What property of water helps living organisms mait sgz80fsgae:0uc3wm6a xf*k giz s5 310ytv0ntain their internal body temperatz3yamgzg 0ea1v 6080c:xi fwfst 0ku3 g*sts5ure?

  Which of the following is not soluble in watij(jxn sp x;gsw,;evj)3(q -cp6c ;poer?

  What substances are attracted to water and form intermol-y 928zfo5:vghqi lshecular bonds with water moleculesh2:i8ghl9fs -yq 5 zvo?

  Which of the following is a reason for the retention of water k6ugi bgy f (v4 vy/ifd e4efzp2+x)45on Earth?

  What is the most accepted theory fori tjec r1*.g.d8tbk+w the origin of water on Earth?

  What intermolecular bond is respo8t ojq tn(kr7v/nrt)4s+nk +j nsible for water's cohesive, adhesive and thermal psr7/t +)ntj48ntkvr + knq(j oroperties?

1.Outline how hydrogen bonds form between water miq d55nk( vxn/olecules.

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 the ringed s2h kpvn. eh;2neal (Pusa hispida) to stay afloat in water without expendingp; 2ek2nnh.hv large amounts of energy?

  The cohesive and adhesive properties of water allow xylem vessels to transpo4l5r p8 p7ktajrt water inside 8 akj4ptrpl 75plants.

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

  Which of the following is a reasy4 qub0.c uq fbymq4+;on that the Earth is considered to be in ‘The Goldilocks yu4fmcub+.4 bqq y 0q;zone’, but Saturn is not?

  Which of the following statements about the dipolarity of th, scbm-.3 6ofb-le;htlp9 xuae water molecule are truf9pl; ma.,-b hosc-3t u6 bxele?
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 reasl th,r- 8h;khnon that scientists look for the presence of water on planets as a sign of extraterrestrhnr;8hl k,th-ial life?

  Which term to describe a property of water is matched to its correct definic.yxf1md:/zhf 4xc( :a(soyy tion?:4sdf x(aymcyz(/ xy c:o.1fh

  The image shows a water strider (G. lacustris) on the surface of a pond.vc9 l4 4et5t/l)oo ocz What property of water is not depicted / v44tlcleoc)5o o9 tzin the image?

Below is a picture of a fgath dmj 21tvyxe:z; 0x9+9o water 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 the Arctic Sea. e* u2:i3p styza nd0x( 7ua0qz


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 househ24oza cu d5r h, g7ix1/zasmg9old 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 have4a2 zgcr z,a9 /go 1dhxs5m7iu 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 addef-cnw, p p:;lc(b ;do 4heb+hesion?

The image shows a cross-section of the vascular tix0 js/ m+jh.mo,*a zb/ v6uxnpssue of a woody dicot stem, showing the avnx//u bmp0 os+mh6* jj,xaz.nnual 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 lives near large bodies oyl)3i e;f8tii f water in cold climates. Which of the 3iti)eyli 8;f 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 statemen7wn; m5c/p dyp/lika1 q.if2g t(s) about the role of water as a solvent is correct?p ; 5 idlgyai 27.fnp/kq/1mwc

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-section of a ste0 j3 /v9iwpyg3:od/pain;esc m from a plant in the Pinugp ;ni 0/sw9jcae:o 3 /idy3pvs genus. Xylem vessels are 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 planets orbit b ;r10m z3v wb iom+dbi6k1gs4a cermbi1i mswvz3b kb 1+;g60d4 ontral 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 has facilitated the .3+vry*y y/2rdf+qgrytjg b 2evolution of life2yr+3yj gbf+g v/rr y q*.tyd2 on Earth?