DNA/Hereditary test :| Flashcards
What type of macro molecule is DNA/RNA?
Nucleic Acid
What are nucleic acids made of
Nucleotides
What is a nucleotide made up of?
A phosphate group, a sugar, and a nitrogen base
What is Thymine replaced with in RNA?
Uracil
What are the base pairs?
Adenine with Thymine/Uracil, Cytosine with Guanine
What is the backbone of DNA/RNA made of
A (deoxy)ribose sugar and a phosphate
What binds the phosphate and nitrogen bases together?
Sugar
What’s the difference between pyrimidine and purine?
Pyrimidine is a base with a single ring. Purines are bases with two rings.
What are the sugar and phosphate bonds between nucleotides called?
Phosphodiester bonds
what does tRNA do?
(Transfer RNA) It carries amino acids
what does mRNA do
(messenger RNA) used to build protein
what does rRNA do
(ribosomal RNA) makes up parts of ribosomes
What’s the difference between eukaryotic cells and prokaryote cells when it comes to DNA and RNA?
In eukaryotic cells, the DNA/RNA can be found in the nucleus. In Prokaryote cells, DNA/RNA is only in the cytoplasm.
What are the stages of mitosis.
Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
What does the helicase do
Unzips the DNA
What does DNA polymerase do
Adds complementary free nucleotides to both unzipped strands of DNA
What does semi conservative mean
It describes replication where each copy of DNA reserves one strand from the original DNA
DNA Polymerase reads the DNA template strand from…
the 3’ end of the DNA molecule to the 5’ end
What forms the lagging strand of DNA?
Okazaki Fragments
define the enzymes used in DNA replication
helicase: unzips the DNA
primase: adds RNA primers to DNA strands
polymerase III: adds new nucleotides to DNA strands
polymerase I: replaces RNA primers with DNA nucleotides
ligase: attaches the new DNA fragments with the rest of the strand
what joins amino acids together
polypeptide chains
what is transcription
the DNA code is transcribed into an mRNA strand
what is translation
the mRNA strand is translated into a protein
Where does transcription and translation take place in prokaryotic cells?
The Cytoplasm
Where does translation occur in eukaryotic cells?
The Cytoplasm
Where does transcription occur in eukaryotic cells?
The Nucleus
what are the steps of translation
- mRNA attaches to a ribosome in the cytoplasm.
- the ribosome lines up complementary tRNA molecules (the anti-codons).
- the amino acids on the tRNA connect with peptide bonds as this happens, therefore creating proteins
what are the steps of transcription
- RNA polymerase attaches a promoter sequence of DNA
- it starts adding complementary RNA nucleotides (the mRNA)
in eukaryotes, what are the non-coding regions of the mRNA called? how are they removed
introns; they are removed through a process called splicing
if a mutation is helpful then the # of individuals with the new phenotype will…
increase
what do genetic mutations cause (long term)
natural selection/evolution
what are the three types of mutations? summarize them
substitution: one base is exchanged or swapped for another base
insertion: one or more bases are inserted, making it longer
deletion: one or more bases are deleted, making it shorter
why can DNA mutations impact the proteins synthesized in a cell?
since DNA is used as a template to synthesize mRNA during transcription, a DNA mutation could cause the altered codons to code for a different amino acid, therefore a different or non-functional protein
what are the four types of mutation effects? summarize them
silent: the mutation has no effect on the amino acid coded for
missense: the mutation causes a codon to code for a different amino acid
frameshift: the mutation causes the “reading frame” of the mRNA codons to shift forwards or backwards, changing many amino acids
nonsense: the mutation causes a stop codon which terminates translation early
what are the four types of chromosomal mutations? summarize them
duplication: extra copies of genes are added to a chromosome
inversion: a section of the chromosome is flipped/reversed
deletion: a piece of the chromosome breaks off and is lost
translocation: a piece of one chromosome breaks off and attaches to another chromosome
when an organism has too many or too few chromosomes, it is called…
Aneuploidy
when an organism has more than two paired sets of chromosomes, it is called…
Polyploidy
gametes form through a process called…
meiosis
in meiosis, chromosomes stay attached until which division
the second division
a synapsis is…
2 pairs of sister chromatids
what causes the sister chromatids to become genetically different?
Crossing over
at the end of meiosis there are…
4 genetically different haploid cells
when gametes fuse, the resulting embryo is…
diploid
describe prophase in meiosis 1 and 2
in both meiosis 1 and 2:
- the nuclear envelope breaks down
- the centrosomes move to opposite poles
- the chromosomes condense and become visible
in meiosis 1:
- crossing over occurs between homologous chromosomes
describe metaphase in meiosis 1 and 2
in both meiosis 1 and 2:
- the spindle forms completely
in meiosis 1:
- homologous pairs of chromosomes line up in the middle of the cell
in meiosis 2:
- the chromosomes line up in the middle of the cell
describe anaphase in meiosis 1 and 2
in both meiosis 1 and 2:
- the spindle fibers begin to contract
in meiosis 1:
- the homologous chromosomes get separated by their centromeres to the poles
in meiosis 2:
- the sister chromatids get separated by their centromeres to the poles
describe telophase in meiosis 1 and 2
in both meiosis 1 and 2:
- nuclear envelopes start to reform around the groups of chromosomes
- the chromosomes start to decondense back into chromatin
describe cytokinesis in meiosis 1 and 2
in both meiosis 1 and 2:
- the cytoplasm physical divides, splitting each cell into two
in meiosis 2:
- the cells are now in interphase
summarize crossing over
during prophase I, homologous chromosomes pair up to form a tetrad.
the non-sister chromatids form chiasmata where they overlap.
here, parts of the chromatids break off and join the other chromatid.
alleles are exchanged, forming new genetic combinations
What is chromatin made of?
DNA and protein
What is the relationship between histones and DNA?
DNA is wrapped around histones
Why does DNA have to be tightly packed?
It must fit in the nucleus and is more easily separated during cell division
When a chromosome is duplicated, how many chromosomes and chromatids are there?
There is still one chromosome but there are now two chromatids
True or false; all the genes in your chromosomes are turned on
False
Karyotypes are an image of…
all of your chromosomes
What phase is a cell typically in when the picture is taken for a karyotype?
Metaphase
What are homologous pairs?
chromosomes of the same size that carry the same types of genes in the same order
How many pairs of autosomes do humans have?
22
Which sex chromosomes do males have? females?
Males have XY, females have XX
How many chromosomes does a human gamete have?
23
Haploid vs diploid
Haploid cells have one set of chromosomes while diploid cells have two
Does the father or mother determine sex?
Father
What proteins are DNA molecules wrapped around?
Histones
What is the structure of a nucleosome?
A strand of DNA wrapped twice around 8 histones, held together by a histone protein named H1
What is linker DNA?
Double-stranded DNA that connects nucleosomes together
what is the Central dogma of biology
DNA info only flows in one direction
How do these words match up: asexual reproduction, sexual reproduction, mitosis, meiosis
Meiosis goes with sexual reproduction and mitosis can be involved in both asexual
What does incomplete dominance look like?
When two traits mix
What does co-dominance look like
When two traits show at the same time
What’s the different between a square and a circle on a pedigree?
A circle is female, a square is male
Are males or females more likely to get sex linked traits
Males
What is Nondisjunction
the failure of the chromosomes to separate, which produces daughter cells with abnormal numbers of chromosomes
What is the universal donor in blood types?
type O
what is the universal receiver in blood types?
type AB
Where do chances for genetic variation increase in meiosis?
During independent assortment and crossing over
in a dihybrid cross, what is the ratio of offspring for two heterozygous parents?
9:3:3:1
what are recombinant types
when it doesn’t look like any of its parents and a new Gene is expressed
what are the monomers for macromolecules?
carbs: monosacchrides
proteins: amino acids
lipids: fatty acids
nucleic acids: nucleotides
what’s the difference between meiosis and mitosis?
mitosis produces two genetically identical “daughter” cells from a single “parent” cell, whereas meiosis produces cells that are genetically unique from the parent and contain only half as much dna
