Joaquin tells his science class that galaxies consist of gas, dust, and many planets. What is the most important component of galaxies Joaquin is missing in his description? asteroids

comets

constellations

stars

- Obligate anaerobes: B

- Facultative anaerobes: A

- Aerotolerant anaerobes: D

- Obligate aerobes: C

Explanation:

Obligate anaerobes are microorganisms that dead in normal atmospheric oxygen (O2) levels (around 21%). Some examples of obligate anaerobes are procaryotic bacteria such as Clostridium, Fusobacterium, Actinomyces and Peptostreptococcus.  Facultative anaerobes are organisms that can grow without O2 and produce energy by fermentation, but they can produce more energy (ATP) by the aerobic respiration mechanism. Facultative anaerobes include both prokaryotic (e.g., Escherichia coli) and eukaryotic (e.g., Saccharomyces cerevisiae) organisms. Aerotolerant anaerobes are microorganisms that can live in O2 atmospheric conditions, but they use fermentation as cellular mechanism to produce energy (ATP). Some examples of aerotolerant anaerobes are lactobacilli and streptococci (bacteria) found in the oral microbiota. Finally, obligate aerobes are organisms that can grow only in normal O2 conditions and metabolize foods through cellular respiration, a process more energetically efficient than fermentation. An example of an obligate aerobe is the human species.