ag (0315) - Animal: [p] chicken embryos

today..

we cracked open chicken eggs.. WITH CHICKENS INSIDE THEM.

how weird right?

we cracked a bunch of eggs that were weaned purposely for experimental use. they were taken from their mothers/incubators (they're from a hatchery) at differnet time intervals since they were laid. this allowed us to see the different stages of fetal growth.

it was.. interesting.. there's not much ic an say.

the growth was obvious. look at table for deets.

but basically blood vessels developed first, then eyes, then limbs, beak, feathers, etc..

bio (0315) - BoL: [p] nature vs nurture

today.. ok it wans't mentiond, but we talked about a concept in ag:

P = G + E

where:
P = phenotype
G = genotype
E = environment

basically.. we wanted to know the effects of environmental conditions on two organisms with exactly the same genotype, how it would affect the phenotype.

now to have reliable results, we'd need the same genotype in two or more organisms. that's impossible unless we have identical twins etc, or clones. but.. there is a way. we took cuttings from a geranium plant, which means each cutting had exactly the same genetic makeup as the original plant.

now there were a number of environmental factors we considered altering that could affect the phenotype.. including light, soil type, air temperature, etc. but we decided to do water since it's the easiest to control and measure, and is a required ingredient for photosynthesis.

we did about 8-9 cuttings for each variable (water or unwatered) and they were al the same length (9cm) and planted in the same type of soil, in the same sized pots, in the same room. this was to make sure that the only altered variable between the two was the availability of water. none of the cuttings had leaves too, but each had at least one node.

see book for method and details, and results will be recorded later.

phys (0311) - M&G: [p] dc motor

today we had to make our very own makeshift dc motor completely on our own.

i cbf getting into deets of how we failed, but the final result was that we had one working for at least a minute.

we used a copper wire twisted into turns for our coil, suspended by paperclips over a.. neo.. something magnet.

the paper clips and magnet were taped down to the table, and the paper clips were gonnected to the transformer using alligator clips.

so it worked, kudos to the workings of the motor effect.

im falling asleep.. cya guys

bio (0216) - MaB: [p] conserving water

strange prac today using nail polish.

we took a few leaves, and applied nail polish onto small areas on both the upper and lower surfaces of the leaf, then waited for it to dry.

once the nail polish was dry, we removed it using tweasers and looked at it under a microscope.

what we found was the imprint of the leaf on both sides, revealling that the lower surface of the leaf hand much more stomates (hundreds) than the top surface (about ten within that small area)

stomates are found under the leaf because it allows gaseous transfer without excessive loss of water.

bio (1118) - Mab: [p] exhaled air pH cont.

the last bit of this prac done today, using data loggers, pH probes and pH amplifiers.. which looked like transformer cables for the probes.

using a straw i blew into a small beaker filled with 40mL of water for 2min (120sec) and the data logger recorded progress.

it started at around 7.62, and by the end.. right at the end, it hit 4.97.

so that was that

bio (1117) - Mab: [p] exhaled air pH

so.

one of the products of respiration is CO2, which we breathe out when we exhale. now they move around the body through the blood as well, and they are bumped around by hydrogen. so when we exhale, we're actually exhaling hydrogen too. therefore, our breath should be slightly acidic. we tested this today.

first of all, we got limewater, and blew into it using a straw. of course it turned milky, proving that we exhale CO2

the second part, the probe was being dodgy, so we skipped ahead to using universal indicator, which was also dodgy.

first it said our distilled water was acidic, so we had to change bottles.

so anyway.. it started off green (pH 7) and thompson blew into it for 2min. within the first 30 seconds though, it changed colour and came down to pinky-orange (pH 5) and that's where it stayed 'til the end pretty much

phys (1116) Space: [p] filming trajectory

today we did a prac, a familiar prac, about throwing a basketball and filming it. we'll analyze it and further work with it later.. but for now.. we discussed things about it first, then filmed it.

we decided to use the big pipe thing coz it measured up to be 2m long, and it would be totally visible in the video.

the thing was the scale had to be in the same plane as the trajectory (in order to produce accurate results/readings)

oh and apparently the scale might not have been exactly 2m accorind to zhou and monger

wth monger is an english word? haha

and i suggested the camera has to be at the right angle, it cant be looking up or side on of the ball, the lense has to be parallel to the plane of the trajectory (in terms of x and y movement)

catch me?

so we went out, and i filmed udit and tommy throwing the ball back and forth.. hopefully we got some good shots

bio (1112) - MaB: [p] size of blood cells

i missed out on half the lesson coz of prefect meeting.. but i got the general geist.

it goes like this..

at 100x zoom (10 in the lens x 10 in the thingy) we measure (using a transparent ruler) the diameter of the field of view (circle that we see) getting around 1.8 - 2mm, which is converted to 180-200 micrometers

then we zoom into 400x zoom and count the amount of red blood cells seen in an imaginary diameter (around 50) and compare it to the length of the diameter to obtain the size of red blood cells.

white blood cells to measure size, are measured in porportion to the red, (about 1.5 times the red)

their nucleus appeared big and purple

ag (1104) - Lettuce: [p] aphid under microscope

not really much theory behind today's lesson, we just looked at aphids that we picked up on the farm under microscopes.

up close they're actually pretty gross, and green ones look weird.

but we could see them movnig around, but not really sapsucking.. but yeah.

the spider was intersting though haha. eating its own leg? or cleaning it or something..

phys (1030) - Space: [p] pendulum length

the class split into groups to do one length of string for the pendulum each.

our group did 0.8m.

each group measured the period for 4 trials then took an average.

all groups used the same mass ball on the end of the string to not rig up the results.

the experiment was to test whether length had an effect on the period of a pendulum swinging.

my prediction was longer ones would take longer, and thats what the class' results show.

bio (1027) - MaB: [p] enzymes in different pH

today once again we played with milk and rennin.

we used 10mL of milk in 3 tubes, heated to approx 37* - 40*, and then in each, poured 2mL HCl, or 2mL distilled water, or 2mL NaOH

only the acidic one had a result.

milk was spilled on the hot plate today.. it smelt nice for some reason.

bio (1023) - MaB: [p] substrate concentration

in today's prac, we tested the effects of substrate concentration on enzyme reaction rates.

its too bad we didnt finish -.-

basically.. we added 3mL of rennin enzyme to 10mL of solution. the milk concentration varied though, and we added water so that the solution was always 10mL.

we tested 10mL, 7mL, 5mL and 3mL, and made sure that the solution was at 37*C before we started the reaction. we timed it, but did not finish.

damn.

bio (1022) - MaB: [p] effect of temp on enzymes

experiment today, testing the rate of reaction of rennin in milk. me and paul's experiment didn't really go anywhere, then we found it it wasnt meant to.

we added 1mL of rennin (enzyme) to 10mL of milk at diff temperatures. 10, 37 and 50. our control was just milk sitting on its own.

only the 37 was meant to clot though, coz 10 is too cold, the enzymes would be inactive, and the 50 would denature the enzymes.

we altered temperature of milk in test tubes by keepnig them in beakers of water of varying temperatures, measuring the MILK's temperature with a thermometer. each reaction was timed using a stopwatch, but not recorded coz it went nowhere -.-