Plants use sugars and mineral from the sail to make food and use the energy from the sun to create the sugars used to make the food. They also use the carbon dioxide from the air to help create the food.
Answer:
- Based on this information you come to the conclusion that you have been able to identify in these cells the structure of <em>microfilaments</em> or <em>actin filaments</em>.
- <em>Oviductus oblatus</em> are indeed eukaryotic cells
Explanation:
In eukaryotic cells, the cytoskeleton is composed of three well defined filamentous structures: microtubules, microfilaments, and intermediate filaments. Each of these filamentous structures is a <u>polymer of proteinic subunits</u> united by weak, not covalent connections.
The microfilaments are the thinnest of the three structures. They have a <u>diameter of 7 nanometers</u> and are <u>composed of many proteinic monomers</u> united. This monomeric protein is called actin. Many monomers get combined to form a structure that assembles a double helix.
Due to the fact that these microfilaments are made of actin monomers, they are also known as actin filaments.
Actin filaments have directionality which means that their extremes have different structures.
In eukaryotic cells, genes that codify for actin microfilaments are highly conserved in all organisms, which is why <u>they are often used as molecular markers</u> for different studies.
1. The correct answer is: The viral envelope proteins interact with CD4 and a co-receptor on the cell membrane.
Binding and entering the host cell are the first steps of the HIV virus infection. So, these steps play a major role in determining the ability of HIV to degrade the human immune system. Binding of HIV to CD4+ T lymphocytes (express chemokine receptors CCR5 and CXCR4 called co-receptors) triggers the fusion of the viral and host cell membranes, initiating infection (viral core gets into the cytoplasm).
Attachment of the virion can be:
• Nonspecific-envelop protein of the virus (Env) binds to cell-surface heparan sulfate proteoglycans
• Specific-Env binds to integrin.
2. The correct answer is: Activation of the host cell by cytokines, growth factors, or antigens.
After the viral capsid enters the cell, single-stranded RNA genome is released from the attached viral proteins and copied it into a complementary DNA (cDNA) molecule thanks to an enzyme called reverse transcriptase. Next step is the integration of the viral DNA into the host cell's genome. This process is done by another viral enzyme called integrase. The integrated DNA is transcribed into RNA and then translated into proteins that will help the package of new viruse particles.
3. The answer is: false
Reverse transcriptase is an enzyme that catalyzes the formation of DNA from an RNA template. Since the genome of the virus (HIV) is single stranded RNA, reverse transcriptase copies it into a complementary DNA (cDNA) molecule. Thanks to this enzyme, formed cDNA can be integrated into host’s genome. Because of this proprety, antiretroviral drugs used to treat HIV infection work as reverse-transcriptase inhibitors.
Answer:
A.) dandelions with seeds dispersed by the wind
Explanation:
