What property of water helps living organisms maintain their i: ounqw 0 uxy5ma tt4n.4rn5;znternal body temper :qu;0twury4. to na55mn n4xzature?

  Which of the following is not si56tzra:5izkcc 5;fcn uc+ l2 oluble in water?

  What substances are attracted to wa g)yqo pyq+ m/t21h;voter and form intermolecular bonds with water molecu)p1o;q qv/ y+oh2gym tles?

  Which of the followilf555u qona/ ws0,mwd /mh /tnng is a reason for the retention of water on Earth?

  What is the most accepted theory f d/iq*cuhx60 yor the origin of water on Earth?

  What intermolecular bond is r byjwua1y )b1 :5v0xuiesponsible for water's cohesive, adhesive and thermal pr:ab1 yjvyui 1x 5u)0wboperties?

1.Outline how hydrogen bonds fo 1*e.(b(m uf tx81qounbnpv*a rm between water molecules.

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 edmv9 5unugq0r5 8ca3pnables marine animals such as the ringed seal (Pusa hispida) to stay afloat in waav5uq5 80m pr93 gduncter without expending large amounts of energy?

  The cohesive and adhesive properties of water allow xylem vessels to transport w: nqgg8 y(dg6kater inside plants. :q ggg(n8ykd 6

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 di f-qs1hu;5xthat the Earth is considered to be in ‘The Goldilocks zone’, but Sa;q f 1u-xhdsi5turn is not?

  Which of the following statem g.fz0j30gvet 2,10pyqyj g wyents about the dipolarity of the water molecule are true? jy0gwgpf y 0etgq0z.v1 3jy2,
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 scivn0 z2mebk;m1 entists look for the presence of water on n;b10 zmk2em vplanets as a sign of extraterrestrial life?

  Which term to describe a property of water is matc3)a;qk wwulog c/j i( g0oi.7) qaq5zxhed to its correct definition?a.(uo0;z jgq)/qx5w c)ok q73 aglwii

  The image shows a wa b vb.:8uzkt jfj,48zuter strider (G. lacustris) on the surface of a pond. What property of water is .zfujv:4kbj btu,z 88 not depicted in the image?

Below is a picture of a water strider (Gerris8 mq)7 gf1axxv 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 hispida) that lives in the xxa (b *h,cc.t yi2zh9Arctic 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 carrie7yanpe*q ;evm7;zbz, n-+ juhd out into the effects of household detergents on aquatic habitats. Scientists tested the effect of different household detergents on th,ynu;n; z+v7b qz7- epa*hmje e surface tension of water in order to better understand the impact they may have on organisms living on the surface.

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 adhesiontzpw4f o(++ry?

The image shows a cross-section of the vascular tissue of a woody dicot stuuvpy:0ng-of)/ mg z+em, showing the annual rings of phloe zfum+:p g/0v- nuoyg)m 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 (Gaviky c4n9jnmm4ok(;6v 3rqvo;t a 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 properties of water may make winter temperatvqn9 tkr3m(jc;kv;4 n o4oy6mures more moderate for the black-throated loon?

  Which of the following statement(s) about the role of water as a solvends:suq92 tbwfo-1/a93c 9zfof9wqel47k xx ct is corrdeqfl4xo:f/so 9-q93f w2xwuk7c9sza1 ct9b ect?

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 shows the longitudinal cross-*xw; /acfdzc8 section of a stem from a plant in the Pinus genus. Xylem vessels are clearly vidax8/zf*;wc csible.


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 (db2gn.gzj 6yi*+akndv8 /besolar system very similar to ours, where five planets orbit a central sjy*db/8 gd2ke6 nzv.nia+( bgtar.


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 statements explains how t-d;(vyvt ug;water has facilitated the evolution of l;vg-vyu(t ;d tife on Earth?