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.
Otrophic level
food chain
food pyramid
energy path
Answer:
i believe it is energy path
Explanation:
B. nucleolus.
C. chromatin.
D. DNA.
Answer:
Option A, Cytoplasm
Explanation:
Cytoplasm is the fluid contained with in the cell membrane into which all cell organelles are found including the nucleus. Cytoplasm basically has two parts a) endoplasm and b) ectoplasm. The endoplasm has all the organelles while the ectoplasm is the fluid at the periphery of cell membrane. The cell memebrane keep the cytoplasm confined with in the cell and does not allow it to spill.
Since all the cell components are found with in the cytoplasm, it is clear that cytoplasm lies out of the nucleus. Thus, option A is correct.
Answer:
The correct answer will be option- A
Explanation:
The nucleus is the membrane organelle which encloses the DNA of the organisms. The presence of the nucleus is the characteristic feature of the eukaryotes.
The nucleus encloses the genetic material in the form of either DNA or a loosely arranged structure called chromatin. The nucleus also contains a structure called nucleolus distinguished by a dense round structure during the interphase.
Since the nucleus lacks the cytoplasm which is enclosed by the cell membrane of the cell therefore, option-A is the correct answer.
- ground
- dermal
Answer:
vascular the answer above is incorrect.
Explanation:
The doctor should reassure the patient that exposure to radiation from a medical device becomes dangerous only if it is exposed for a long time, in high doses, or repeatedly.
It is true that there is a particular risk for pregnant women with regard to the fetus. In this case, the ratio between the benefit to the patient and the possible risk of side effects should always be taken into account.