Photo AI
Complete Table 2 to show three differences between DNA in the nucleus of a plant cell and DNA in a prokaryotic cell - AQA - A-Level Biology - Question 8 - 2020 - Paper 1
Question 8
Complete Table 2 to show three differences between DNA in the nucleus of a plant cell and DNA in a prokaryotic cell. Table 2 DNA in the nucleus of a plant cell ... show full transcript
Worked Solution & Example Answer:Complete Table 2 to show three differences between DNA in the nucleus of a plant cell and DNA in a prokaryotic cell - AQA - A-Level Biology - Question 8 - 2020 - Paper 1
Step 1
DNA in the nucleus of a plant cell vs DNA in a prokaryotic cell
Answer
-
DNA in plant cells is linear, whereas DNA in prokaryotic cells is mostly circular.
-
Plant cell DNA is associated with histones and organized into chromosomes, unlike prokaryotic DNA which typically lacks histones.
-
Plant cells contain plasmids, while prokaryotic DNA generally exists as a single strand, lacking typical eukaryotic chromosomal structure.
Step 2
Define ‘non-coding base sequences’ and describe their position
Answer
Non-coding base sequences are segments of DNA that do not code for proteins or polypeptides, meaning they are not transcribed into RNA, nor do they translate into amino acids. These sequences are usually positioned between genes or may serve regulatory functions.
Step 3
Step 4
How the percentage similarity affects the validity of the phylogenetic tree
Answer
The finding that species T shows a percentage similarity of 66% indicates a high degree of similarity with the studied species. This suggests that species T is likely more closely related to these species than originally posited in the phylogenetic tree, implying potential discrepancies in the tree’s accuracy regarding species relationships.