• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Persuade a creationist that the endosymbiont theory is correct.

Extracts from this document...


Persuade a creationist that the endosymbiont theory is correct. all life forms on Earth are made of cells. Eukaryotic cells have a cell nucleus separated from the rest of the cell contents (the cytoplasm) by a nuclear membrane. The nucleus contains DNA on chromosomes, whilst within the cytoplasm are distinct membrane-bounded organelles, which perform specific tasks. The more ancient prokaryotic cells on the other hand, (bacteria and Cyano-bacteria) carry their genetic material in simple strands of DNA that is not separated from the cytoplasm by a nuclear membrane. They reproduce asexually. Eukaryotic cells reproduce sexually, mixing genes between individuals and passing genetic variations to their offspring. Sexual reproduction allows more genetic combinations, so only not can eukaryotic cells be larger and more complex than prokaryotic cells, but also their ability for sexual reproduction made it more plausible for multi-cellular plants and animals to evolve. Eukaryotic cells are therefore the key to the evolution of the diversity of plant and animal life on our planet. The new techniques of functional genomics, now enabling the sequencing of the entire genomes of organisms. The new science, often automated, provides scientists with vast quantities of data. ...read more.


This idea was based on observations of cell structure, the biochemistry taking in the organelles and the fact that mitochondria and chloroplasts had unique genes that did not appear in the cell nucleus. It was an interesting theory that took over seven decades to become respectable. In the 1960's, the biologist Lynn Margulis put forward what was to become known as the Endosymbiont Hypothesis. In 1970 her book "Origin if Eukaryotic Cells" was published, followed by "Symbiosis in Cell Evolution" in 1981. Although now accepted as mainstream, the idea was treated with scepticism and even ridicule for several years, according to Professor John Allen: - "To a student in the 1960's and 1970's it was still a hypothesis. It was still a bit wacky, still on the fringe. People might want to talk about it over coffee, but you wouldn't set examination questions on it, because it wasn't real! It's mainstream stuff now. These things were once free-living bacteria. It's quite inconceivable that it could be otherwise. And it raises questions: what sort of bacteria and what evolutionary forces were at work? And why did they lose so many genes? ...read more.


During the history of plant cells, complex rearrangements of the genes responsible for photosynthetic machinery have taken place. These have included the loss and gain as well as the transfer of genetic material between the original endosymbionts Co-evolution took place of genes in the organelles and in the nucleus. As a result, genes and intracellular signalling are very specific, tailored to each individual partnership. Consequently, organelle changes between even closely related species can result in disturbance of the intra cellular genetic balance because of incompatibility. Throughout the evolution of plastids, genes were transferred to the nucleus of the host cell with major consequences for the regulation of gene expression. Although the genes themselves have been lost to the nucleus, the plastid retains a role in the manufacturing of proteins necessary for photosynthesis, the plastids and the nucleus is involved in regulating the expression a set of nuclear genes that encode proteins required for photosynthesis and related processes. Two and a half billion years of co-existence and co-evolution are summed up by a theory known as endosymbiosis. It explains the origin of organelles seen inside eukaryotic cells, notably mitochondria and chloroplasts. In a nutshell, the endosymbiotic theory is that mitochondria evolved from bacteria living within their host cell. Chloroplasts evolved from endosymbiotic cyanobacteria; that is from prokaryotic organisms able to synthesise organic constituents from inorganic sources. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Genetics, Evolution & Biodiversity section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Genetics, Evolution & Biodiversity essays

  1. Marked by a teacher

    An Investigation into the Mitotic Nuclear Division of Allium Sativum Root Tip Cells, and ...

    5 star(s)

    One possible suggestion of an explanation of this occurrence is that the wide range of intercellular transport relies heavily on the concept of the provision of ATP to the cell; a theory that is linked closely with the next point.

  2. Recombinant DNA, genetically engineered DNA prepared in vitro by cutting up DNA molecules and ...

    congenital disorder, and the DNA pattern of cells from the fetus is compared. In many situations the disease status of the fetus can be determined. Currently this technique is applicable to thalassemias, Huntington's disease, cystic fibrosis, and Duchenne's muscular dystrophy (see Genetic Disorders).


    improvement done to my experiment, but if any possible improvement could be done, what I would do is leave the tubes inside the water bath longer to have beter effect to substances in tube and I would leave tubes in ice to have the better effect on tubes.

  2. Cell Theory - Discuss the theory that living organisms are composed of cells.

    1.2 Prokaryotic Cells (1h) 1.2.1 Draw the generalized prokaryotic cell as seen in electron micrographs. SEPARATE PAPER 1.2.2 State one function of the following: cell wall, plasma membrane, mesosome, cytoplasm, ribosomes, and naked DNA. * Cell wall- for strength/ maintain shape/ protection/prevents bursting due to osmosis * Cell membrane- for

  1. HSC maintaining a balance notes

    III) Effect of Environment 1. One group of wheat plants grown under light 2. Another without light 3. Water, nutrients and other factors constant. Results: plants without light were significantly shorter. 4. Changes in DNA 4. a) DNA Replication Replication is the process where an exact copy of DNA is made during meiosis and mitosis.

  2. Investigating what effect varying the concentration of copper sulphate has on the enzyme Catalase ...

    After the optimum temperature the enzyme denatures. This graph shows how pH affects the activity of an enzyme. It shows that the height of enzyme activity happens at an optimum pH and any lower or higher than that pH the enzyme activity decreases because of the enzyme denaturing.

  1. Chromosomes and DNA

    * Some energy is used in respiration for movement, transport and other maintenance activities, ending up as wasted heat. * The increase in biomass in growth or the production of offspring is available to the next trophic level. The biggest loss of energy is from the sun's energy to plant tissues in photosynthesis.

  2. Free essay

    Outline the impact on the evolution of plants and animals of: ...

    * Studies of a wide range of animals have found that many possess similar molecules, which is further evidence of common ancestry, * Some biochemical processes are the same for all living cells. * Certain proteins are commonly found in a large number of organisms.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work