Biology Weak Questions Flashcards
Name two biological molecules that can be coded for by a gene (do not include a polypeptide or protein in your answer)
rRNA, tRNA, mRNA
Explain why the damage to the cells lining the ileum reduces absorption of the products of digestion and why this reduces absorption of water
-reduced surface area/fewer co-transport/carrier/channel proteins
-decreased water potential in ileum/lumen or increases water potential in cells
-so water moves out of the cells into ileum by osmosis or less/no water moves into cells/out of ileum by osmosis
Describe how the anti-toxin antibody would be digested
-peptide bonds hydrolysed
-endopeptidases break internal bonds
-exopeptidase break terminal bonds
-dipeptidases break dipeptides to amino acids
Suggest what the student should have done when she saw that the shape C, block 2 was damaged
REPEAT test with an undamaged block
Describe how gas exchange occurs in single-felled organisms and explain why this method canno5 be used by large, multicellular organisms
-Diffusion
-large organisms have smaller surface area to volume ratio
-diffusion pathway would be too long OR diffusion too slown
Explain the importance of the xylem being kept open as a continuous tube
-water column
-cohesion from H bonds between all water molecules
-evaporation/transcription creates tension
The cells in the drawing A can be identified as those treated as those treated with MiTMAB explain why
-nuclear or cells at teleophase
-cytokinesis prevented OR stopped new membrane from OR Stopped cytoplasm did using
Explain how sucrose-transport proteins in leaf cells enable the production of pressure gradient in the phloem
-sucrose co-transported into phloem
-causes decrease in water poetential
Water enters by osmosis
Potato plants with fewer sucrose-transport proteins produce fewer potatoes and accumulate sugars in their leaves
-carbohydrates made by photosynthesis
-less sucrose transported into phloem at leaf
Give two reasons why glucose uptake by muscle cells increases significantly during exercise
1) increased numbers of glucose transporter proteins in the membrane-facilitated diffusion
2) increased respiration to provide more ATP for muscle contraction
State one feature that shows the images in Figure 5 were taken with an electron microscope and not an optical microscope
-higher resolution
-ribosomes visible
The rate of translation is increased in T cells activated by antigens. Describe the role of tRNA in translation
-anticodon binds to codon on mRNA
-carries amino acid to the ribosomes
Outline similarities in, and the differences between the structures of DNA and RNA molecules
Similarities
-both polymers of nucleotides
-both have Pentose,base and a phosphate
-cytosine, guanine and adenine
-have phosphodiester bonds
Differences
-deoxyribose v ribose
-thymine v uracil
-long v short
-double helix v single stranded
Outline the similarities, and the differences between the structures of chloroplast and mitochondria
Similarities
-double membrane
-both contain (circular DNA)
-both contains ribosomes
Differences
-thykloids/lamelle/grana v cristae
-stoma v matrix
-pigments v no pigments
-strachvgrans v no starch grains
What is C1?
The concentration that we have got in the stick solution
