What property of water helps living organisms maintain their internal body tee s9ek2 ;y1f99 sbwaj6jvbl1wmperatureeb sw9 1k 9 jaw1692lbys;efjv?

  Which of the following isol 8hnvg/a;,.k o (zsm not soluble in water?

  What substances are attracted to water and form intermoleyj,5disem -x lhn)c+eb2/s(3 aw4v ui cular bonds with water moleculesbw2 md,h+u ic-lxv)siys 43 n5(j/eea?

  Which of the following is a reason foqxwif l,c1f/ f.20 zigr the retention of water on Earth?

  What is the most accepted theory for the origin of water on Earth?hcxonb 5i:ux )v0cx:2

  What intermolecular bond is responsible for water's uym 7v6unx.4kcohesive, adhesive and thermal propertu67u mx.y vkn4ies?

1.Outline how hydrogen bonds form between water molecua:: b-km iem7sjxk3 +tles.

2.State one of the ways how hydrophilic substances interact with water.

3.State one of the ways how non-polar molecules interact with water.

4.Distinguish cohesion and adhesion.

  Which property of water ew5/h,p+n yk4lk0e zxb nables marine animals such as the ringed seal (Pusa hispida) to stay afloat in water without expending largeyx 4 kl+p,e/wbznh05k amounts of energy?

  The cohesive and adhesive properties of water allow xylem /2e )fzb mnuvsy-xn42 vessels to transport wat4z-)2e smvnunbf/ y x2er inside plants.

Which of the following are correct descriptions of how these properties are related to water transport in plants?

  Which of the following is a reason that the Earth is considered to be in ‘The ih 1 g.tzz(q-r pzt/i/+q md8 xg,e*ljGoldi re1zqj8+ .plti/,xqd g( g*iz zmt/h-locks zone’, but Saturn is not?

  Which of the following statements about the dipolar,ani-8sij h1 hity of the water molecule are tr1i h-n si,hja8ue?
I. Oxygen attracts the shared electrons stronger than hydrogen.
II.Hydrogen atoms are partially negative.
III.The shared electrons spend more time closer to oxygen.

  Which of the following is not a reason that scientists look for the pr7t u jfu:)7pd) dl( nastr:y(iesence of water on planets as a sign of ext)i : d) uju7lpf((yn:as7dt rtraterrestrial life?

  Which term to describe a property of water is matched to its correct defininc4:hklj j5 ;xtion?4njhxc j ;k5l:

  The image shows a wal29i9in 4debghv g t9,ter strider (G. lacustris) on the surface of a pond. What propertit4g 9egl 92bvd,ni 9hy of water is not depicted in the image?

Below is a picture of a wld9cyo:;5p bc ater strider (Gerris sp.).


1.Explain why the water strider (Gerris sp.) does not sink.
2.Describe, using an example, the importance of water as a solvent in living organisms.

The image shows a ringed seal (Pusa hispidlb1ea2 znkc a+og 7)+ba) that lives in the Arctic Sea.


1.Distinguish between the physical properties of air and water that allow the seal to mostly live in the sea.
2.Ringed seals glide into the water head first from ice shelves, rather like humans diving into a pool head first. Explain the advantage of entering the water in this way rather than ‘belly-flopping’ into the water.

  An investigation was carried out intoyjxwo( ;iw10 mgb*;jx q8vo3j the effects of household detergents on aquatic habitats. Scientists tested the effect of different household detergents on the surface tension of water in order to better understand the impact they may have on organisms living on the y8o(1 v;x qj wx ojj3;mbw*ig0surface.

A paper clip was folded slightly on one side and rested on the surface of the water, maintained at a constant temperature and contained within a water tank. Drops of detergent solution were slowly added to the water tank until the paperclip sank to the bottom. The volume of detergent solution taken to sink the paperclip was recorded.

Detergent solutions were made by adding 5 ml of detergent to 15 ml of water.


1.Describe the relationship between the volume of detergent solution added and the surface tension of water.

2.1.For the Easy Clean detergent, calculate the mean number of drops of detergent needed to sink the paper clip.
Mean =  ml
2.2.Estimate how many drops of Easy Clean detergent solution it would take to sink 5 paper clips.

3.1.State one variable, other than those given, which would need to be controlled in this experiment in order to achieve a valid result.
3.2.Suggest one method that could be used to keep the water at a constant temperature.
3.3.Explain the importance of maintaining water at a constant temperature.
3.4.Identify one potential source of error in the methodology.
4.Suggest why different numbers of drops of detergent solution were needed to sink the paperclip between each type of detergent.

  Which of the following is not a real-life example of 4 eahlknn-uba 2wv sn ab1+0*9adhesion?

The image shows a cross-section of the vascular tissu)g-hel fs;9jh fqlim f h,8- 9f6hq.eke of a woody dicot stem, showing the annual rings of hf9; ql.sih) 8e,--jk q f6hl9fmegfhphloem and xylem.


Explain how the properties of water allow it to be transported in the xylem.
Describe a physical property of water, other than those that are important for the movement of water through the plant, that makes water essential for the survival of plants.
Outline why plants cannot use water to transport lipids.
If the temperature drops to -1$^{\circ}$ for a few hours suggest a reason why the water in xylem may not freeze.

  The black-throated loon 9h 08at(p-d fliqad)v)en n .6xknvv5 (Gavia arctica) is a bird that lives near large bodies of water in cold climates. Which of the following is a correct description of how the propertiee.05 vi a9 vxt)khpnl)a(fqv6 ndd -8ns of water may make winter temperatures more moderate for the black-throated loon?

  Which of the following4q*n pbax:2r(ckdaszq( d;.k statement(s) about the role of water as a solvent is corrbds(:* r d;qk .anak2pqz x4(cect?

I. Salt can dissolve in water because it is hydrophilic
II. Lipids cannot dissolve in water because they are non-polar
III. Cellulose can dissolve in water, as it is able to form hydrogen bonds

  The micrograph below snbvh *9+onx* qf7jx;shows the longitudinal cross-section of a stem from a plant in the Pinus genus. Xylem vessels are clearly vissqnv o* nx7xj*f; +9bhible.


The xylem is composed of hollow, tube-like tissues that transport water through capillary action. What property of water explains capillary action?

The diagram shows a solar system very similar6)l 2 ezr/u2exrd gd)t to ours, where five planets orbit )6 ux)d2/der2zlet rga central star.


1.Define the term “Goldilocks zone”.

2.1.Label with the letter R the planet that is least likely to have extraterrestrial life present.

2.2Explain reasons for your answer to part (i).

3.1.Some of the planets in this solar system have water present on them. Suggest where this water might have come from.

3.2.Explain why the planets referred to in part (i) have retained water, whereas others in this solar system have not.

4.Suggest one other biological molecule, other than water, that may be a sign of life on a planet.

  Which of the following statemenkdokx-7 5gu9lte -a0a)w,vke ts explains how water has facilitated the evolutiox-kaea- d7u,kowt 90 elg )5kvn of life on Earth?