Ans.
Chromatin molecules are made up of DNA and histone proteins. Modification of chromatin structure include covalent, post-translational changes in histone proteins, present in chromation. Acetylation and methylation are two important histone modifications that affect structure of chromatin molecules.
Acetylation involves addition of an acetyl group to histones that increases transcription of DNA by loosen the association between DNA and nucleosome.
Methylation involves addition of a methyl group to histones that results in condensation of chromatin molecule and thus, decreases transcription of DNA.
Both acetylation and methylation are reversible processes.
Many chromatin modifications are genetic, means they can pass from one generation to another generation, called epigenetic modifications.
Thus, options B), C), D), E), and F).
B definitely because d is just dumb, c is not possible, a is not even true so b
Answer:
The correct answer is- Organ, organelles
Explanation:
Cells comes together and make tissue and different tissue organized to form an organ. So organs are made up of a group of two or more tissue type which perform specific function in an organism. For example, the heart pumps the blood, kidney which filters the blood.
Organelle are microscopic structures in the cell for example nucleus, Golgi, endoplasmic reticulum. Each organelle performs a specific function like organs. Eukaryotes have membrane-bound organelles and prokaryotes lack membrane-bound organelles. Therefore the correct answer is organs and organelle.
The correct answer is C. It is so strict because a foreign species could compete with a native species and drive it to extinction.
The Hawaiian islands are one of the geographical isolated islands which faces the problem of the invasive species affecting the biodiversity of the island negatively.
The foreign species is equipped better to survive in the Hawaiian habitat and competes with the native species for the resources and food. The interaction and competition of the foreign species in the Hawaiian environment and habitat limits the resources for native species which increases the chance of the native species getting endangered.
The Hawaii Invasive Species Council along with other bodies such as department of agriculture, department of business and economic development, private and other government and non-government bodies have taken initiatives towards eradication of invasive species by strict laws.
