Lecture 6 Flashcards
How many chromosomes do we have? how many pairs do we have?
46 chromosomes
23 pairs
What makes up a chromosome?
chromatin coils around histones which form the DNA double helix that condenses to make up chromosomes.
What contain all your genetic information?
Chromosomes
What are genes?
Sections of DNA that control your physical characteristics
In what way are genes like a recipe?
It’s like baking a cake. You can take the same base recipe and change it to make different flavours
What are alleles?
A variation of a gene (Ex: a gene for eye colour could have alleles for blue, brown or green)
If we get one allele for eye colour from one parent and one allele from the other parent. What determines your eye colour?
The relationship between the alleles. In a dominant/ recessive relationship, If a person carries both alleles, the dominant allele will show, not the recessive allele.
What is an example of a Dominant trait?
What is an example of a recessive trait?
How do you show this relationship when writing?
A dominant trait is shown by an upper case letter (Ex:
B = brown eyes)
A recessive trait is shown by a lower case letter (Ex: b = Blue eyes)
What do we use to determine the frequency of certain characteristics in children using parental genotypes?
Punnett squares
What is the difference between a genotype and a phenotype?
A genotype is the genetic code for a trait (Ex: BB or Bb or bb) (inherited)
The phenotype is the way that trait presents (Ex: blue eyes or brown eyes) (interaction of gene and environment, can be changed)
What 2 factors can affect phenotype?
Gene disorders and interactions with your environment
Can identical twins look different? Why or why not?
Twins can start off looking identical but different lives and stresses can cause physical differences based on environment they’ve been in (Ex: smoker vs non-smoker)
What is range of reaction theory?
our genes set limits on a given characteristic, our environment determines to which degree they are expressed (Ex: genetic potential for high IQ may not be fostered as a result of uneducated parents and socio-economic status therefore limiting IQ in developmental stages)
What is gene environment correlation?
As we show genetic propensity for something, we are more likely to continue to gravitate towards those environments. Our environment then determines to which degree our genes are expressed. (Ex: is good at soccer at young age, is pushed into soccer rather than dance. Gets better at soccer, never put in a position to be good at dance).
In a healthy environment, is someone with a genetic predisposition for schizophrenia more likely to develop it?
no. Someone with a predisposition to schizophrenia is much more likely to develop it in a stressful environment though.
Can stressful environments affect our genes? Why?
Yes. When we experience acute stress we release cortisol which can result in dormant parts of our genetic code to be expressed (environmental stresses can “turn on” dormant genes)
What is an example of Epigenetics?
A pregnant person smoking changes
– their unborn child’s DNA
– the DNA of the unborn child’s children (because all eggs a female will have are developed in the womb)
What is a neuron?
Simplest building block of our biological electric grid (not actually electrical)
Are we born with all our neurons?
Yes
Our we born with all of our neuron connections?
No
What is the anatomy of a neuron?
Myelin sheath, Soma, dendrites, axon, axon buttons, glial cells
What is the soma? What does it do?
The cell body: (Large part before the dendrites)
- processes info
-is the staging ground for the neural signal
What is the axon? What does it do?
(Long part connecting axon buttons and soma)
- - Transmits info from one part of neuron to other
What are the axon buttons? What do they do?
(Branches after the axon)
Send signal to the next neurons
What are the dendrites? What do they do?
(Branches off of soma, front of the neuron)
- receives and transports information to the cell body
What do glial cells?
- some give food
- help repair
-provide structure
What are the myelin sheaths? What do they do?
(The fatty bits on the axon)
-helps the signal travel faster
- the more you use the neuron the thicker the myelin sheath.
How do neurons communicate
Conduction
Transmission
What ions are in the extracellular fluid of a neuron?
positive sodium ions move into the soma giving it a positive charge.
Is a neural signal an electrical signal? Why?
No. It is a series of action potentials, not electrical because it does not go down axon in one fluid motion.
