Question

1.) Please give two similarities and two differences between prokaryotic and eukaryotic cells.

2.) Give a specific example of a prokaryotic organism.

3.) Since a plant has chloroplasts, why does it still need mitrochondria?

4.) Which plant organelle (chloroplasts vs. mitrochondria) helps to reduce the effect of global warming? Explain.

Answer 1

Similarities

Prokaryotic cell Eukaryotic cell

Nature of DNA ds circular ds circular

Histone protein absent absent

Ribosome type 70s 70s

Growth binary fission binary fission

Differences

True membrane bound nucleus absent present

DNA complexed with histone absent present

number of chromosome one more than one

mitosis & meiosis absent present

genetic recombination partial (unidirectional) crossing over

sterol in plasma membrane absent present

ribosome 70s 80s and 70s

unit membrane bound organelles absent present

cell wall peptidoglycan cellulose in plant and chitin in fungi

example of prokaryotic organism : Largest known bacterium -Thiomargarita namibiensis

smallest bacterium Mycoplasma pneumoniae

Plants perform two vital functions photosynthesis which is fixation of solar energy to chemical energy in the form of glucose. This process takes place in chloroplasts. At the same time plants need energy (infact all the living organisms need energy) for their growth and all metabolic processes. This energy is obtained by using glucose and oxygen. This process is known as respration which takes place in mitochiondria. Therefore both these cell organells are required by the plants.

Photosynthetic organisms like chloroplasts absorb billions of tons of CO2 every year!

Most of this carbon returns to the atmosphere via cellular respiration, but much of it remains locked in large tracts of forests and in long-term storage as fossil fuels buried deep under the Earth’s surface