Answer:
The correct answer is - Histones are positively charged.
Explanation:
Histone is an octamer that is made up of four proteins and each protein has 2 copies. These proteins are H2A, H2B, H3, and H4. Histone proteins are mainly made up of positively charged amino acids like arginine and lysine which gives histone proteins an overall positive charge.
This positive charge of histone plays important role in the binding of DNA around it because phosphate group present in the DNA makes DNA negatively charged molecules that are attracted by positively charged histone protein by electrostatic interaction.
This interaction results in the wrapping of DNA around the histone proteins and then compaction of DNA into chromatin. Therefore the right answer is- histones are positively charged.
Answer:
D. the law of crosscutting relationships
Explanation:
The law of cross-cutting relationships can help explain the age of the rock as it relates to the surrounding rock.
This law is one of the premise of relative dating. The relationship between the intrusion and rock body or country rock is used to discern their age.
- When intrusions cross-cuts the host rocks, they are usually younger.
- The host rock must haven emplaced before the intrusion sets in
- The intrusion utilizes weak planes within the rock body to cool and solidify.
- Now, when they are emplaced, then a vein or other intrusive bodies forms.
Quadrat method is used for estimating the number of individuals in an area. In this method, a large square area on the ground or water surface is marked, call it an enclave. The number of animals present in this enclave is counted. Then by assuming that the animals are less migratory and are uniformly distributed, their number for a large area is estimated by the use of unitary method of calculation. Example a 4 square feet area has 2 snails, then a 1000 square feet area will have (1000 x 2)/4, i.e, 500 snails in it. Fishes can be counted using this method only if they are confined in a small water body like a lake or a pond. Rivers are flowing so the fishes may move along its length which can give us an underestimate or an overestimate of their numbers. Sea has its depth and huge area, and fishes can be moving randomly in it. Hence this method will not work for river and sea fishes.
It may change the chromosomes.