Answer:
The correct answer will be option-B
Explanation:
The data collected on the bacterial species in the Yellowstone national park involved:
1. habitat characteristics
2.DNA of bacteria from each population
3. compared with other species of the park
Based on these features, the biologist could apply all the types of species concept like ecological species concept which allows the study of the species from the same niche.
Also, they compared the DNA of the species of the bacteria and compared them which allows to trace the evolutionary patterns and showing the phylogenetic relationship.
Since bacteria do not reproduce by the sexual reproduction, therefore, a biologist cannot apply the biological species concept which states that species can be called species which can reproduce only with the closely rated species only or the individual of the same species.
Thus, Option-B is the correct answer.
Answer:
The correct answer is option (d)-"All of these are found in the fossil record and have been used by scientists to understand human evolution".
Explanation:
There is plenty of evidence that supports the proposal of how humans has evolved during past times. The fossil records that scientists has used understand human evolutionary patterns include the following. Ardipithecus ramidus bones that revealed advances in upright walking, even tough they had a small brain that measured between 300 and 350 cm3. Australopithecus lack of an opposable big toe suggest that they lived on the ground instead of in trees. Homo erectus was the first species to use and control fire, as suggested by evidence of microscopic traces of wood ash.
Answer:
extinct
dormant (Haven't erupted in 4/6yrs
The question is incomplete as it does not have the options which are:
A. Gram-negative bacilli cannot cause harm to the cell; only Gram-positive bacilli can harm the cell.
B. Gram-negative bacilli release endotoxins that cause cell injury and increased capillary permeability.
C. Gram-negative bacilli excrete elaborate exotoxins that interfere with cellular production of ATP.
D. Gram-negative bacilli enter the cell and disrupt its ability to replicate.
Answer:
B. Gram-negative bacilli release endotoxins that cause cell injury and increased capillary permeability.
Explanation:
Gram-negative bacteria are pathogenic in nature due to the composition of their cell wall. Their cell wall contains an additional layer of a molecule called lipopolysaccharides or LPS.
The LPS layer is toxic in nature and is known as endotoxin and is involved in the pathogenicity of the bacteria as the toxin causes the injury to the Endothelial cell membrane of the host cell.
When the bacteria cell is lysed and the LPS circulates in the blood, then LPS binds the receptors and acts on CD14. This attracts the neutrophils at the site and can cause vascular injury due to increased capillary permeability.
Thus, Option-B is the correct answer.
Answer:
Cost : The expenditure incurred by a producer on the factor as well as non-factor inputs for a given amount of output of a commodity.
