Bio Q- Paper 2 Flashcards
How would an increase in the conc of co2 in the atmosphere cause an increase in air temp
- traps heat / energy or (long- wavelength / IR) radiation
- less loss of heat
- insulates
Give two possible effects of an increase in global air temp on living organisms
• (some) plants grow faster / higher yield • loss of habitat • migration or change in distribution • extinction
Which metabolic process produces water
Respiration of glucose
Why was more water lost by breathing during a runnng race
more energy needed
(so) more (aerobic) respiration
(so) increased breathing (rate / depth) (to supply oxygen or remove carbon dioxide / wate
Why the students place the quadrats at random positions
there is an uneven distribution of dandelions or (more) representative / valid or avoid bias or more accurate / precise mean
Other than light what are the other environental factors that affect the growth of dandelion plants
temperature • water • (soil) pH • minerals / ions • wind • herbivores
Advabntages of asexual reproduction for bluebells other than only one parent is needed
many offspring produced
• takes less time
• (more) energy efficient
• genetically identical
offspring
• successful traits propagated
/ maintained / passed on (due to offspring being genetically identical)
• no transfer of gametes or seed dispersal
• not wasteful of flowers / pollen / seeds
• colonisation of local area
Why is sexual reproduction is an advantage for bluebells
genetic variation (in offspring) (so) better adapted survive
(and) colonise new areas by seed dispersal
or
can escape adverse event in original area (by living in new area)
many offspring so higher probability some will survive
Use of ethene
To reduce the time taken for tomatoes to ripen
Uses of auxin
To stimulate root growth in plant cuttings
Uses of gibberellin
To promote seed germination
Give one wat that biomass is lost between trophic levels
inedible parts / example or egested / faeces or respiration / as CO2
A large amount of untreated sewage entered the river. Many fish died. Untreated sewage contains organic matter and bacteria
bacteria decay organic matter / sewage / algae / dead plants
(by) digestion
(and) bacteria respire aerobically
or
respire using oxygen
(which) lowers oxygen concentration (in water) or
fish have less oxygen
(so) reduced energy supply causes death of fish
The percentage of fat in milk is controlled by one dominant allele and one recesive allele
How many diff phenotypes would this produce
2
How a change in one amino acid in an enzyme molecule could stop the enzyme working
different protein made
active site changed
so substrate does not fit / bind
How to prove an animal is heterozygous usinga family tree
produces (some) offspring with high-fat milk
or
not all offspring have low-fat milk
The scientists want to producea type of cattle that makes large volumes of low-fat milk. The scientists will selectively breed some of the animals. Describe how the scientists would do this
find female with low(est) fat in milk and high(est) milk yield
find male whose female offspring have high(est) milk yield and low(est) fat in milk
or
find female with lowest fat in milk
or cow 13 (1)
find male whose female offspring have high(est) milk yield (1
or
cross the best (for both features) female with the best male
select best offspring (for both features) from each generation and repeat for several generations
Order of classification
Kingdom Phylum Class Order Family Genus Species
Binomial name order
Genus species
How ancestors of modern lemurs reaches madagascar - currents towards
carried by (favourable) currents on masses of vegetation
Describe how the ancests of modern lemurs may have evolved into the species
isolation of different populations
habitat variation between lemur populations
genetic variation or mutation (in each population)
better adapted survive (reproduce) and pass on (favourable) allele(s) to offspring
(eventually) cannot produce fertile offsprin
Name two types of mo that cause decay
Bacteria
Fungi
How ph can be measured
Universal indicator (paper/solution) Ph meter
Control variables for milk deay
volume of milk • exposure to air / oxygen • sterilise test tubes • treatment of milk before investigation • freshness / age of milk (at start) • time of day pH was measured
The tim taken for cows milk to reach ph 5 at 10C is less than the time taken cows milk to reach ph5 at 5C
bacteria / microbes /
microorganisms / fungi dividing faster (when warmer)
• reactions (in the bacteria) are happening faster (to decay milk)
• (because there is) more (kinetic) energy
• enzyme activity is higher (at 10 °C than at 5 °C)
Suggest reasons why the diff types of milk took diff lengths of time to reach ph5
different concentration / type of fat / lipid • different concentration / type of proteins / carbohydrate / sugar • different (amount / type of) bacteria present • may have been pasteurised by a different process • different starting pH
The increasing human population has caused a decline in fish stoks. Descibe how fishing quotas can help to return fish stocks to sustainable level
fewer fish caught or limit the number of fish caught
(remaining fish) can reproduce
Suggest one reason why some poeple are concerned about the use of goolden rice
gene may contaminate / enter other breeds / species
• reduction / extinction of population of wild / traditional rice
• reduction / extinction of population of flowers / insects
• high cost of seeds
• may have too much vitamin A
(in diet)
Explain phototropism (fom given diagram
side nearest the lamp) receives more light (on side P)
(therefore) unequal distribution of auxin
(auxin causes) more growth on side away from the lamp
Why is DNA described as a polymer
many (joined) nucleotides or monomers
Describe the structure of a nucleotide
phosphate
(phosphate attached to a) sugar
(which has 1 of 4) base(s) (attached to sugar)
(bases) are A, C, G and T
Some parts of DNA do not code for proteins. Describe how non oding parts of DNA can affect the expression of genes
(non-coding parts) can switch genes on / off
Descirbe one similarity between the processes of mitosis and meiosis
DNA doubles / copies /
replicates (once)
• increase in the number of mitochondria / ribosomes / sub-cellular structures
EGive reasons hwy the fossil record is not clear for older species
fossils buried deep(er) so
hard(er) to find
• fossils smaller so harder to find
• more likely to be destroyed by geological activity / earthquakes / erosion
• oldest organisms were soft- bodied so most of the tissue decayed
• dating older fossils is hard
• older eras less researched by
scientists because less to find
• (usually) unclear when one species evolves into another species (because not enough fossils found)
The different therory said that changes in an organism during its life could be inherited. Who proposed this
Lamarck
Explain how a fossil may have been formed
snake is) covered in sediment / mud or sinks into the mud (then) the soft parts decay / are eaten or bones / hard parts do not decay (so) minerals enter bones Or bones are replaced by minerals
Give reasons why a species might become extinct
changes to the environment • new predators
• new diseases
• new (more successful)
competitors
• catastrophic event /
described event
1
AO1/1 4.6.3.6An airtight compost heap causes anaerobic decay. Explain why the gardener might be against producing compostusing this method
Methane is produced
Which is a greenhous gas/causes global warming
Explain how the carbon (from dead leaves which drop onto floor) is recycled into the growth of new leaves
statements:
• (carbon compounds in) dead leaves are broken down by microorganisms / decomposers / bacteria / fungi
• photosynthesis uses carbon dioxide
explanations:
• (microorganisms) respire
• (and) release the carbon from the leaves as carbon dioxide • plants take in the carbon dioxide released to use in photosynthesis to produce glucose
Use of carbon in growth:
-gucose produced in photosynthesis is used to make amino acids/protein/cellulose
-required for the growth of new leaves
Give reasosns why oe strawberry may decay quicker than another
(Storage conditions)
- at higher temp/hotter
- more oxygen
- more water/moisture
- contain more mo that cause decay
Suggest reasons why people might selectively breed cats other tahn preventing cauisng allergies
so that they do not have
specific genetic defects
-to produce docile cats or so they are not aggressive
-for aestheic reasosn
Describe problems inbreeding causes
- more likely to pass on recessive/genetic disorder
- more likely to be susceptible to diseaases
Explain how the cat has been produced usin selective breeding
parents with the desired characteristic are selected
• the parents are bred together to produce offspring
• offspring with the desired characteristics are selected and bred • this is repeated over many generations.
Parents who produce the less fel d1 are initially selected
- in their offspring there will be individuals with differing amounts of fel d1 is produced
- of these, in each generation, the lowest fel d1 producing individuals are chosen
- care is taken to ensure cats are healthy and avoid possible problems associated with selectiv breeding
- over time the population of selectively bred cats will produce less fel d1
Suggest two other possible disadvantages of intensiv farming methods
-diseases spread more rapidly
-antibiotics can build up in the food chain
Or
Overuse of antibiotics
-increased use of fossil fuels to heat the barn
‘Food security is a serious problem in remote communities in canada. This is becaue aboriginal communities are eating fewer traditional foods’ one being seals.
Why might the conclusion in the newspaper not be correct
Aborigional people can eat other foods(so might not be infood insecurity)
We do not know if other (traditional) food sources have declined
A urine testcan be used to check for the presence of glucose in the urine. Suggest why a blood est is more reliable than a urine test for diagnosing diabetes
Could be other reasons for glucose in urine
Or
Blood test gves current/immediate result, urine leveles may b sevral hours old
Or
Not always glucose in urine
Suggest why patients are not allwed to eat for 8 hours before the glucose tolerance test
Results not affected by glucose from food
Or
8h is sufficient tiem for insulin to have acted on any glucose from food eaten
Or
So that there is a low starting point to show the effect
Hyperthyroidism is caused by an overactive thyroid gland. Suggest what would happen in the body of a person with hyperthyroidism
-too much thyroxine is released into the blood
-which raises BMR
-causing increase in formation of glycogen/lipids/proteins
Or
Increased rate of respiration
Or
Increase in breakdown of excess proteins
What should the pentagonal stucture on dna molecule be called
Sugar
A gene is a length of DNA
What type of substance does a gene code for
Protein
How could the student keep the milk at a constant temp for 5 days
(Put beaker in a ) water bath
Give the reason why the peson should not move during teh investigation (where body temp is measured)
movement would release (extra) heat • movement would increase body temperature • movement would increase sweating
The results show that when the icecold water was drunk, the temp near the brain decreased. Explain why the temp near the brain decreased
blood is cooled at stomach / mouth
(cooled) blood flows to the brain
The thermosregulaty centre in the brain responds to the decease in temp. How does the thermoregulatory centre send info to sweat glands in the skin
via nerve(s) / neurones
or
via (nerve) impulse(s)
Describe how mo in the layers of the soil help to recyclce chemicals in the dead plants in a compost heap
digestion or large molecules to small molecules
• enzymes or named example
• respiration
• production of carbon dioxide
• release of mineral ions or named example such as nitrate / phosphate / magnesium
Describe how the chemicals from decayed dead plants are used again by living plants
- carbon dioxide (from air) taken in by leaves
- by diffusion
- via stomata
- carbon dioxide used in photosynthesis
- making glucose / sugar / starch / cellulose or making other correctly named example
- (named) ions taken in by roots
- by active transport
- nitrate ions for making amino acids / proteins / DNA / chlorophyll
- phosphate for making DNA
How should the student decide where to place the quadrat? Give the reason for your answer
Random coordinates
(Grid and) coordinates
To achieve randomness
Using the mean from this investigation to calculate the number of daisy plants on the lawn may not be accurate. Give two reasons why
too few quadrats
or quadrat too small
sample may not be representative of the lawn
Give ways coordination by the endocrine system is different from coordination bby the nervous system
coordination by endocrine system is:
slower
longer-lasting
(chemical / hormone) via blood instead of electrical / impulse / neurones
Describe hoow the algea gets energy
from light / sunlight
absorbed by chlorophyll / chloroplasts
Give the reason why a mutation in the gene coding for heamoglobin could be harmful
mutation means less oxygen for (aerobic) respiration
Give evidence form positive correlation graph that beak depth is an inherited characteristic
offspring have similar beak depths to parents
Scientists suggest that mpre than one gene controls beak depth. Suggest why
parents of a given beak depth produce offspring with several beak depths
Evolution explanation
- natural selection takes place
- when an animal randomly mutates it may be better suited to it’s environment eg.
- this animal is able to (get more food) and reproduce passing on this allele/characteristic to it’s offspring
- those who have not adapted will not be able to (get food) and therefore will not be able to reproduce
Selective breeding explanation
- male and female with desirable characteristics to most extent are bred together
- the offspring with the most desirable characteristics are bred together
- this continues eliminating offsirping/organisms that do not have the desirable characeristics
Decay practical- what to have n conical flask
5 drop cresol red— indicator
5cm milk
7cm sodium carbonate
Once warmed add 1cm lipase solution
Indicator at start-decay of mlk
Purple
Cresol red when acidic
Yellow
Things to consider
- use clean test tube for milk solition each time
- ANY TRACES OF LIPASE FROM previous experiment will start early
- diff to judge exact colour change
- reduce effect, share sata w/ other groups and find mean
How is urea produced
- amino acids deanimated to form ammonia
- ammonia converted to urea
Commercial uses of gibberellins
- ending seed dormency
- promoting/starting flowering
- increasing size of fruit
Describe structure of dna
-polymer
-made up of two strands forming a double helix
-four diff nucleotides
=consist of common sugar and phosphate group with a base attatched to the sugar
-bases are A,C,G,T
Describe protein synthesis
- mrna leaves nucleaus and binds to ribosome
- carrier molecule brings a specific amino acid
- amino acid added to growing protein chain
- protein chain folds up hwen it is complete in cytoplasm
Why monkeys caused extinction of lemurs
- monkeys passd on disease form lemurs
- monkeys killed the lemurs
- monkeys more successful in competing for resources/habitat
Extinction
-no remaining individualls of a species left
