What property of water helps living organisms maintain their internal body teucibkvw8;h eu(4:g1x4 t -nbhmperau g (b4: iet u-14khxwvhnbc8;ture?

  Which of the followi)byuy tdl5b;fux; l/36dj4 rang is not soluble in water?

  What substances are attracted to water and form intermolecularxhn0 to6 9wsa6y3 naugql(pl-+;7 rod bonds with water mol n lywdt lrn36au a7x0g(p+6o-h ;soq9ecules?

  Which of the followi;h5tijjl(ho 9ath4d2 ng is a reason for the retention of water on Earth?

  What is the most accepted theory for the origi l+ jx8irshk;o2b)ebp0. x9spn of water on Earth?

  What intermolecular bond is responsible for water's cohesive, adhesive and th;s -kh 3:qxmqfjkx-* *secwb 0ermal *k x-;be*3kjhfcsqw0xmsq: - properties?

1.Outline how hydrogen bonds form between watn2. rsctgsn8dh -c5z5r 4 (ufme6fsx;er 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 such as thex8w1y+ca gztg:*p t qk+d8j0rrqt 9/g ringed seal (Pusa hispida) to statpy rdac+q*zwrqg +g0 1/j t9g88:xk ty afloat in water without expending large amounts of energy?

  The cohesive and adhesive p+v5sp uw3x/r eroperties of water allow xylem vessels to transport wat5x+v3 uwps re/er inside plants.

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

  Which of the following qr;/ zdf,o w ,7rf70qa q2e2byq q6qsjis a reason that the Earth is considered to be in ‘The Goldilockb qq 2 qw;fr7/s7z,yqjq6d0fqe,o2r a s zone’, but Saturn is not?

  Which of the following statements about the dipolarity of the water molecu4/fa x) joys4qle are 4s jo)4/yf xqatrue?
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 reaso d1, ;uqj2bv*,tfclxm8 bs6fk n that scientists look for the presence of water on planetsv ;blqu f6,sxmkbdf,jc*21 8t as a sign of extraterrestrial life?

  Which term to describe a property of water is matched to its correct dhkb+oenn(c2hgic (/ 4krd07c efinition?e /cgdc7n(o04+kikb( 2 hnrch

  The image shows a water striderq//j8fn *a+ngmad, ta (G. lacustris) on the surface of a pond. What proq*a // jfmtaa 8,dgnn+perty of water is not depicted in the image?

Below is a picture of a wahfwevvnb(w96. a - 7uvter 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 hispida) that lives in the1xa.i-(ldft s 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 carriee pcl-qkv )no0,; 0ygvd out into 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 lik0vl -poqv )c0,;gnyeving 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 exa6.p4jeo sqyuh8l6c c 3mple of adhesion?

The image shows a cross-section of the vascular tissue of a woosgw(;m f9r 0s r:emy j.sx;9kcdy dicot stem, showing the 9 9kmw(r;:xs; jsmfc.syg er0 annual rings of phloem 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 (Gavia arctica) is a bird that livev*5,zpkkl r3ks 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 temperatures *r vkz,lk3p5k more moderate for the black-throated loon?

  Which of the following statement(s) about the role of wate4y--w7c uy4mpdt;pmf r as a solvent is correctup yd cf-w4;7 ptmm-y4?

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-secti4n7toqx ui 2.x4k6)xy -ciu epon of a stem from a plant in the Pinus genus. Xylem vessels are x xn44k) o-u26ui7 icqp xeyt.clearly visible.


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 plan okc(:7ang)ests lbmbtg+ z-r a2p5hl)i .n44 ets orbit a central star.goh)n izcb(bn2)lm :tg+45ak.t4s rlpa- se 7


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 +5ivbm t*mw+x;fy :c8f3tkxkstatements explains how water has facilitated the evolution of li;+mx: kkf85f* v mbitwxcy t3+fe on Earth?