What property of water helps living organisms maintain their internh9ou*3)ay 8sufl+c) gb 1vzyral body temperatu yura8sb3fo9uy+g)cvh1 z *)lre?

  Which of the following is not solublgi *i.ukn+z0je in water?

  What substances are attracted to water and form intermolecs*wg g j*8g4miular bonds with water mol*ggjmw * 8s4giecules?

  Which of the following is a reason for tke 6xqvv0 6mh-aqv28ahe retention of water on Earth?

  What is the most accepted theory for the 0qm1c s;fx; 1mfhd(b dorigin of water on Earth?

  What intermolecular bond is responsible for water's cohesive, adheovfb . ovis*j a s70k(3s;/,hvc *ffmcsive and thermal proper*f,h(v j sfcv.vf;ob/o ss0i3ma7*kcties?

1.Outline how hydrogen bonds form.p1x 9wcqm5r 4pxyywx o flr): c);r;r 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 enables marine animals s z1z (o,ppknr6uch as the ringed seal (Pusa hispida) to stay p6ko(z z1p,rn afloat in water without expending large amounts of energy?

  The cohesive and adhesive properties of water allow xylem vessels to transport 75.esetro e-i iau+/y q *utz,xw5r s*water inside u.*u qy wx5-sze/iie ttoe*rs 5+ar7,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 d4cd:aog5 f1vn n/7zlis considered to be in ‘The Goldilocks zone’,7d4czn5 :nao l vdg1/f but Saturn is not?

  Which of the following st qlvd rpwzelwf j)-9*q4v3p*/atements about the dipolarity of the water molecule are t*rf4ple z/vpq * vqw-ldjw)93 rue?
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 sci*j6ev/0 p rmdcentists look for the presence of water on planets as a sigm*e 6 0rc/jpvdn of extraterrestrial life?

  Which term to describe a property of y9e .yd8)lc(,u)cfu)xb bo7-gvzisxwater is matched to its correct definition?g uy,xf )ivd7uz .8lo9e-b y)cbc )sx(

  The image shows a water strs(,k8 l t.ensxider (G. lacustris) on the surface of a pond. What property of was8tex nl sk(,.ter is not depicted in the image?

Below is a picture of a water strider (G6utaer vk/bi;lg 8o5zjd(h 1/ 8 cr.gzerris 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 ring+dx on hjxort-i a/:l.: g+p0ged seal (Pusa hispida) 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 into the effects of household detergent5ne*ydiiay; wo;o9ixn/f;f6s on aquatic habitats. Scientists tested the effect of different household detergents on the surn95oi;w;o ;f da*eif x6y/nyiface 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 examd99dv b ,lkm+4p9-+zh p(wj /dytqin gple of adhesion?

The image shows a cross-section di,jpym2mo/1zt 0k e:)ro l7t a2q5xvof the vascular tissue of a woody dicot stem, showing the annual rings of phloem a)r72kp:voxz,ota mq 50imld1 eyt 2 j/nd 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 (Gavia arctica) f/+vzwb g: k1- io)2ziik0meq is a bird that lives near large bodies of water in cold clb-g z:kkei o+ii fv1m)2/q0 wzimates. Which of the following is a correct description of how the properties of water may make winter temperatures more moderate for the black-throated loon?

  Which of the following statement(s) abo (ot /)nzbbv4mut the role of water as a solvent is corr)b/ mvt ob(n4zect?

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-sec)o-c t8mtg ,mttion of a stem from a plant in the Pinus genus. Xylem vessels are clearly co,t -tt)gmm8visible.


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 similar to ours, where five planets oru4+ zgace+bo*4kn, fu bit a cfbgen*4zu ,+c4a + okuentral 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 statements explains how water has8 r79g. qkm81st.zvk y4rvhip *, tolm facilitated the evolutionpt7*l 8sr,to gq.4k8v1vk. mihm9zry of life on Earth?