Bio Moc Exam preparation Flashcards
Discuss the evidence for the theory that mitochondria may have evolved from free-living prokaryotes by endosymbiosis. [3 marks]
c. they have their own «circular» DNA AND reproduce on their own ✔
d. they have «70s» ribosomes AND can manufacture «their own» proteins ✔
e. have organelle«s» similar to free-living prokaryotes ✔
Outline four types of membrane transport, including their use of energy. [4 marks]
a. simple diffusion is passive movement of molecules/ions along a concentration gradient ✔
b. facilitated diffusion is passive movement of molecules/ions along a concentration gradient through a protein channel «without use of energy» ✔
c. osmosis is the passage of water through a membrane from lower solute concentration to higher ✔ OWTTE
d. active transport is movement of molecules/ions against the concentration gradient«through membrane pumps» with the use of ATP/energy ✔
Draw the structure of a dipeptide. [3 marks]
a. two amino acids, one with NH2/NH3+end and one with COOH/COO– end ✔
b. peptide bond between C=0 and N—H correctly drawn ✔
c. «chiral» C with H and R group on each amino acid ✔
d. peptide bond labelled/clearly indicated between C terminal of one amino acid and N terminal of the second amino acid ✔
Explain the advantages of having both lipid and carbohydrate as energy stores in the human body.
[2 marks]
a. lipid is long-term energy storage
c. lipids store more energy «per gram»
Sketch a graph to show the effect of temperature on the activity of enzymes. [2 marks]
k
Explain enzyme–substrate specificity. [3 marks]
a. enzymes are proteins with specific 3-D geometry/shape
b. enzymes with active site that binds with the substrate/reactants
c. active site shape only allows it to bind with specific substrates «with complementary shapes»
Outline the function of codons. [1 mark]
«three bases on mRNA» coding for one amino acid «in a polypeptide» ✔
Determine the sequence of amino acids that could be translated from the sequence of mRNA. [1 mark]
met-ser-arg-arg
Determine the DNA base sequence transcribed to form this sequence of mRNA. [1 mark]
TAC TCG GCT TCC ATC GAC
Suggest a hypothesis that accounts for the slightly different meaning of some codons in a very limited number of organisms. [1 mark]
the genetic code is not «in fact» universal
State the type of reaction that removes water while linking amino acids together to form polypeptides.
[1 mark]
Condensation
Label the parts of the DNA diagram indicated by I, II, III and IV. [2 marks]
a. I. cytosine
b. II. sugar-phosphate/covalent/phosphodiester bond
c. III. phosphate
d. IV. deoxyribose
Explain how model making helped Watson and Crick to establish the structure of DNA. [2 marks]
b. built scale models of components of DNA
c. then attempted to fit them together in a way that agreed with the data «from separate sources»
Outline the role of the enzyme helicase in replication.
[1 mark]
separates strands/double helix (by breaking hydrogen bonds)
Outline the role of the enzyme DNA polymerase in replication.
[2 marks]
a. links nucleotides together to form a new strand of DNA
b. uses pre-existing strand of DNA as template
List three characteristics of eukaryotic homologous chromosomes. [3 marks]
b. carry the same sequence of genes ✔
c. «but» not necessarily the same alleles «of those genes» ✔
d. both are present when nucleus is in diploid state ✔
Using the following table, compare and contrast anaerobic cell respiration in yeasts and in humans. The first row has been completed
as an example. [3 marks]
k
Using the Punnett grid, explain how two parents can have children with any of the different ABO blood groups.
[3 marks]
k
State an application of plasmids in biotechnology. [1 mark]
to produce insulin/useful protein
Meiosis in humans produces cells that participate in fertilization. Outline the processes involved in meiosis.
[5 marks]
a. meiosis reduces a diploid cell into (four) haploid cell(s);
b. (during prophase I) homologous chromosomes pair up/synapsis;
c. chromatids (break and) recombine / crossing over
d. (metaphase I) (homologous chromosomes) at the equator of the spindle / middle of cell;
e. (anaphase I) (homologous) chromosomes separate and move to opposite poles;
Explain how evolution by natural selection depends on mutations. [4 marks]
a. mutations cause variation among organisms of same species/population;
b. some variations/mutations make individual more suited to its environment/way of life;
c. individuals that are better adapted survive and produce offspring;
d. individuals pass on genetic characteristics/mutation/variation to offspring;
The images show parts of plants belonging to two different phyla.
State the phylum of plant X and of plant Y.
X:
Y:
[2 marks]
X: Filicinophyta ✔
Y: Coniferophyta/Conifera/Gymnosperms ✔
Outline the types of evidence that can be used to place a species in a particular clade. [3 marks]
a. a clade is a group of organisms that have evolved from a common ancestor ✔
b. identify the base sequences of a gene ✔
c. identify amino acid sequence of a protein ✔
The cladogram includes four marsupial (non-placental mammal) families.
Deduce the family that is most closely related to the Diprotodontoidea.
[1 mark]
Vombatidae/wombats ✔
Distinguish between absorption of red, green and blue light by chlorophyll. [2 marks]
a. absorbs at blue and red (in high amount);
b. greatest absorption is of blue light / more blue light than red light absorbed;
c. low absorption of green light / green light is reflected;
Draw a graph to show the effect of increasing light intensity on the rate of photosynthesis. [1 mark]
k
Explain one way of directly measuring the rate of photosynthesis. [2 marks]
a. production of oxygen (which is a by-product of photosynthesis);
b. uptake of carbon dioxide (as carbon dioxide used as raw material for photosynthesis);
