2nd semester exam review Flashcards
what happens during crossing over
homologous chromosomes exchange segments of DNA during prophase 1
what’s the difference between haploid and diploid?
haploid has 1 set of chromosomes
diploid has both sets of chromosomes
during what phase of meiosis do tetrads form
prophase 1
what is the end product of meiosis
4 haploid cells (gametes)
what is a tetrad
4 sister chromatids formed by chromosomes lining up in synapsis
what is the law of independent assortment
it states that genes for different traits can segregate independently during formation of gametes
what is polygenic inheritance
inheriting a trait that is controlled by more than one gene (skin color)
what factor influences the change in color in the arctic fox
environmental factors (temperature, terrain)
which generation did Mendel allow to self pollinate
F1 generation
what type of trait is blood type
multiple alleles (controlled by 2 alleles)
what was Roland franklins contribution to the discovery of DNA
she worked independently with X-ray diffraction which helped contribute to Watson and crick’s discovery of DNA being a double helix
what is a codon
in mRNA it codes for a specific amino acid
consists of 3 nucleotides
what is DNA replication
replication of DNA where the strand separate and appropriate base pairs are plugged in
what does the mRNA copy
the recipe from DNA so proteins can be made
who figured out the shape of DNA
James Watson and Frances crick
what is the role of tRNA in protein synthesis
it transfers amino acids to the ribosomes
what is the function of telomerase
in rapidly dividing cells it helps to prevent damaged or lost genes
what happens during translation
tRNA translates the genetic code by delivering amino acids to the ribosome
anti codons pair with codons
codons come along to form long chains
where does translation and transcription take place in eukaryotes
translation- ribosome
transcription- nucleus
what was chargaffs contribution to the study of DNA
he discovered that the % of guanine and cytosine were almost equal in any DNA sample (adenine and thymine also) which led to the principle of base pairing
what is a promoter
regions of DNA with specific base sequences
where RNA polymerase binds to
what is a bacteriophage
a kind of virus that infects bacteria
can codons code for the same amino acid
yes
what kind of cells are used to make dolly
cloned cells (nucleus is removed & another is inserted into egg)