Question

4. Development of organelles Aa Aa 3 Modern eukaryotic cells are very complex and have many features that allow them to function efficiently. These complexities took a very, very long time to evolve and likely progressed as a series of small improvements that were naturally selected. For example, modern eukaryotic cells have internal membranes surrounding their organelles and the nucleus. This arrangement likely arose when the cellular membranes of some ancient bacterial cells accidentally folded to become internal membranes. Which of these statements describes an accurate reason why folded, internal membranes are advantageous? Folded membranes have a less complex lipid structure than external membranes. Surrounding the DNA with a membrane helps protect the DNA from foreign genetic material, such as viral genetic material. Internal membranes contain more minerals. What modern-day evidence supports this idea of how internal cell membranes arose? The gene that causes membrane folding does not occur in bacteria. Some modern bacteria have internal membrane-enclosed compartments. When a cell is exposed to new proteins in its environment, these proteins are often incorporated into both the external and internal membranes.

Answer 1

As there are 4 questions I divide it as follows:

a) In the development of organelles, eukaryotic cells have internal membranes surrounding their organelles and nucleus.The statement which describes an accurate reason why folded internal mebbranes are advantageous is second one as it says surrounding the DNA with a membrane helps protect the DNA from foreign genetic material, such as viral genetic material. because it compartmentalize or localize the intracellular metabolic processes The internal membranes facilitate cellular processes by minimising competing interaction and increasing surface area where enzymatic reactions happens. it also help to keep enzme and other materials to be in one place. so in eukaryotes they have complex organelle systems and thus it allows them to grow into larger organisms.

b)The modern day evidence support this idea of how internal membranes arose is second one which says some modern bacteria have internal membrane enclosed compartments. We get evidence from endosymbiotic hypothesis which states that mitochondria and bacteria arose from bacteria entering a eukryotic cell to form a symbiotic relationship, it is based on the similarity in function of mitochondria with purple bacteria as they use krebs cycle and oxidative phosphorylation for ATP production. Also chloroplasts are very similar to photosynthetic bacteria as they have same chlorophylls structurally. they have similarity in DNA, ribosomes and protein synthesis also.

c) Cyanobacteia is a group of modern day bacterial cells which are similar to structure and function of mitochondria. They are typically prokaryotic in structure and carry out oxygenic photosynthesis.

d) Here the option first is correct.When a cell divide into two cells, new mitochondria divide and replicate on their own, at a different time from rest of the cell. As the mitochondria have their own DNA and divide independently of the cell.The mitochondrial DNA is inherited by one's mother.

Thanks!