1. Ferns and mushrooms both grow and reproduce themselves.

(a) In what way are they similar in their reproduction?

(b) Are they similar in the way they get food? Give a reason.

 

 

2. Method of breathing.

Group A: Crab, damselfly nymph
Group B: seal, walrus
group C: tubifex worm, tadpole
group D: water stick insect, mosquito larva.

(a)One animal in the diagram has been classified wrongly. Name the animal.

(b) In which group (A, B, C, D) should this animal be classified. Why?

(c) The water beetle cannot be placed in any of the groups above. Explain why.

 

3. In germination, the part that grows out from the seed first is the ________________, followed by the ____________________.

 

4. When a new plant grow from the bud of an old plant (eg. ginger), this is an example of _______________?
(a) fertilisation
(b) dispersal
(c) reproduction
(d) adaptation

 

5. Why is is that plant do not grow as well in boiled water which has been cooled to room temperature than in normal water which has not been boiled?

6. A lorry transports ice blocks from a factory to a market. The ice cubes are covered with thick cloth.

What is the main reason for covering the ice blocks with thick cloth? Explain

No one is replying because these can definitely be found in your textbook.

Cheers!

1) a) they reproduce by spores

1 b) Not similar. Ferns photosynthesize, mushrooms do not

2) not sure, no diagram seen

 

3) first is root, second is stem (I think)

4) reproduction

5) no idea...

6) Slow down the melting of ice.

I'll take the chemistry question :

 

>>> 5. Why is is that plant do not grow as well in boiled water which has been cooled to room temperature than in normal water which has not been boiled? <<<

 

 

Boiling or high temperatures provides more than sufficient energy to overcome the permanent dipole - permanent dipole bonds between the aqueous oxygen molecules and the polar water molecules. In effect, the higher the temperature, the lower the solubility of gases (notice that this is in contrast to the higher the temperature, the higher the solubility of solids; the reason being for ionic solids, enthalpy of solution requires endothermic enthalpy of lattice dissociation first (by Hess Law), before the exothermic solvation enthalpy applies; for covalent solids, higher temperature is required to increase the rate of positive entropy effect as well as to overcome any induced dipole-dipole van der Waals forces between the covalent solid partices, so that they may thereafter form solvation bonds with surrounding polar water molecules instead). The end result is that any dissolved oxygen is released from the boiled-and-cooled water; as compared to 'normal water' that will contained some dissolved oxygen.

 

While this variation on boiled-water vs normal-water does not affect terrestrial plants much (they obtain their oxygen by diffusion, primarily through photosynthesis during the day, and in the night through the stomata of leaves into thin film of water on the spongy and palisade mesophyll cells, where they diffuse into and across cells in the aqueous state (ie. permanent dipole - permanent dipole bonded with water molecules); however any minimal effect on terrestrial plants will be from their roots, which need oxygen to carry out aerobic respiration to provide the ATP (Adenosine TriPhosphate) required to carry out active transport of mineral ions against their concentration gradient from soil solution into root hair cell so as to set up the required osmostic gradient to allow osmosis of water into occur from soil solution to root hair cell.), but aquatic plants are more significantly affected, particularly at night, because they too, like fishes, rely on dissolved aqueous oxygen in the ambient waters to provide them with the oxygen they require for aerobic respiration to provide ATP for their metabolic needs.

 

 

 

 We Love Primary 6 Science!

huh?

pri 6 knows oxidative phosphorylation?

 

Originally posted by maurizio13:

huh?

pri 6 knows oxidative phosphorylation?

 

i dun think so leh... too cheeminlogy for PSLE liao...

Originally posted by weewee:

6. A lorry transports ice blocks from a factory to a market. The ice cubes are covered with thick cloth.

What is the main reason for covering the ice blocks with thick cloth? Explain

insulation.

last time when i studied years ago... textbook is using sawdust when shipped via cargo ships...

 

the textbooks used during my time still need to study iron ore, tin, timber, latex (rubber), mining industries... like sand quarries...etc.

okay i need serious help with Q2. There is actually no diagram in that question. Just a table with 4 groups of animals.

Thanks for the answers to the other questions. 

Originally posted by Rednano:

insulation.

last time is i studied time is using sawdust when shipped via cargo ships...

but students will ask how does the thick cloth help to insulate, wont they?

Originally posted by weewee:

5. Why is is that plant do not grow as well in boiled water which has been cooled to room temperature than in normal water which has not been boiled?

If i can speculate, I will say the the boiling destroy some of the free living bacteria in the water? eg. some nitrogen fixing bacteria are useful for plant growth. I am prob wrong hehe...

Originally posted by weewee:

but students will ask how does the thick cloth help to insulate, wont they?

minimise the melting by blocking contact with the surrounding air, and the thick cloth maintain the temperature of the ice by shielding it from the heat of the surrounding air.

something to do with:
solid - liquid - gaseous (ice - water - water vapour)

2a) Tapole (breathe with lungs?) should be group with Group A (part b answer)
c) water beetle traps air bubble using its hair.

*I MIGHT be wrong*

Just google it, Google is your best friend! ;)

Originally posted by weewee:

okay i need serious help with Q2. There is actually no diagram in that question. Just a table with 4 groups of animals.

Thanks for the answers to the other questions. 

2a. Tadpole

b. should be move to group a. tadpole uses gills to breath

Group A: Crab, damselfly nymph                              -----> Gills
Group B: seal, walrus                                                ------> Lungs
group C: tubifex worm, tadpole                                -------> Skin
group D: water stick insect, mosquito larva.         ---------> Breathing tube

c. The water beetle traps air in a cavity underneath its wing. and it uses non of the mechanisms listed in the above groups.

Originally posted by Dezhou:

2a) Tapole (breathe with lungs?) should be group with Group A (part b answer)
c) water beetle traps air bubble using its hair.

*I MIGHT be wrong*

Just google it, Google is your best friend! ;)

Haha u beat me to the answers ...

 

i thought tadpoles and frogs are different.

 

Eggs hatch and continue life as tadpoles (occasionally known as polliwogs). At least one species (Nannophrys ceylonensis) has tadpoles that are semi-terrestrial and lives among wet rocks^[15][16], but as a general rule, free living larvae are fully aquatic. They lack lungs, eyelids, front and hind legs, and have a cartilaginous skeleton, a lateral line system, gills for respiration (external gills at first, internal gills later) and tails with folds of skin fins for swimming^[17]. Some species which go through the metapormhosis inside the egg and hatch to small frogs never develop gills, instead there are specialised areas of skin that takes care of the respiration.

 

http://en.wikipedia.org/wiki/Frog

Originally posted by whiskers:

2a. Tadpole

b. should be move to group a. tadpole uses gills to breath

Group A: Crab, damselfly nymph                              -----> Gills
Group B: seal, walrus                                                ------> Lungs
group C: tubifex worm, tadpole                                -------> Skin
group D: water stick insect, mosquito larva.         ---------> Breathing tube

c. The water beetle traps air in a cavity underneath its wing. and it uses non of the mechanisms listed in the above groups.

wow thanks. You are the man!

7. Many animals feed on grasshippers and yet the population of grasshoppers remains big. State two characteristics of grasshoppers that enables them to thrive in a community.

8. Earthworms has special adaptations that help it to survive in its habitat. Write down the adaptation for each of the functions in the table below.

(a) Function: allows it to move easily in the soil
Adaptation:

(b) Function: Allow it to camouflage in its habitat
adaptation:

(c) Function: Allows it to breathe through the skin.
Adaptation:

 

u machiam like we r doing ur homework..

Originally posted by Rednano:

u machiam like we r doing ur homework..

that's what i was thinking also.

can't be everything don't know right, then what's the purpose of going to school?

 

 

Originally posted by maurizio13:

that's what i was thinking also.

can't be everything don't know right, then what's the purpose of going to school?

 

 

to keep them clones off sgf..

Originally posted by maurizio13:

that's what i was thinking also.

can't be everything don't know right, then what's the purpose of going to school?

 

 

if open-ended questions, we can help help a bit...

but now MCQ only... give u choices to choose... oso cant answer...

and i wonder what's the use of www.google.com.sg is for...

Not everything dunno...I have browsed through over 100 questions and these are the few questions i dunno how to do. As for q6, q7 and q8, i roughly know the answer but looking for better inputs.

(3) root followed by ‘shoot’ tends to be more acceptable than ‘stem’

(5) the ‘chemistrical’ answer to this question is too ‘chimp’ to a Primary Level student. Poor boy, hope you did not get confused and lost insterest in Science.
I think the acceptable answer is quite the same as using boiled water to rear fish,... to put it simply,... ..’boiled water contains no oxygen and other elements which the plants need to grow well’. Just like we eat food whithout the vitamins. We may still live, but not healthy.

Hope this shed more light to your doubts.