B1-B3 June 2015 foundation

Write down two other features of reflex actions (2)
fast (1)
 automatic (1)
People who smoke are more likely to get infections in their lungs. Explain why (2)
mucus not wafted out / removed (to be swallowed) (1)
mucus builds up (1)
holds microbes in respiratory system / microbes not killed (by stomach acid) / microbes not removed (1)
Explain why blood in the arties is under pressure (2)
due to contraction of heart (muscle) (1)
 so that blood reaches all parts of the body (1

What conclusions can you now make about how strong the link is between the breedinmg os snowy owls and the number of lemmings? (2)
reasonably strong because (no mark): the peaks of the lemmings always coincides with presence of snowy owls nest / ORA (1)  but many snowy owls nests / breeding in 2004 and 2007 when there are only small peaks in lemming numbers (1)
 Which fly A, B or C is most likely to be Drosophilia melanogaster? (2)
fly A (1) because it has many features that are similar / dark bottom of abdomen
Natural selections is now widely accpeted as a theory of evolution. Explain why (2)
idea that there is more evidence now, because it has been tested by (a wide range of) scientists
Which pod was most at risk? Explain your answer (1)
• pod A falls from 29 to 23 after the spillage • pod A falls from 36 to 23 overall • pod B falls from 22 to 13 (1990) / 12 (1991) / 11 (1992) • pod A falls by 6 after the spillage • pod B falls by 9 / 10 / 11 • pod A starts to increase in 1991
 Indicative qualitative comparisons may include: • pod A begins to fall before pod B • pod A falls more than pod B overall • pod A falls less than pod B after the spillage • pod B falls more rapidly • pod A starts to increase but B does not
 Indicative qualitative descriptions may include: • oil kills whales • both populations fall after the oil spill

Liz wants to breed plants that have larger fruit. Describe how she can do this by selective breeding (3)
select / choose plants that produce bigger fruit (than the others), breed these together, repeat selection and breeding over many generations
Liz eventually breeds a strawberry plant that has larger fruit. She then decides to let his plant reproduce asexullay. Explain why liz wants the plants to reproduce asexullay instad of planting seeds (2)
(new plants) will be clones / genetically identical (1)
so will (all) have large fruit (1)
What are stem cells? (2)
undifferentiated cells / unspecialised cells (1)
 idea that can develop/change into different types of cells (1)
How were these stem cells different from normal mouse stem cells? (2)
made from skin cells (1)
 normal stem cells come from embryos (1)
What organ makes the rate of blood flow change and how does it do this? (2)
heart (1)
 because pumps harder / faster