The Structure of Prokaryote and Eukaryote Cells
During the 1950s, scientists developed the concept that all organisms may be classified as prokaryotes or eukaryotes. The cells of all prokaryotes and eukaryotes possess two basic features: a plasma membrane, also called a cell membrane, and cytoplasm. However, the cells of prokaryotes are simpler than those of eukaryotes. For example, prokaryotic cells lack a nucleus, while eukaryotic cells have a nucleus. Prokaryotic cells lack internal cellular bodies (organelles), while eukaryotic cells possess them. Examples of prokaryotes are bacteria and archaea. Examples of eukaryotes are protists, fungi, plants, and animals (everything except prokaryotes).
Answer options:
- extraction and observation of DNA
- identification of ribose and deoxyribose
- recognition of RNA as DNA’s messenger
- construction of an accurate DNA model
Answer:
- identification of ribose and deoxyribose
Explanation:
Phoebus Levene was an American biochemist who studied the structure of DNA and RNA. He was able to isolate the sugars (ribose and deoxyribose) from the nucleic acids, which are an important part of their structure.
He also determined how the nucleic acid components combine to form the nucleotides, the basic building blocks of nucleic acids, and how the nucleotides combine in chains to form the polymer.
Factors that determine the rate of stream erosion-
➡️ Rainfall (more rain more erosion). ✔️
➡️water velocity ✔️
➡️shape, size and depth of channel ✔️
➡️stream capacity to transport eroded material, and the nature of the material being transported✔️
➡️Gradient (Steepness or slope) ✔️
➡️Discharge (Amount of water carried at a given time) ✔️
➡️Load (The materials carried by a stream)
Rainfall (more rain more erosion). ✔️
➡️Slope (the steeper the slope the faster the water will flow) ✔️
➡️Geology (if the bedrock is a soft silt it will erode faster than granite).✔️
Answer:
Frameshift mutations change the entire protein sequence and messes up the entire amino acid sequence that occurs after mutations, but substitution only changes one single amino acid.
Answer:
answer is the ability to do work
