Hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl groups.
These groups play an important role in the formation of molecules like DNA, proteins, carbohydrates, and lipids.
Carboxyl abs Carbonyl help with Carbohydrates.
Answer:
The correct answer would be "Myosin heads attach to sites on actin filaments".
The muscle cell or myofibril consists of two types of protein filaments namely; actin (thin filament) and myosin (thick filament).
The myosin heads attach to the binding sites on the actin filaments and pull it towards the M-line in order to produce contraction.
The hydrolysis of ATP provides energy for this contraction cycle.
Insertion or

of genes to produce desired proteins.
Answer:
1. d. changes in the methylation patterns of <em>loci</em> involved in growth and metabolic disease
2. b. differences in the expression of metabolic genes
d. changes in histone acetylation patterns
Explanation:
Epigenetics refers to the study of heritable changes in gene expression which are not dependent on DNA sequence. Epigenetic mechanisms involve DNA methylation, histone modifications (acetylation, methylation, phosphorylation, etc) and regulatory non-coding RNA (ncRNA) pathways. These epigenetic mechanisms work together and mutually reinforce each other in order to modulate gene expression (either by activating or suppressing gene expression). In consequence, transcriptome data (e.g., genes differentially expressed in particular tissues/cells or stages of development) is an important piece of evidence indicating the existence of epigenetic modulation.