agricultural science

We didn't cover Pigs tbh.. Just sheep, dairy, cattle and cereals

that ****ing fly question... man.. haha Grand tho. fair paper.

Saffy wrote: »

I was relying on Q 4 but I didn't recognise any of the experiments!:eek:
We didn't do any - just read about 20.

parts of Q5

I usually get 100% for Q7(genetics) but I couldn't get the genetic cross and I couldn't remember the fruit fly thing:rolleyes:

Q9 - just bluffed my way through it!!

Q4 : Percentage germination of a cereal was straightforward. Plant 100 seeds in a seed tray, water/light/nutrients etc, leave for a week. Count how many have germinated.


Selective herbicide: There isn't really an experiment for that, a lot of my students made it up, so they tell me, I'd probably say : Two/three areas of land with crops planted. One is a control:no herbicide, apply X amount to second plot. Apply Y amount to third plot. One without has weeds. One with small amount has no weeds but crops grow. One with large amount kills weeds and crops as too much selective herbicide has the effect of a total herbicide.


Bacteria in clover is the same as bacteria in anything else. Crush root nodules, spread on agar on petri dish, incubate, observe bacterial colonies.


Q7: genetic cross, something similar came up a few years ago but it was the incomplete dominance cross they used. You were supposed to figure out the ratio from the numbers given, 42:13 is roughly a 3:1 ratio. It also mentions starting with homozygous parents and suitable crosses so you had to do at least two.

Cross 1: GG x gg
Gametes: G g

Genotype: Gg
Phenotype: Green

Cross 2: Cross F1 genotype with itself

Gg x Gg

Gametes G, g and G, g

Genotypes GG, Gg, Gg, gg

Phenotype:
3 Green, 1 albino

Saffy wrote: »

yay!!! I got that - I thougt it was wrong though:o

Happy days!

not bakunin wrote: »

nice exam overall.........wrote 2 pages on the ewe and lamb mortality bit...

what was the digestibility of grass over the growing season bit? i bluffed a bit, said that it had to do with carbohydrate levels, and cellulose in the cell walls. is that ok?

yeah, i got that genetics bit too! yaaaaaaaay


(but whats a lethal gene?)

A lethal gene is a gene that can be mutated gene, and causes death (possibly premature) in an organism if it is the dominant gene (it would normally be the recessive one).... I didn't think it was a fair thing to ask to be honest. I can't think of one off the top of my head, but haemophilia in males is a recessive trait. It is thought that a female embryo carrying two haemophilia genes is often miscarried, hence the lack of female haemophiliacs. Don't quote me on that, but that's the best example I can come up with.


Digestibility of grass: High carb levels early on in the growing season (may), therefore high digestibility, after the seed head has flowered (june), carbs convert to fibre to support seed head, so digestibility drops as fibre levels increase and carb levels decrease. if you use the green ag book (breen and mullen) the graph is in ch 19 on grassland in the section, productivity, palatability, digestibility.

rainbowtrout wrote: »

A suckler cow will need to be fed extra ration during pregnancy (production) for her unborn calf and after pregnancy to produce milk for the calf as it suckles her, after the calf is eventually weaned she will be back on maintenance ration.

is it true that some farmers decrease the feed to cows in the later stages of pregnancy to have them 'fitter' for birth - leading to easier calving?

Seinas wrote: »

Just looked at the exampaper there, its a shame that nothing at all came up on pigs.. A vital sector to the economy and then info in the ag.science book is completely outdated:mad:

Syllabus hasn't changed since 1969 and from what I understand publishers aren't all that interested in producing an ag science book because it's a minority subject. i.e. no profit. So the main book that is used is 20 years old.

Pigs was on ordinary level though.