They are divided into two main groups, Archaea (Archaeobacteria) and Bacteria (Eubacteria). Prokaryotes have no nucleus, and the genetic material (DNA) is less organized in chromatin and chromosomes than it is in eukaryote unicellulars.
- 1 What are three environments where methane producing archaea have been found?
- 2 How do the structures of bacteriophages help them infect host cells?
- 3 What are 2 ways that viruses that infect eukaryotes enter their host cells?
- 4 What must viruses do before they can reproduce?
- 5 What are the two main groups of archaea?
- 6 What are the 3 major groups of archaea?
- 7 What type of genetic material is present in bacteriophage?
- 8 Which part of the bacteriophage contains genetic material?
- 9 When the bacteriophage DNA becomes part of the bacterial chromosome?
- 10 What 2 components do all viruses contain?
- 11 How do viruses infect prokaryotic cells?
- 12 Are bacteria and viruses prokaryotes or eukaryotes?
- 13 Are viruses asexual?
- 14 Are viruses dead or alive Khan Academy?
- 15 Is a virus alive?
What are three environments where methane producing archaea have been found?
They have been found thriving inside the digestive tracts of cows, termites, and marine life where they produce methane. They live in the anoxic muds of marshes and at the bottom of the ocean, and even thrive in petroleum deposits deep underground.
How do the structures of bacteriophages help them infect host cells?
How do the structures of bacteriophages help them infect host cells? Tail and spikes help attach the virus to the host cell, the tail releases enzymes to break down the bacterial cell wall. The tail core breaks the cell wall and injects the phage’s DNA, the phage injects the genes into the host cell’s cytoplasm.
What are 2 ways that viruses that infect eukaryotes enter their host cells?
Enveloped viruses also have two ways of entering cells after binding to their receptors: receptor-mediated endocytosis and fusion. Many enveloped viruses enter the cell by receptor-mediated endocytosis in a fashion similar to some non-enveloped viruses. On the other hand, fusion only occurs with enveloped virions.
What must viruses do before they can reproduce?
A virus is a tiny, infectious particle that can reproduce only by infecting a host cell. Viruses “commandeer” the host cell and use its resources to make more viruses, basically reprogramming it to become a virus factory. Because they can’t reproduce by themselves (without a host), viruses are not considered living.
What are the two main groups of archaea?
Most of the culturable and well-investigated species of archaea are members of two main phyla, the Euryarchaeota and Crenarchaeota. Other groups have been tentatively created, like the peculiar species Nanoarchaeum equitans, which was discovered in 2003 and has been given its own phylum, the Nanoarchaeota.
What are the 3 major groups of archaea?
There are three major known groups of Archaebacteria: methanogens, halophiles, and thermophiles. The methanogens are anaerobic bacteria that produce methane.
What type of genetic material is present in bacteriophage?
Bacteriophage have either DNA or RNA as their genetic material, in either circular or linear configuration, as a single- or a double-stranded molecule.
Which part of the bacteriophage contains genetic material?
Like all viruses, phages are simple organisms that consist of a core of genetic material (nucleic acid) surrounded by a protein capsid. The nucleic acid may be either DNA or RNA and may be double-stranded or single-stranded.
When the bacteriophage DNA becomes part of the bacterial chromosome?
A prophage is a bacteriophage (often shortened to “phage”) genome inserted and integrated into the circular bacterial DNA chromosome or exists as an extrachromosomal plasmid. This is a latent form of a phage, in which the viral genes are present in the bacterium without causing disruption of the bacterial cell.
What 2 components do all viruses contain?
The simplest virions consist of two basic components: nucleic acid (single- or double-stranded RNA or DNA) and a protein coat, the capsid, which functions as a shell to protect the viral genome from nucleases and which during infection attaches the virion to specific receptors exposed on the prospective host cell.
How do viruses infect prokaryotic cells?
Transduction is the process by which a virus transfers genetic material from one bacterium to another. Viruses called bacteriophages are able to infect bacterial cells and use them as hosts to make more viruses.
Are bacteria and viruses prokaryotes or eukaryotes?
Short story: Human cells are eukaryotic which means they are more complicated, bacteria cells are prokaryotic which means they are simpler and viruses are not even cells at all, they are just genetic material in a protein shell.
Are viruses asexual?
Viruses can’t reproduce on their own. They need a host cell in order to be able to do it. The virus infects a host cell and releases its genetic material into it.
Are viruses dead or alive Khan Academy?
So were they ever alive? Most biologists say no. Viruses are not made out of cells, they can’t keep themselves in a stable state, they don’t grow, and they can’t make their own energy. Even though they definitely replicate and adapt to their environment, viruses are more like androids than real living organisms.
Is a virus alive?
Many scientists argue that even though viruses can use other cells to reproduce itself, viruses are still not considered alive under this category. This is because viruses do not have the tools to replicate their genetic material themselves.