In order to allow gene expression, histone modifying enzymes interact with core histones to modulate their affinity for the DNA and/or other histones, so that specific sequences can be exposed to allow for transcription. From the list below, choose all of the statements that are true.

A) the 'tails' of core histones are an important site for covalent modifications by histone modifying enzymes
B) Histones can be modified in a variety of ways, including methylation, acetylation and phosphorylation.
C) Histones modifications are binary, meaning that modifcations will turn the histone 'on' or 'off'.
D) Histone modifying enzymes can slide the core histones along the DNA without removing it.
E) The H1 histone is sometimes removed, to help expose the DNA for transcription

A, B, C and D are correct

Explanation:

The statement E is not correct because the Histone H1 does not form the histone octamer that is associated with DNA to form the nucleosomes. The histones in the nucleosome are H2A, H2B, H3 and H4.

The function of H1 is to act as a linker between nucleosomes in the chromatin fiber.

there are 35 white marbles

step-by-step explanation:

y- yellow marbles

4y + 5 = 45

subtract 5 from both sides

4y = 40

divide for from both sides

y = 10

plug in 10 to get 40 yellow marbles then subtract by 5 to get 35 marbles

thus there are only 10 yellow marbles

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.