Variety Of Living Organisms & Structure Flashcards
(35 cards)
What is the structure of the bacterial nucleus?
Bacteria lack a nucleus and instead have a circular chromosome of DNA.
What makes up the cell walls of bacteria?
Bacterial cell walls are made of polysaccharides and proteins.
What are small extra circles of DNA in bacteria called?
Small extra circles of DNA in bacteria are called plasmids.
Can bacteria carry out photosynthesis, or how do they primarily obtain nutrients?
Some bacteria can carry out photosynthesis, but most feed off other living or dead organisms.
What is a common characteristic of bacteria in terms of size and structure?
Bacteria are microscopic single-celled organisms.
What role do bacteria play in ecosystems?
Bacteria are decomposers, breaking down organic matter.
Provide examples of rod-shaped bacteria.
Examples include Escherichia Coli (E. Coli) commonly found in animal intestines and Lactobacillus Bulgaricus.
Name a spherical bacterium and its role.
Pneumococcus is a spherical bacterium that acts as the pathogen causing pneumonia.
What are protoctists, and why are they sometimes called the ‘dustbin kingdom’?
Protoctists are single-celled organisms, sometimes referred to as the ‘dustbin kingdom’ because they are a mixed group that doesn’t fit into plants, animals, or fungi.
How do some protoctists, like Amoeba, resemble animal cells?
Some protoctists, such as Amoeba, have features similar to animal cells.
Which protoctists have chloroplasts and share similarities with plants?
Some protoctists, like Chlorella, have chloroplasts and exhibit characteristics more akin to plants.
Are all protoctists harmless, or do some act as pathogens?
Some protoctists, like Plasmodium, function as pathogens, causing diseases such as malaria.
Are viruses living organisms?
Viruses are not living organisms; they are small particles.
Which types of organisms can viruses infect?
Viruses are capable of infecting every type of living organism
How do viruses reproduce, and where does this process occur?
Viruses can only reproduce inside living cells, taking over the host’s genetic machinery.
Describe the cellular structure of viruses.
Viruses do not have a cellular structure
What types of nucleic acid do viruses contain?
Viruses contain either DNA or RNA, but not both.
Do viruses exhibit specific characteristics of living organisms, except for one?
Viruses do not carry out characteristics specific to living organisms except for reproduction.
How do viruses reproduce, and what is the key step in this process?
Viruses reproduce by entering host cells, taking over the genetic machinery, and using it to produce more virus particles.
Name examples of viruses and their associated effects.
Examples include Tobacco Mosaic Virus (discolors tobacco leaves), Influenza Virus (causes flu), and HIV (causes AIDS).
What is the role of the nucleus in cells, and what is it composed of?
The nucleus determines cell behavior and contains chromosomes made of DNA.
Describe the characteristics of the cytoplasm.
The cytoplasm is a jelly-like substance, primarily made of water and protein, where metabolic reactions occur.
What is the function of the cell surface membrane, and what is it made of?
The cell surface membrane is a partially permeable membrane, that controls substance movement (in & out) ; it is made of lipids and proteins.
Where does protein synthesis take place, and what are ribosomes made of?
Ribosomes are the sites of protein synthesis and are composed of RNA molecules and proteins.
