exam 1:mendelian inheritance Flashcards
what is genetics?
the science of heredity
what is heredity?
the passing of biological, genetic info (DNA) to offspring
what type of “ploid” are humans
diploid (2 sets of chromosomes)
-1 set from mom
-1 set from dad
how do the chromosomes become gametes
SPLIT–> one set of chromosomes goes to one gamete & the other set goes to the other gamete
(1 from mom and 1 from dad)
what bond holds the 4 DNA bases tgt
hydrogen bond
-not a type of covalent bond
-held tgt by electronegativity (opposite charges)
G-C (3 hydrogen bonds)
A-T (2 hygrogen bonds)
what type of gene makes up the majority of the genome?
non-coding gene
gene/locus
specific region of DNA
(may or may not code for polypeptide)
where are the genes/loci located
on chromosomes
what is a genome
all chromosomes within a cell
the order of DNA nomenclature
gene/locus–>chromosomes–>genome
what is the central dogma
DNA replication—> DNA
DNA —-transcription—>RNA—translation—> Protein
how are amino acids codes for
by triplets of DNA/ codon of DNA nucleotides (transcribed to RNA)
what are polypeptides made up
string of amino acids
-held tgt by peptide bonds
what are proteins made up of
one/more polypeptides folded tgt (3D structure)
why do shapes of proteins matter
determine the function
what part of aa that drives its function
the r-groups (how polypeptides folds)
facts abt proteins
-drives biological functions in all living organisms
-DNA codes for polypeptides which form proteins
-SO, DNA= instructions for biological function (blueprint of life)
“junk” DNA vs coding DNA
-theres no junk dna, they are non-coding DNA
-coding DNA: coding DNA, gets into proteins (transcribes+ translated)
*What’s the important of having both DNA and RNA?
1.having both allows for genetic amplification
-making multiple copies of a gene
2.stability:
-RNA unstable, mutates easily (have 2 OHs groups)
-DNA stable, only 1 Oh group
central dogma
DNA —transcription—->RNA—-translation—>protein
all living things follow it
->suggest we are evolved from a common ancestor
all living things only have 4 nucleotides, 20 aa’s, and evolved from the single ancestor, how is there diversity
genome evolution
-increase the complexity of gene due to gene dupilcation=
as long there are multiple copies and a gene and those genes continue to serve a purpose, mutations are likely to occur
-gene rearrangements where the genes are similar but have differnt products
where duplication occur for genome evolution? how do they interact?
occurs in
1: errors in DNA replication
2. uneven crossing over during meiosis (recombinant: homologs chromosomes-> equal and opposite)
interact by crossing over
what did gregor mendel studied and why?
he use pea plants and predict specific physical features passed from parents to offspring
why? bc he wanted to increase yield of the pos traits and avoid the neg
what was gregor mendel’s greastest contribution?
discovered a predictable pattern of inheritance based on random (what offspring would look like based on the parents) assortment of “genetic particles” (genes)
artificial selection
based on humans selection where organisms w/ undesirable traits are killed and bred those with desireable traits
misconceptions of inheritance
- one parent contributed more than the other to the offspring (unequal contribution)
-did reciprocal crosses to dispell myth - parental traits blended tgt in offspring and were permanently changed
“blending inheritance”’
why did mendel work with peas
- easy to grow
- easy to control fertilizations
- easy to produce and screen large numbers of offspring quickly
*traits are “mutually exclusive”-“either/or”traits (cant be both)
unlikely continuously varible:everything in between
what does true breeding mean
when self fertilized, parents always produce offspring look exactly like themselves
homologous for the trait
*mendel 1st law: law of segregation
during gamete formation,
a pair of alleles from each parent separate and give the offspring one alle
*def:
-2 alleles for each trait separate when gametes are formed (only 1 alle is contained in each gamete)
-alleles reunite at random- 1 from each parent via fertilization
mendels crosses predict phenotype, how can you tell their genotypes
test cross
*mendel’s 2 law: law of independent assortment
during gamete formation, diff pairs of alleles separate (assort) independenly
-presence of 1 specific allele does not affect presence of another
the different between mendels 1st and 2nd law
what is mendelian inheriance
1 gene control 1 trait
how to we follow the pattern of inheritane( like diseases) in humanss
pedigree analysis
pattern of inheritance: recessive
2 unaffected parents, one or more affected child
-this means that the homozygous recessive genotypes have the “disease”
pattern of inheritance: dominant
2 affected parents, at least one unaffected child
-this means that the ones that is affceted are homozygous recessive
