Answer:
The formula for calculating population density is Dp= N/A. In this equation, Dp is the density of population, N is the total population as a number of people, and A is the land area covered by that population.
Explanation:
a statistic that tells you how many people live in a certain area. ... density is reported in square miles or kilometers, and may or may not include bodies of water. This type of measurement is called arithmetic density, and is reported as the total number of people per land.
Answer:
23, haploid
Explanation:
there are 23 chomrosomes in both a egg and sperm cell
this makes them haploid as they have a single set of unpaired chromosomes
hope this helped
Traits that are sex-linked are carried on either the X or Y chromosome. If they are carried by a female, they are X-linked traits, and if they are carried by a male, they are Y-linked traits.
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.
