Answer:
D. is transcriptionally inactive.
Explanation:
Euchromatin is the part of chromosomes which are loose in form and are involved in the transcription process because these are available for the transcription into specific protein products. On the other hand, heterochromatin is the region of chromosomes that appears dark in staining process. This region is transcriptionally inactive because of the DNA template in the DNA-protein complexes and which means that genes present in the region are not active and not involved in the process of transcription.
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Answer:
The DNA mutation causes a change in the amino acid sequence for hemoglobin, which causes a change in the shape of red blood cells.
Explanation:
Sickle cell anemia is one of a group of disorders known as sickle cell disease. Sickle cell anemia is an inherited red blood cell disorder in which there aren't enough healthy red blood cells to carry oxygen throughout your body.
Normally, the flexible, round red blood cells move easily through blood vessels. In sickle cell anemia, the red blood are shaped like sickles or crescent moons. These rigid, sticky cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.
Sickle cell anemia is caused by a mutation in the gene that tells your body to make the iron-rich compound that makes blood red and enables red blood cells to carry oxygen from your lungs throughout your body (hemoglobin). In sickle cell anemia, the abnormal hemoglobin causes red blood cells to become rigid, sticky and misshapen.
The sickle cell mutation reflects a single change in the amino acid building blocks of the oxygen-transport protein, hemoglobin. This protein, which is the component that gives red cells their color, has two subunits. The alpha subunit is normal in people with sickle cell disease. The beta subunit has the amino acid valine at position 6 instead of the glutamic acid that is normally present. The alteration is the basis of all the problems that occur in people with sickle cell disease.
Sponges absent
Cnidarians not jointed (Aquatic organisms, all have tentacles with nematocysts - stinging cells, used to capture food.)
Roundworms absent (AKA nematodes are unsegmented, colorless and do not have appendages).
Annelids not jointed (With the exception of leeches, all annelids have chitonous hair-like structures projecting from their cuticle. These appendages fulfill different functions in different species.)
Mollusks not jointed (Invertebrates that lack hard appendages such as legs or antennae)
Arthropods jointed (the arthropods are the only invertebrates to have jointed appendages)
Echinoderms not jointed (Due to their radial symmetry, all echinoderms have appendages which point outward from the center of the body like the spokes on a wheel.)
and vertebrate jointed
Answer:the possession of feathers
Explanation:birds are warm blooded animals , that possess feathers.these feathers cover their bodies and used for flight and warmth.their forelimbs are modified into wings,which fold into a Z shape at rest.feathers grow from the skin follicles and are replaced by scales on their legs.they possess oil gland to dress the feathers.
Other features of birds include
1) beaks with no teeth
2) fully ossified bones with air cavities
3)females with left ovary and oviducts only
