil) is found between layer Y and layer Z, it means that it formed between the years that the fossils in layers Y and Z formed which is 30 - 50 million years ago.
A protist has a nucleus inside of it to make it a Eukaryote, if it had no nucleus it would be consider a Prokaryote
Answer:
large central vacuole
cell wall
Explanation:
Let me clear some things up for you. There are two types of cells - Prokaryotes and Eukaryotes. The principle difference between these types of cells are the structure of their genome. In case of prokaryotes, the genomic matter do not have a defined structure, it just kind of floats around in the protoplasm. But in the eukaryotes, the genome is more structured, have all kinds of proteins associated with them, and is surrounded by a two layered sack called the nuclear membrane. Both plant and animal cells have these feature of structured nucleus, therefore, they are both eukaryotes.
Now for the difference between plant and animal cells. the features you mentioned are unique about plant cells, but do not rule them out from being eukaryotes, as the 'true' structure of the nucleus is still there. Cell walls are necessary for the plant cells because plants do not posses an endoskeleton like most of the animals do. The cell wall makes the whole plant rigid so they don't fall apart or appear like a blob. Chloroplast is where photosynthesis happens, so it should most definitely be in a plant cell. Animals don't do photosynthesis so they don't have chloroplasts. Vacuoles are also present in animal cells, but they are much smaller, greater in number, and are known as lysosomes. Functionally they are virtually the same.
Answer:
A: Unlike DNA, XNA replicates conservatively
Explanation:
<em>The replication of the DNA is </em><em>semi conservative.</em><em> This means that newly replicated double helix DNAs usually consist of one parental strands and one newly synthesized strands. The parental DNA unwinds and each strand serves as template for the synthesis of complementary strands.</em>
In the case of XNA, the two strands of parental XNA were found intact, meaning that the newly produced XNA consist of two newly synthesized strands. This thus means that the replication process is conservative.
Hence, unlike DNA replication that is semi conservative, XNA replication is conservative.
