Genetic variation and evolutionary Part 3

random stuctural modification

• of a gene or chromsosome that are changes in the information contained in the genetic material

• origin→ mutation

• DNA or RNA

potential causes

• error during DNA replication, exposure to radiation or some chemicals

• adaptive, random events and some benefit and some don’t

neutral mutation

• most common mutation

• neither increase or decrease fitness

heterochromic

two different color eyes

detrimental mutation

mutation that decrease fitness (not always fatal)

lethal mutation

mutations that lead to early death

beneficial or adaptive mutation

slow addition and some neutral or good mutations

heritability of mutations

• mutations can occur either in somatic or germinal cells

• mutations in somatic cells (not hertiable) can influence an individual’s survival; but can’t passed on to future generations

germ line mutations

occur in reproductive and maybe hertiable

base substitution

change one letter lead to new genetic code/atom

synonymous substitution

nucleotide subsitiutions that don’t result in a change in amino acid

frame mutation

the addition or loss of nucleotides can change the reading frame altering the colon sequence

insertion

base pairs added to a DNA sequence

deletion

loss of some base pairs from DNA sequence

duplication

• part of the DNA sequence is repeated

• in some cases, the shift in reading force can lead to a premature stop codon, leading to truncated protein (not completed protein)

chromosomal rearrangements

modification of chromosomal structure during mitosis & meiosis, generating major changes affecteing large number of traits

reciprocal translocation

• exchange of genes between non-homologous chromosomes

• alters chromosomal rearrangements

recombination or crossing over

during meiosis, homologous chromosomes exchange some genetic material with each other

independent assortment in meiosis and mitosis

50/50 chance of getting chromosome gene from mom or dad

random fertilzer

the unpredictable, chance fusion of a specific sperm with a specific egg during sexual reproduction