Examples of histone modifications are acetylation (by histone acetyltransferase, or HAT), which is often linked to gene activation, and deacetylation (by histone deacetylases, or HDACs), which often leads to gene silencing typical of heterochromatin. Such heterochromatinizat ion is initiated from a nucleation site and spreads bidirectionally until encountering boundaries that delimit the silenced areas.

In the heterozygous state (w +/w), a variegated eye is produced, with white and red patches.

How might one explain position-effect variegation in terms of histone acetylation and/or deacetylation? Select all that apply.

1. The white patches are caused by the acetylation of the histones associated with the DNA of the w + allele.

2. The white patches are caused by the deacetylation of the histones associated with the DNA of the w + allele.

3. The red patches are caused by the acetylation of the histones associated with the DNA of the w + allele.

4. The red patches are caused by the deacetylation of the histones associated with the DNA of the w + allele.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.

the answer is d.) homologous; have mammary glands

events in order:

1.       vishnu schist

2. zoroaster granite

3. bass limestone

4. hakatar   shale

5. igneous intrusion

6. shinumo quartzite

7. dox sandstone

8. tapeats limestone

9. bright angel shale

10. muav limestone

11. temple butte limestone

12. redwall limestone  

nonconformity

answer: the unkar group shows angular unconformity because the layers are turned at angle.

unconformity

answer: specifically the angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled. an angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled.

disconformity

answer: the disconformities aremarked irregular lines between the sedimentaryrocks layers.

a symbiotic relationship with the mitochondria