2020 Paper 2 Flashcards
Name 2 types of microorganisms that cause decay
Fungi
Bacteria
Suggests 2 reasons why the different types of milk took different lengths of time to reach ph 5
They had different concentration of lipids
They had different starting pH
Describe how fishing quotas can help to return fish stocks to a sustainable level
Humans catch fewer fish do more of them survive no reproduce
Farming techniques have changed in recent years. Describe: • why more land is being used for farming • how increased farming has decreased biodiversity
the population has increased so there is more demand for food and crops. some crops are also used as biofules as there is more need for transportation. organic farming eg: producing free range eggs requires more farming. fertiliser run off polluting water • use of pesticide damages food chains and more soil erosion. more carbon dioxide (from farm animals / machinery) • more methane (from cows) • climate change or global warming
Suggest why some people are concerned about the use of gm rice
Could create a decrease in biodiversity
Explain what happened to the growth of the seedling on side Q compared with the growth on side P
side q receives less light as it is further from the lamp so more auxin on side q. therefore auxin causes more growth on the side away from the lamp
Why does storing bananas with other fruits cause it to ripen quicker
More ethene produced from banana
Describe how non-coding parts of DNA can affect the expression of genes.
they can switch genes on and off
give three differences between process of mitosis and meiosis
mitosis involves only one cell division whereas there is 2 in meiosis
meiosis produces genetically different offspring whereas mitosis produces genetically identical
mitosis produces diploid cells but meiosis produces haploid cells
In most MRI scanners the person being scanned needs to stay completely still. A functional MRI (fMRI) scanner allows a person to move while the scanner makes images of the person’s brain activity. Suggest how the fMRI scanner could help to find out more about the brain damage a person has
they could take fmri scans when someone is completing a specific activity to see which regions are active and compare to a person without brain damage to see where problem lies
Describe how the brain receives information about light entering the eye
retina converts light into electrical impulses which the optic nerve carries to the brain
The eyes of some birds contain cells that detect ultraviolet (UV) light. UV light is reflected by some fruits and the urine of small mammals. Explain how birds that detect UV light have evolved from birds that could not detect UV light.
a random mutation occurs in retina of some of the birds. a different protein is made in the retina so more variation in the wavelength that birds retina could detect
• birds with the mutation or birds able to detect UV are more likely to see fruits (that reflect UV) • birds with the mutation or birds able to detect UV are more likely to see where small mammals are or have been • therefore get more food (small mammals or fruit) • avoid being eaten (by small mammals) • out competing those birds without the mutation or birds not able to detect UV • so more likely to survive and reproduce or have offspring • by natural selection • passing on allele / gene / mutation to offspring • repeated over many generations
Give 3 reasons why the fossil record is not clear for older species
Fossils are smaller
Fossils are more deeply buried
My be destroyed by earthquakes over time
Give one disadvantage and one advantage of mass extinction events.
advantage: could bring about evolution if species
disadvantage: reduction of alleles
