Bio - Chapter 2 (Part 2) Flashcards
What are 5 types of archaea?
- Methanogens
- Extreme halophiles
- Extreme thermophiles
- Psychrophiles
- Acidophiles
What type of environment do methanogens live in? (3)
- Low oxygen
- Anaerobic
- High methane
What time of environments to extreme halophiles live in? (2)
- High salt
2. Saline environment
What type of environments do extreme thermophiles live in?
Extremely hot environment
- 70 to 90 dec C
What type of environments do psychrophiles live in?
Extremely cold
- -10 to -20 deg C
What types of environments do acidophiles live in?
Very acidic
What are 2 characteristics of a bacteria cell?
- Plasmids
2. Capsule
Plasmids
Small loop of DNA often found in prokaryotic cells that contain a small umber of genes
- transferred in conjugation
Capsule
An outer layer on some bacteria, provides some protection for the cell
- reduces water loss, resists high temperature and helps keep out viruses and antibiotics
What are 6 different shapes of bacteria?
- Cocci
- Bacill
- Sprill
- Diplo
- Strepto
- Styphlo
What shape is cocci?
Round
- resists drying
What shape is Bacill?
Rod-shaped
- increased surface area for nutrient absorption
What is the shape of sprill?
Sprial shaped
- easier movement, locomotion
Diplo
Pair
Strepto
Chain
Styphlo
Cluster
- similar to grapes
What are 2 types of eubacteria reproduction?
- Binary fission
- asexual - Conjugation
- sexual
What are 3 advantages to binary fission?
- Exponential growth
- Only one parent needed
- Conserves energy
What are 3 disadvantages to binary fission?
- No genetic diversity
- Higher risk for extinction
- Rapid reproduction leads to high mutation rate and competition
How does conjugation work? (2)
- A pilus is formed between 2 cells
2. DNA is transferred from one cell to the other
What is an advantage to conjugation?
It can increase the likelihood that cells could adapt to changing conditions
What is transformation?
When a cell takes in DNA from the environment and uses it
What is horizontal gene transfer?
It is any process in which one species gets DNA from a different species
What is an advantage to horizontal gene transfer?
It allows for genetic variation which increases likelihood of species resisting change
What are 4 disadvantages of horizontal gene transfer?
- Slower
- Requires more energy
- Requires a partner
- Could obtain bad DNA
Endospore formation (dormant phase)
Bacteria develop a small, seed like structure consisting of a tough outer coating surrounding the DNA and a small amount of cytoplasm
What happens with endospore formation in good conditions?
Endospore loses coat and bacteria returns to normal growth
What are 2 advantages to endospore formation?
- Likely have a longer lifespan
2. Can resist unfavourable conditions
What are 3 disadvantages to endospore formation?
- Slow
- No growth
- No reproduction
Serial endosymbiosis
Specifies the relationship between organisms which live on or within a mutually beneficial relationship
- the process through which eukaryotic cells evolved
Endosymbiont
The cell that lives within another/the host cell
How do ancestral prokaryote cells form nucleus’s?
Through infolding of plasma membrane
What was an mitochondria ancestor?
It was an aerobic heterotrophic prokaryote, was engulfed and became the endosymbiont within the larger anaerobic prokaryote
What was a chloroplast ancestor?
It was a photosynthetic prokaryote that was engulfed and became the endosymbiont
What are 5 pieces of evidence of the ancestors mitochondria and chloroplast?
- Mitochondria and chloroplast have their own internal DNA
- and its circular - Both have genes similar to those of bacteria, their ribosomes are similar too
- Both divide not by mitosis, but by binary fission like bacteria
- Both are appropriate sizes to be descendants of bacteria and both have membranes
- Both move freely about cell
What are 4 characteristics for protista?
- Extremely diverse characteristics
- First eukaryotes
- Most aquatic organisms
- Most unicellular (some are multicellular)
What does the name protozoa mean?
First animal
What are 3 examples of protozoa?
- Euglenoids
- Ciliates
- Apicomplexa
How do more organsims from the protozoa group eat their food?
By engulfing it
Algal protists
Form the base of the food chain for most aquatic habitats
What are 2 examples of algal protists?
- Diatoms
2. Red algae
What are slime moulds?
They are decomposers in forested ecosystems
What are water moulds?
They are decomposers in algae, leaves, etc in aquatic ecosystems
What 2 generations make up the life cycle?
- Haploid
2. Diploid
Haploid
One set of chromosomes or genetic material
- gametophyte
Diploid
2 sets of chromosomes
- sporophyte
When to gametophytes fuse and what do they create?
- They fuse during fertilization
- They develop into sporophytes
- then the cycle repeats
Euglenoids (3)
- Unicellular autotrophs
- 2 flagella for moving
- Outer surface covered in stiff proteins
Ciliates (3)
- Unicellular heterotrophs
- Many cilia
- No cell wall
Apicomplexa (3)
- Unicellular heterotrophs
- No cell wall
- All are parasites of animals
Diatoms (3)
- Unicellular autotrophs
- Moving by gliding
- Covered by glass like silica shells
Amoebas (3)
- Autotrophs
- Some have hard outer skeletons
- Move by extensions of the cytoplasm called pseudopods
Slime moulds (3)
- Heterotrophs, decomposers
- Life cycles have unicellular and multicellular stages
- Move with flagella or pseudopods
Red algae (3)
- Almost all multicellular
- autotrophs - No cilia or flagella
- Cell walls made of cellulose