GENETICS – Introductory Lecture
- Differences between individuals of the same species or between species are
explained by differences in the genetic makeup or the patterns of activity of genes.
- Genotype refers to the DNA makeup of an individual
- Phenotype refers to any characteristics, traits and processes in living organisms.
- Genes determine simple characteristics but also physiological functions, our
response to environmental changes and our ability to learn are all ultimately
encoded in our DNA.
- Many congenital conditions are caused by our particular makeup e.g diastrophic
dysplasia is characterised by severe deformities in the bones and cartilage resulting
in short limbs and overall stature.It is caused by mutations in the gene SLC26A2. This
gene encodes a protein which is important in the development of cartilage which
leads to abnormal bone formation.This gene is recessive meaning that both parents
need to be carriers of the faulty gene for the offspring to have the disease
- Our susceptibility to many diseases is determined by our genetic makeup. E.g Many
cancers have a genetic factor, our changes of being affected by Alzheimer’s and other
diseases are also partly determined by genetics.
IMPORTANCE:
- Genetics is the study of genes. Genetics have long been important for human
populations - Humans have long manipulated the genetics of many species we have
domesticated. This was been done through selective breeding whereby only those
individuals with the characteristics we prefer are allowed to breed. Over time, those
preferred characteristics become more common
- Maize is a nice example of the extreme reshaping of a crop during domestication by
humans. Maize exhibits strong differences from the original wild plants it evolved
from. The changes in maize during and since its domestication are to a large extent
the result of selective breeding.
- More recently, with the advent of genomics research, variants of maize have been
created through genetic modification which involves directly changing parts of the
genetic makeup in the lab rather than through selective breeding. The use of
genetically modified crops is controversial in may parts of the world because of
potential hazards to human health or to the genetic diversity of other plants in the
wild through contamination or over-competition from genetically modified crops.
- Modern genetics knowledge can help to understand the molecular mechanisms of
many diseases. For example, we now know that certain mutations in the BRCA1 and
BRCA2 genes (these are two genes not one) are associated with increased lifetime
chances of developing breast cancer and or ovarian cancer.
- Although, there is not known drug which can definitively counteract the effects of
the mutations in these two genes, women can opt to get tested to see whether they
are carriers of the mutated versions of either of these genes and be able to make an
informed choice over preventative treatment.
- Having a bad gene does not really mean that we have extra genes causing a
condition. In most cases “bad” genes simply refer to having a variant or version of a
gene which causes a gene to malfunction. The gene is present in all of us, but the
- Differences between individuals of the same species or between species are
explained by differences in the genetic makeup or the patterns of activity of genes.
- Genotype refers to the DNA makeup of an individual
- Phenotype refers to any characteristics, traits and processes in living organisms.
- Genes determine simple characteristics but also physiological functions, our
response to environmental changes and our ability to learn are all ultimately
encoded in our DNA.
- Many congenital conditions are caused by our particular makeup e.g diastrophic
dysplasia is characterised by severe deformities in the bones and cartilage resulting
in short limbs and overall stature.It is caused by mutations in the gene SLC26A2. This
gene encodes a protein which is important in the development of cartilage which
leads to abnormal bone formation.This gene is recessive meaning that both parents
need to be carriers of the faulty gene for the offspring to have the disease
- Our susceptibility to many diseases is determined by our genetic makeup. E.g Many
cancers have a genetic factor, our changes of being affected by Alzheimer’s and other
diseases are also partly determined by genetics.
IMPORTANCE:
- Genetics is the study of genes. Genetics have long been important for human
populations - Humans have long manipulated the genetics of many species we have
domesticated. This was been done through selective breeding whereby only those
individuals with the characteristics we prefer are allowed to breed. Over time, those
preferred characteristics become more common
- Maize is a nice example of the extreme reshaping of a crop during domestication by
humans. Maize exhibits strong differences from the original wild plants it evolved
from. The changes in maize during and since its domestication are to a large extent
the result of selective breeding.
- More recently, with the advent of genomics research, variants of maize have been
created through genetic modification which involves directly changing parts of the
genetic makeup in the lab rather than through selective breeding. The use of
genetically modified crops is controversial in may parts of the world because of
potential hazards to human health or to the genetic diversity of other plants in the
wild through contamination or over-competition from genetically modified crops.
- Modern genetics knowledge can help to understand the molecular mechanisms of
many diseases. For example, we now know that certain mutations in the BRCA1 and
BRCA2 genes (these are two genes not one) are associated with increased lifetime
chances of developing breast cancer and or ovarian cancer.
- Although, there is not known drug which can definitively counteract the effects of
the mutations in these two genes, women can opt to get tested to see whether they
are carriers of the mutated versions of either of these genes and be able to make an
informed choice over preventative treatment.
- Having a bad gene does not really mean that we have extra genes causing a
condition. In most cases “bad” genes simply refer to having a variant or version of a
gene which causes a gene to malfunction. The gene is present in all of us, but the
