Biology 2.1.5: Other Features Of Eukaryotic Cells

Question 1

what is the structure of the centriole?

Answer 1

hollow fibres of microtubules (made of tubulin)
two centrioles at right angles to one another to form centrosome.
not found in flowering plants or algae.

Question 2

what organelles do not have membranes?

Answer 2

ribosomes, cytoskeleton, centrioles

Question 3

what is the function of centrioles?

Answer 3

used in the formation of cilia and udunpodia: centrioles multiply beneath cell surface membrane, microtubules sprout outwards from each centriole to form these.
spindle fibres made from tubulin forms from centriole and pulls chromosomes to opposite ends of cell during cell division.

Question 4

what is the structure of ribosomes?

Answer 4

20 nm in diameter, made of ribosomal RNA + made in nucleolus: 80S ribosomes are found in eukaryotic cells, 70S ribosomes are found in prokaryotes, mitochondria + chloroplasts.

Question 5

what is the function of ribosomes?

Answer 5

the site of translation in protein synthesis.
ribosomes bound to RER synthesis proteins that leave the cell.
ribosomes in cytoplasm are the site of assembly of proteins used within the cell.