Honors Biology SAT Presentation:
Microorganisms
For my honor's portion of my Biology class I read and annotated the Biology SAT book. With the information I learned I created two presentations in each semester on the chapter/section of my choice.
Explanations behind the phrases and terms in this presentation
Microorganisms Script
Slide 3:
Protists (pro-tist) are eukaryotes (you-kah-rye-oat) and contain organelles and a true nucleus. Eukaryotic cells are different from prokaryotic (pro-care-E-oat) cells in that they have a true nucleus. With a true nucleus there is a nuclear membrane within the cell.
Most Protists are unicellular, but some form colonies.
Algae are a truly multicellular protists.
Protists have their own “kingdom” called Kingdom Protista (pro-tist-A). It can be divided into three main groups: Protozoa (pro-toe-zo-ah) (animal like protists), algae (plant like protists), and a few fungus-like protists.
Image: phylum protista...picture of one of the different types of protozoans
Slide 4:
Most fungi are multicellular eukaryotes. That means they are made up of many cells, and their cells have a nuclei and other organelles.
Some fungi are multinucleate (multi-new-cle-ate), their cells are not separated by cells walls and seem to be one giant cell with many nuclei.
Fungi do not produce their own food, because they cannot photosynthesize, because they do not have chloroplasts.
This classifies them as heterotrophs, which makes them absorptive feeders. They secrete hydrolytic enzymes that digest their food outside their bodies. This predigested food is easy for the fungi to absorb. Many fungi are decomposers, feeding on dead or decaying material, helping it breakdown.
Image: Mold Growing
Slide 5:
Fungi reproduces in several different ways.
Asexual spores: These spores are seeds that can drop off the fungus and grow a new organism.
Sexual Spores: Fungi can produce sexual spores, similar to sperm and ova, that combine to form a new organism.
Vegetative Growth: A portion of the fungus breaks off and forms a new fungus.
Budding: A new fungus grows off the side of the old fungus. An example of budding would be the way yeast reproduces.
Slide 6:
Bacteria are single-celled organisms. They have no nuclei, and no membrane-bound organelles this classifies them as prokaryotes.
Because they have no nuclei their DNA is found in the cytoplasm.
Bacterial DNA is usually found as a single, circular chromosome. It’s still double-stranded, to protect the DNA from damage, the ends of the strand are joined in a circle.
Unlike fungi, bacteria has a cell wall, it is made up of proteins and sugars, or peptidoglycan.
Slide 7:
Some bacteria, the cyanobacteria, can perform photosynthesis, which means that they’re autotrophs.
Most bacteria cannot perform photosynthesis, and they are known as obligate aerobes.
Some bacteria are poisoned by oxygen, these are known as obligate anaerobes.
There are some bacteria that will use oxygen if it’s available, but can survive by fermentation if oxygen is not available, they are known as facultative anaerobes.
Slide 8:
A Virus isn’t really considered a cell, and it’s not technically considered to be alive.
It only has two components; a coat of capsid, or the entirely protein shell of the virus, and inside the coat is the genome, or nucleic acid. Depending on the virus the genome could be DNA or RNA
Viruses have none of the machinery required to reproduce themselves. They can only reproduce with the help of another cell, and use that cell’s enzymes.
All cells can be infected by viruses.
Slide 9:
Begins with two steps:
Attachment: The virus attached itself to the host cell. This is a specific interaction between the virus and the host cell: a virus can attach only to its
particular host.
Infection: The virus injects its genome into the host cell.
The next step can go in two possible directions, the Lytic cycle, or the Lysogenic cycle.
In the lytic cycle the viral genome is first transcribed and translated to make viral proteins. The host DNA polymerases then replicate the viral genome, and the viral genomes are packaged into the new viral capsids. Finally the host is broken open. In this process the host cell is harmed considering viruses to be parasites.
In the lysogenic cycle is inserted into the host genome to remain dormant. This virus can lay dormant for years until the host cell experiences some sort of stress allowing the virus to enter the lytic cycle.
Slide 3:
Protists (pro-tist) are eukaryotes (you-kah-rye-oat) and contain organelles and a true nucleus. Eukaryotic cells are different from prokaryotic (pro-care-E-oat) cells in that they have a true nucleus. With a true nucleus there is a nuclear membrane within the cell.
Most Protists are unicellular, but some form colonies.
Algae are a truly multicellular protists.
Protists have their own “kingdom” called Kingdom Protista (pro-tist-A). It can be divided into three main groups: Protozoa (pro-toe-zo-ah) (animal like protists), algae (plant like protists), and a few fungus-like protists.
Image: phylum protista...picture of one of the different types of protozoans
Slide 4:
Most fungi are multicellular eukaryotes. That means they are made up of many cells, and their cells have a nuclei and other organelles.
Some fungi are multinucleate (multi-new-cle-ate), their cells are not separated by cells walls and seem to be one giant cell with many nuclei.
Fungi do not produce their own food, because they cannot photosynthesize, because they do not have chloroplasts.
This classifies them as heterotrophs, which makes them absorptive feeders. They secrete hydrolytic enzymes that digest their food outside their bodies. This predigested food is easy for the fungi to absorb. Many fungi are decomposers, feeding on dead or decaying material, helping it breakdown.
Image: Mold Growing
Slide 5:
Fungi reproduces in several different ways.
Asexual spores: These spores are seeds that can drop off the fungus and grow a new organism.
Sexual Spores: Fungi can produce sexual spores, similar to sperm and ova, that combine to form a new organism.
Vegetative Growth: A portion of the fungus breaks off and forms a new fungus.
Budding: A new fungus grows off the side of the old fungus. An example of budding would be the way yeast reproduces.
Slide 6:
Bacteria are single-celled organisms. They have no nuclei, and no membrane-bound organelles this classifies them as prokaryotes.
Because they have no nuclei their DNA is found in the cytoplasm.
Bacterial DNA is usually found as a single, circular chromosome. It’s still double-stranded, to protect the DNA from damage, the ends of the strand are joined in a circle.
Unlike fungi, bacteria has a cell wall, it is made up of proteins and sugars, or peptidoglycan.
Slide 7:
Some bacteria, the cyanobacteria, can perform photosynthesis, which means that they’re autotrophs.
Most bacteria cannot perform photosynthesis, and they are known as obligate aerobes.
Some bacteria are poisoned by oxygen, these are known as obligate anaerobes.
There are some bacteria that will use oxygen if it’s available, but can survive by fermentation if oxygen is not available, they are known as facultative anaerobes.
Slide 8:
A Virus isn’t really considered a cell, and it’s not technically considered to be alive.
It only has two components; a coat of capsid, or the entirely protein shell of the virus, and inside the coat is the genome, or nucleic acid. Depending on the virus the genome could be DNA or RNA
Viruses have none of the machinery required to reproduce themselves. They can only reproduce with the help of another cell, and use that cell’s enzymes.
All cells can be infected by viruses.
Slide 9:
Begins with two steps:
Attachment: The virus attached itself to the host cell. This is a specific interaction between the virus and the host cell: a virus can attach only to its
particular host.
Infection: The virus injects its genome into the host cell.
The next step can go in two possible directions, the Lytic cycle, or the Lysogenic cycle.
In the lytic cycle the viral genome is first transcribed and translated to make viral proteins. The host DNA polymerases then replicate the viral genome, and the viral genomes are packaged into the new viral capsids. Finally the host is broken open. In this process the host cell is harmed considering viruses to be parasites.
In the lysogenic cycle is inserted into the host genome to remain dormant. This virus can lay dormant for years until the host cell experiences some sort of stress allowing the virus to enter the lytic cycle.
For extra practice!
Test your knowledge on microorganisms
Microorganisms Quiz
Check off the correct answer, or fill in the blank.
1. Prokaryote [( )do ( )do not] have a nucleus.
2. Protists [( )do ( )do not] have a nucleus.
3. Fungi are classified as [( )eukaryotes ( )prokaryotes].
4. Bacteria [( )do ( )do not] have cell walls.
5. A viral _________ is made of protein.
6. Bacteria that are perfectly happy in the presence OR absence of oxygen are called _________________.
7. [( )Some ( )All] fungi are eukaryotes.
8. Yeast are [( )eukaryotes ( )Prokaryotes] that reproduce by ________.
9. Fugic [( )can ( ) cannot] photosynthesize.
10.Bacteria are classified as [( )prokaryotes ( )eukaryotes] and therefore
[( )do ( )do not] have nuclei.
Check off the correct answer, or fill in the blank.
1. Prokaryote [( )do ( )do not] have a nucleus.
2. Protists [( )do ( )do not] have a nucleus.
3. Fungi are classified as [( )eukaryotes ( )prokaryotes].
4. Bacteria [( )do ( )do not] have cell walls.
5. A viral _________ is made of protein.
6. Bacteria that are perfectly happy in the presence OR absence of oxygen are called _________________.
7. [( )Some ( )All] fungi are eukaryotes.
8. Yeast are [( )eukaryotes ( )Prokaryotes] that reproduce by ________.
9. Fugic [( )can ( ) cannot] photosynthesize.
10.Bacteria are classified as [( )prokaryotes ( )eukaryotes] and therefore
[( )do ( )do not] have nuclei.
Lastly...check your answers!
1. Do Not
2. Do
3. Eukaryotes
4. Do
5. Capsid
6. Facultative Anaerobes
7. All
8. Eukaryotes / Budding
9. Cannot
10.Prokaryotes / do not