well we finished the experiment today too, we wrote down results. essentially the plants that were watered grew many, large leaves, as opposed to pretty much none on the unwatered plants. also the ones that got more sunlight had bigger leaves.
after that we just did a bit of revision on DNA.
deoxyribonucleic acid, is composed of nucleotides. a nucleotide is composed of a sugar (deoxyribose) a nitrogen base (adenine, thymine, cytosine and guanine) and a phosphate that bonds the sugar to another sugar.
RNA is pretty much the same, but unlike DNA that is a double helix, RNA is a single strand, and it has uracil instead of thymine.
random note: humans have been around for like a million years, and cyanobacteria like dominiated for liek 2 billion years, dinosaurs for like 400 million.
mitosis produces 2 daughter cells taht are identical, and have a set of chromosomes each (46 for people) these are somatic cells.
the opposite of somatic cells are gametic cells, or gametes (sex cells) they only possess half the amount of chromosomes each (23) and they combine to create the offspring's genes and stuff. this is what causes variation, and hence, evolution.
Showing posts with label blueprint of life. Show all posts
Showing posts with label blueprint of life. Show all posts
Thursday, April 22, 2010
Wednesday, March 17, 2010
bio (0317) - BoL: DNA
DNA: deoxyribonucleic acid
it's what stores information and dictates how an organism is.. built? DNA is found in the chromosomes within the nucleus.
the two helixes are made of sugars (deoxyribose - ribose that has been deoxygenated) that are held together by phosphates. ribose is a pentose, which means it's a sugar that consists of 5 carbon atoms.
the four nitrogen bases are: adenine & guanine (purines) aka the big ones and thymine and cytosine (pyrimidine) aka the small ones. adenine and thymine are always paired up and joined by 2 hydrogen bonds, and guanine and cytosine are always paired up, joined by 3 hydrogen bonds.
a base attached to a sugar and phosphate is called a nucleotide. DNA consists of many nucleotides all joined up together.
DNA replicates when the double helix is split. since the bases only have one possible pair each, the DNA components floating around join up to make separate pairs for the split helixes, thus duplicating the original
it's what stores information and dictates how an organism is.. built? DNA is found in the chromosomes within the nucleus.
the two helixes are made of sugars (deoxyribose - ribose that has been deoxygenated) that are held together by phosphates. ribose is a pentose, which means it's a sugar that consists of 5 carbon atoms.
the four nitrogen bases are: adenine & guanine (purines) aka the big ones and thymine and cytosine (pyrimidine) aka the small ones. adenine and thymine are always paired up and joined by 2 hydrogen bonds, and guanine and cytosine are always paired up, joined by 3 hydrogen bonds.
a base attached to a sugar and phosphate is called a nucleotide. DNA consists of many nucleotides all joined up together.
DNA replicates when the double helix is split. since the bases only have one possible pair each, the DNA components floating around join up to make separate pairs for the split helixes, thus duplicating the original
Tuesday, March 16, 2010
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.
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.
Wednesday, March 10, 2010
bio (0310) - BoL: sex-linked genes
some alleles can only be found on the sex chromosomes: X and Y
note that the Y chromosome is significantly shorter than the X chromosome (this could be due to some kind of evolutionary change) and as a result carries less alleles.
also, as a result, it means if there is an allele for a certain trait or disease on the X chromosome for a man, there would be nothing on the Y and the X would determine stuff. catch it? because of this, men can't carry certain things, they can either just have the disease or not.
if you try draw punnet squares for two alleles and sex-linking them.. the result is 4 babies, with 2 male and 2 female, and the genotypes mixed accordingly. not that 4 babies are born, that's just the chance.
this is hard to explain.. but i understand it so that's what's important hahaha.
there are cases that a trait can be carried on the Y only, but it's not taht common. it's usually on the X since the X is the epic long one.
in the case of recessive diseases. this is why females can carry the disease but not necessarily have it. if they had a heterozygous pair-up for that disease, it'd mean they can carry the disease but not have it.
in the case of men, if they received one of the X chromosomes from their mother (they'd have to since they receive Y from their father) then either they have it (receive recessive gene, nothing on Y to counter it) or they dont (receive dominant gene, no issue there)
note that the Y chromosome is significantly shorter than the X chromosome (this could be due to some kind of evolutionary change) and as a result carries less alleles.
also, as a result, it means if there is an allele for a certain trait or disease on the X chromosome for a man, there would be nothing on the Y and the X would determine stuff. catch it? because of this, men can't carry certain things, they can either just have the disease or not.
if you try draw punnet squares for two alleles and sex-linking them.. the result is 4 babies, with 2 male and 2 female, and the genotypes mixed accordingly. not that 4 babies are born, that's just the chance.
this is hard to explain.. but i understand it so that's what's important hahaha.
there are cases that a trait can be carried on the Y only, but it's not taht common. it's usually on the X since the X is the epic long one.
in the case of recessive diseases. this is why females can carry the disease but not necessarily have it. if they had a heterozygous pair-up for that disease, it'd mean they can carry the disease but not have it.
in the case of men, if they received one of the X chromosomes from their mother (they'd have to since they receive Y from their father) then either they have it (receive recessive gene, nothing on Y to counter it) or they dont (receive dominant gene, no issue there)
bio (0309) - BoL: pedigree charts
just get used to using key etc, and sticking to it. taht has been an issue in the past apparently.
conventionally its just squares and circles that represent male/female respectively, and they are shaded in black if they are affected by the named heriditary trait.
know how to make family trees right?
join up parents with line and draw line down to children. children can link to other partners and have more children..
etc.
have to be able to read them too and draw genotypes from looking at these things
i cant really say anything much here.. it's more a visual thing than a verbal thing but yeah.
conventionally its just squares and circles that represent male/female respectively, and they are shaded in black if they are affected by the named heriditary trait.
know how to make family trees right?
join up parents with line and draw line down to children. children can link to other partners and have more children..
etc.
have to be able to read them too and draw genotypes from looking at these things
i cant really say anything much here.. it's more a visual thing than a verbal thing but yeah.
Saturday, March 6, 2010
bio (0305) - BoL: punnett squares
simple concept. have the male alleles on the top, and the female down the side. so there's a 2x2 box corresponding to these alleles, which decides the possibilities for genotypes.
conventionally, something Aa and aA are the same, but the dominant allele comes first.
eg something like
\...|.A...|...a...|
....________
.A.| AA | Aa |
__________
.a. | Aa | aa
thats kinda confusing but yeah
take note taht often certain features are affected by a number of genes, not just one. and if the two alleles of the same gene appear on a single chromosome, well then it doesnt get split during meiosis then.
one more thing.
organisms with two same alleles for the same gene are known as homozygous for that feature, likewise having two different alleles makes them heterozygous
conventionally, something Aa and aA are the same, but the dominant allele comes first.
eg something like
\...|.A...|...a...|
....________
.A.| AA | Aa |
__________
.a. | Aa | aa
thats kinda confusing but yeah
take note taht often certain features are affected by a number of genes, not just one. and if the two alleles of the same gene appear on a single chromosome, well then it doesnt get split during meiosis then.
one more thing.
organisms with two same alleles for the same gene are known as homozygous for that feature, likewise having two different alleles makes them heterozygous
Thursday, March 4, 2010
bio (0303) - BoL: genetic manipulation
watched a video on how technology has evolved so that we can manipulate genetics ourselves.
the video actually started talking about mendel, but already enough notes on him, something interesting to note though is that the monks burnt his work after he died, coz they thought it would be of no use to anyone.
anyway.. humans have been manipulating genetics for generations without realizing, with methods such as selective breeding, taking the best qualities of crops or livestock and passing it onto offspring. genetic manipulation nowadays is just a shortcut really.
some interesting examples would include the tilapia fish, which has had genes from salmon transferred to it so that they are bigger. also the banana plant (herb not tree) can have genes inserted in them that prevent bananas from going bad while on the shelves of stores.
genes can be transferred right from the embryonic stages, in which case the genes are fired into the nucleus of cells using a high-powered gun.
anyway im not exactly sure if i got allt he wordings right, since we didnt take notes. but i think here's the general geist.
the video actually started talking about mendel, but already enough notes on him, something interesting to note though is that the monks burnt his work after he died, coz they thought it would be of no use to anyone.
anyway.. humans have been manipulating genetics for generations without realizing, with methods such as selective breeding, taking the best qualities of crops or livestock and passing it onto offspring. genetic manipulation nowadays is just a shortcut really.
some interesting examples would include the tilapia fish, which has had genes from salmon transferred to it so that they are bigger. also the banana plant (herb not tree) can have genes inserted in them that prevent bananas from going bad while on the shelves of stores.
genes can be transferred right from the embryonic stages, in which case the genes are fired into the nucleus of cells using a high-powered gun.
anyway im not exactly sure if i got allt he wordings right, since we didnt take notes. but i think here's the general geist.
Monday, March 1, 2010
bio (0301) - BoL: gregor mendel
an austrian monk living in a monastery in what is now czechoslovakia. he published his findings about genetics in 1865, but his work was not realized until 1900. nowadays he is known as the father of genetics.
for years mendel tested the breeding of certain characteristics among peas.
his method worked because he tested for only one variable at a time, with only 2 possible outcomes, with no intermediates. he used purebred varieties to ensure validity, and used many peas of each kind per trial. his findings used numbers and statistics, which wasn't common among biologists at the time, but it made his findings better understood.
he tested factors such as:
tall x short
axial x terminal flowers
smooth x constricted pods
round x wrinkled seeds
his findings were that usually, the results in the 2nd generation after the purebred parrents favoured one characteristic over the other in a ration of 3:1. he realized that this is because one "factor" was dominant over the other.
consider an example tall (T) peas bred with short (s) peas
there are 4 possibilities of "factor" (allele) combinations:
TT Ts sT ss
since tall (T) is dominant, the three results with a T in them will result in tall peas, where as only the ss pea variety would result in short-stemmed peas.
for years mendel tested the breeding of certain characteristics among peas.
his method worked because he tested for only one variable at a time, with only 2 possible outcomes, with no intermediates. he used purebred varieties to ensure validity, and used many peas of each kind per trial. his findings used numbers and statistics, which wasn't common among biologists at the time, but it made his findings better understood.
he tested factors such as:
tall x short
axial x terminal flowers
smooth x constricted pods
round x wrinkled seeds
his findings were that usually, the results in the 2nd generation after the purebred parrents favoured one characteristic over the other in a ration of 3:1. he realized that this is because one "factor" was dominant over the other.
consider an example tall (T) peas bred with short (s) peas
there are 4 possibilities of "factor" (allele) combinations:
TT Ts sT ss
since tall (T) is dominant, the three results with a T in them will result in tall peas, where as only the ss pea variety would result in short-stemmed peas.
Sunday, February 28, 2010
bio (0224) - BoL: pentadactyl limb
today was about observing the similarities in the forelimbs of different organisms, to be specific.. the pentadactyl limb. these similar bone structures suggest that these animals evolved from a common ancestor, but adapting to suit their environment.
generally it consisted of a humerus, an ulna and radius, a carpal and 5 digits (fingers/toes, etc)
mammals, birds, reptiles and amphibians share this common feature.
generally it consisted of a humerus, an ulna and radius, a carpal and 5 digits (fingers/toes, etc)
mammals, birds, reptiles and amphibians share this common feature.
bio (0218) - BoL: [p] natural selection
did a prac today using printouts of moths.
it seems that white moths were the favourable kind (probably polar regions) over black or their offspring grey.
it was just a model, that showed breeding species, and also how different organisms are randomly "naturally selected" and thus killed off.
it wasnt long before the black population died out, since they were the favourable kind to be eaten according to our chance wheels, in which 3/6 were black, 2/6 were grey and 1/6 were white.
see? bias much hahaha
it seems that white moths were the favourable kind (probably polar regions) over black or their offspring grey.
it was just a model, that showed breeding species, and also how different organisms are randomly "naturally selected" and thus killed off.
it wasnt long before the black population died out, since they were the favourable kind to be eaten according to our chance wheels, in which 3/6 were black, 2/6 were grey and 1/6 were white.
see? bias much hahaha
bio (0217) - BoL: evolution
BLUEPRINT OF LIFE!
hurrah new subject.
we already know how evolution goes by darwinism ideas: natural selection.
there is always variation within a population, but this is beneficial if the environment changes. offspring with favourable characteristics to suit the environment breed more offspring with those characteristics.
natural selection ie. survival of the fittest.
generations continuously pass on these favourable characteristics, and as environments change, so do adaptations, leading to evolution of species completely.
hurrah new subject.
we already know how evolution goes by darwinism ideas: natural selection.
there is always variation within a population, but this is beneficial if the environment changes. offspring with favourable characteristics to suit the environment breed more offspring with those characteristics.
natural selection ie. survival of the fittest.
generations continuously pass on these favourable characteristics, and as environments change, so do adaptations, leading to evolution of species completely.
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