Tutor profile: Jennifer O.
Subject: Veterinarian Science
What is FIV and can a cat with this issue safely live in a house with other cats?
FIV is feline immunodeficiency virus, which is similar in effect to human HIV. Cats with FIV may or may not become ill during their lifetime. If a cat develops symptoms as a result of its FIV positive status, these symptoms generally appear around or after the age of 8 years of age. FIV disrupts and weakens the immune system, allowing secondary infections from normally harmless bacteria, viruses and other microbiota to become life-threatening. Cats that are FIV positive are more likely to have serious dental disease, for example. The disease is transmitted through deep bite wounds, and is therefore not usually contracted until after 6 months of age, when unneutered cats begin to fight for territory and mates. It was previously thought that mothers transmitted FIV to kittens automatically, but recent research has indicated that this is not the usual case, and many veterinarians no longer test for FIV until after 6 months of age to avoid false positives due to maternal antibodies. A vaccine is available, but the downside to this vaccine is that cats who receive this vaccine will test positive on the most commonly used in-house tests, despite being disease free. It is generally accepted, and a paper was recently published to this effect, that cats that are FIV positive can safely live with FIV negative cats as long as they are spayed and neutered and do not fight aggressively within the household.
Describe the process of protein synthesis and explain how it is important to living things.
There are two stages to protein synthesis (the process cells use to make protein for energy). Stage 1: Transcription: This is the process that the nucleus of the cell uses to re-write or copy (transcribe) DNA into a messenger strip of RNA (mRNA) that will be sent to the ribosomes to be decoded (translated) into a protein. Stage 1 of transcription is the initiation stage where DNA is unwound so that an enzyme (RNA polymerase) can read the bases attached to the DNA strand. The mRNA is then elongated as chemicals called nucleotides are added to the strip. Termination is the final stage of mRNA formation, which is the completion of the mRNA strand and its detachment from the DNA strand. At this point, in eukaryotes, several more steps are taken to slice, edit and "polish off" the mRNA through polyadenation, which helps protect the mRNA and export it from the nucleus. Stage 2: Translation: Once the mRNA reaches the ribosome, the sequence of chemical instructions is read, and tRNA brings amino acids to the ribosome to attach to the mRNA in the correct sequence to form the protein. Bonds are formed between the amino acids and the result is called a "polypeptide chain". This chain may be the finished protein, or it may require some additional processing to form the finished result.
Describe petechiae, the mechanism of their formation and list several possible causes.
Petechiae (or petechial hemorrhages) are generally caused by ruptures in the capillaries, or small blood vessels that serve as the smallest arteries and veins in the circulatory system. These ruptures cause blood to leak out of the vessels into the skin, which results in the formation of pinpoint bruises - the classic signs of petechiae. These ruptures are often caused by disruption of vascular integrity or platelet dysfunction Causes of petechial hemorrhages include straining during difficult activities, such as giving birth, excessive coughing, or straining when lifting weights or experiencing constipation. Petechiae may be a symptom of some infectious diseases such as strep throat/scarlet fever, viral hemorrhagic fevers (such as Ebola, Lassa Virus or Marburg virus), Rocky Mountain Spotted Fever or Epstein-Barr. Conditions such as thrombocytopenia (a lack of platelets in the blood which decreases clotting ability), vasculitis (inflammation of the blood vessels which can make the walls of the vessels weaker and therefore, leaky), or vitamin deficiencies (such as Vitamin C or Vitamin K) may also lead to petechial hemorrhages. In addition, there are numerous prescription drugs that may cause these lesions; among them are blood thinners and other cardiac drugs, and NSAIDs (non-steroidal anti-inflammatory drugs).
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