Question

1. Complete this table. Microbes Archaea Bacteria Protists Viruses Considered to be alive? Cellular or acellular? If cellular: prokaryotic or eukaryotic? If cellular: unicellular, multicellular, or either? General description of structure Does this category include producers? Does this category include consumers? 2. List the three ways that HIV is spread. 3. HIV makes people sick primarily by destroying one specific body system. Name that system. 4. HIV is a retrovirus. Retroviruses get their name by causing the cells they infect to do a specific cellular process backwards. What cellular process do retrovirally-infected cells do backwards?

Answer 1

Archae --

• Considered to be Alive
• Posses cell therefore ,Cellular
• Prokaryotic as they lack membrane bound nucleus. DNA is suspended freely in cytoplasm
• Single celled - have only one cell
• Structure -- posses cell wall but lacks a cell membrane. They do not have any other organelle within cytoplasm.They have flagella for their movement. Cell wall lacks peptidoglycans.

Bacteria --

• Considered alive
• Cellular
• Prokaryotic as they also lack membrane bound nucleus
• Unicellular
• They possess cell wall and cell membranes which are made up of peptidoglycans. Chromosome lie freely in cytoplasm or grouped together to form a Nucleiod. Possess fimbrae and pilli which helps in attachment to surfaces. Some bacteria possess capsuleike protective covering. Flagella for motility. Possess ribosomes and no other organelle are present.
• They possess producers like cyanobacteria
• Some bacteria are consconsumers

Protist --

• Considered alive
• Cellular
• Eukaryote ie, they possess membrane bound nucleus.
• Unicellular
• Structure -- they consists of a cell membrane like animals and cell wall like plants. They either have one single nucleus or many small nuclei. They have cilia, flagella movement and forms false arms for movement or engulfing any food or other particle. This arm is known as pseudo podia. They also posses outer protective covering known as Pellicle.
• They posses consumers ie, feed on other small organism by capturing and engulfing their prey through pseudo podia.
• Some of them can obtain food from light source ie, photoautotroph.

Virus --

• They are not alive, alive only inside host body
• Since, they are not considered as living cell. They are not classic as cellular or single cell or multiple. They are simply the protein shell which have tendency to infect other.
• Structure -- viruses have a protective protein coat know as capsid. It is made up of Phospholipid and proteins. Inside of virus, genetic material is located which may be Double stranded DNA or Single stranded RNA. Their body is divided into head, collar and tail.
• They are not autotroph ( not living)
• They are parasites.

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2. Three ways HIV is spread is through --

• Intravenous drug users
• Mother to child transmission
• Contact with infected blood

Multiple use of a single syringe to inject drug by absured can spread the disease.

If mother is infected, the virus travels through placenta into foetus.

Transfusion or contact with any contaminated blood helps the virus enter the host cell through body fluids.

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3. HIV completely destroys the immune system in any individual. The HIV virus infects CD4+ cells which play essential role in immunity.

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4. Reverse transcription

The retrovirus has the tendency to form HIV - DNA from an HIV - RNA.

Transcription is process where RNA is formed from DNA but here this process is reversed.