Answer:10%
Explanation:
I just took the test
The last universal common ancestor (LUCA) is the most recent organism from which all organisms on Earth descended. While it is challenging to definitively determine the specific characteristics of LUCA, scientists have proposed certain properties that it likely possessed based on evolutionary and genetic evidence. Let's analyze each property mentioned in the question:
1. Simple cellular structure:
- LUCA is believed to have had a simple cellular structure. This means it likely had basic cellular components, such as a cell membrane, cytoplasm, and possibly some form of genetic material.
2. Anaerobic metabolism:
- LUCA is thought to have relied on anaerobic metabolism, which means it obtained energy from sources other than oxygen. This is because molecular oxygen was not abundant in the early Earth's atmosphere when LUCA is believed to have existed.
3. Prokaryotic cell type:
- It is widely accepted that LUCA was a prokaryote, meaning it had cells lacking a nucleus or other membrane-bound organelles. Prokaryotes are considered the most ancient type of cells on Earth.
4. Extremophile characteristics:
- While it is difficult to determine the specific environmental conditions in which LUCA lived, some scientists propose that it could have been an extremophile, capable of surviving in extreme environments like high temperatures, high salinity, or acidic conditions. However, this is still a topic of scientific debate and further research is needed.
5. Heterotrophic nutritional strategy:
- LUCA is believed to have been heterotrophic, meaning it obtained nutrients by consuming organic compounds produced by other organisms. This is in contrast to autotrophs, which can produce their own food through processes like photosynthesis.
In conclusion, based on current scientific understanding, LUCA is likely to have possessed the properties of a simple cellular structure, anaerobic metabolism, prokaryotic cell type, and a heterotrophic nutritional strategy. The presence of extremophile characteristics is still a subject of ongoing research and scientific investigation.
I hope this explanation clarifies the properties that LUCA is believed to have had. Let me know if you have any further questions.
They both are commonly found on human skin.
They both make chitin in order to reinforce their cell membranes.
They both keep their DNA in the form of a nucleoid.
B. It prevents reproduction between populations.
C. It reduces competition between the populations.
D. It protects one of the populations from predation.
Answer;
B. It prevents reproduction between populations.
Explanation;
Geographical isolation refers to a population of animals, plants, or other organisms that are separated from exchanging genetic material with other organisms of the same species.
Geographic isolation causes individuals of an original species to accumulate sufficient genetic differences to prevent them breeding with each other when they are reunited.
Glycogen is a homopolysaccharide formed by units of glucose and is sometimes referred to as animal starch. It can reach up to a molecular weight of 10 to the power 8 DA which corresponds to about 600,000 glucose molecules.
The function of glycogen is that it is the principal form in which glucose is stored in animals and is present in the liver, muscle (skeletal and heart muscle) and in lower amounts in nearly all the other tissues and organs.
Glycogen makes up about 10% of liver weight and 1% of muscle weight. Although it is present in higher a concentration in the liver, the total amount stored in muscles is much higher due the greater mass of the muscles as compared to the liver.
the answer to the question is polymerization