Traits Flashcards
These are the building blocks of Amino Acids
Proteins
The sequence of amino acids determines the specific role of the protein
Just some facts
Do the 2 DNA strand separate for the protein to be read by the cell
Yes, it separates and the sequence of bases are read in order to form a specific protein
How many bases does it need to able to code for an amino acid?
3 - it is called a triplet
What are proteins made up of ?
It is made up of linked amino acids (long chain of amino acids that are chemically bonded together)
What causes Variation ? (relate it to the base sequence)
Different variants of a gene’s base sequence, produce different proteins. Therefore, a variation in a particular trait of a species.
*a slight difference will code for slightly different protein
What are Mutations?
a mutation is a change in the base sequence of a gene found along the DNA molecule. This may result to a new ALLELE for that gene
What are Mutagens?
- Chemicals (cigarettes and fatty foods)
- Ultraviolet Light (from the sun)
- Radiation (x-rays/ radioactive materials)
What is the difference between a harmful and beneficial mutation?
A harmful mutation code for modified proteins that do not function properly. This may have effect to person’s survival advantage.
On the other hand, beneficial mutations as it codes for a modified protein that functions better than the original. This may have an advantage to person’s survival
What will happen if a mutation occurs in a body cell (somatic) ?
The only cells affected are those produced by the mutated cell. It cannot inherited or passed on to an offspring
What will happen if a mutation occurs in a gamete ( sex cell - sperm or egg)?
This is the only time that the mutation can be inherited or passed on to an offspring. (if only that particular gamete is fertilised )
Ultimate source of Variation
Mutations
These are the FEATURES OF AN ORGANISM that are determined by genes.
Traits
How are genes inherited?
Each individual inherits 2 copies of each gene (one each from both parents)
Where are genes found?
They are found at a specific location of chromosomes. (locus).
This is always expressed even though only one copy is present. It is expressed in a capital letter.
Dominant
Expressed if both of these are present. (no dominant trait is present)
Recessive
What are genotypes?
the specific pairs of alleles that the organism carries for a particular trait (Bb, BB, bb) . It determines the phenotype.
They also mask the presence of recessive alleles
What are phenotypes?
They are the physical expression of the alleles carried
Alleles that are the same (BB, bb)
Homozygous
Alleles that are different? (Bb)
Heterozygous
When both of the alleles are in capital letters
it is Homozygous Dominant (BB)
When both of the alleles are in lowercase letters
It is Homozygous Recessive (Bb)
When one allele is a expressed in a capital letter and the other is a expressed in lowercase letter
It is Heterozygous
