study guide for unit 2 Flashcards
genotype
The actual genetic make up of an organism that it gained from its parents
phenotype
The way an organism looks based on its genetics/genotype (physical appearance)
Gregor Mendel
father of genetics. He cross pollinated, two pea plants, purple flower with white flower. first generation got only purple flowers produced, second generation, one white pea plant was produced. *the proved dominant and recessive alleles.
how many alleles is hh
1
how many alleles is hs
2
what is mendels law of dominance?
two choices for each trait, and if both jeans are present, one expresses over the expense of the other.
what is mendels law of parental equivalence?
The sex of the parent does not determine if or if not, the dominant trait is expressed.
what is the gene locus?
The place on a chromosome, where a gene is found.
what is a carrier
A person with an inactive trait that can pass on to future generations.
incomplete dominance?
One allele will not overpower the other, instead, they’ll mix.
Example: red + white flower = pink flower
co dominance?
One allele will not overpower the other, instead both characteristics are displayed in their complete form.
Example: brown and white cow = white cow with brown dots
polygenic inheritance?
The inheritance of traits that are influenced by multiple genes.
example; eye colour is influenced by 15 genes
lethal alleles?
Versions of genes that can cause severe health problems, or even death.
(these alleles are often recessive)
linked genes?
genes that are located close to each other on the same chromosome, because they are so close together they tend to be inherited together more often than not.
Example: red hair and freckles.
chromosome?
each chromosome is made of protein in a single molecule of DNA. Chromosomes carry the genes which responsible for your hereditary characteristics.
23 pairs, 46 chromosomes in humans.
karyotype?
shows the number and appearance of chromosomes in an organism.
what is mitosis?
A form of eukaryotic cell division that produces two daughter cells with the same genetic components as a parent. One diploid parent cell (2n) = 2 diploid daughter cells (2n)
do sex cells undergo mitosis OR meiosis?
meiosis ONLY
what are the steps of IPMAT mitosis
INTERphase- DNA replication (chromosomes duplicate. happens before mitosis
PROphase- chromosomes condense; nucleus starts to breakdown, allowing chromosomes to move freely.
METAphase- MIDDLE stage; chromosomes align at the centre of the cell.
ANAphase- AWAY; spindle pulls sister chromatids to opposite poles.
TELOphase- TWO(2) cells; the cytoplasm begins to split in half, spindles disappear & nucleus begins to reform.
what is cytokinesis?
Cell divides, two daughter cells are formed
what is meiosis?
A form of eucaryotic cell division that produces 4 daughters cells with HALF genetic information as a parent cells. Sex cells (ova & sperm) divide using the process of meiosis. One diploid parent cell (2n) = 4 haploid daughter cells (n)
what are the steps of meiosis 1?
INTERphase 1- the state of the cell before meiosis.
PROphase 1- chromosomes, replicate, homologous chromosomes pair together.
METAphase 1- chromosomes align at the centre of the cell, homologs paired.
ANAphase 1-spindles pull homologous pairs opposite poles.
TELOphase 1-spindle disappear, nucleus starts, reforming, cell division begins.
what is the importance of meiosis 2?
two haploid daughter cells are formed (3 chromosomes each with 2 chromatids) now only chromosomes remain (no homologous pairs)
what are the steps of meiosis 2?
PMAT (no interphase in meiosis 2)
PROphase 2- nucleus, dissolves, spindles form.
METAphase 2- spindles attach and centre chromosomes in the middle of the cell.
ANAphase 2- spindles pull chromosomes apart, and drag them to opposite poles.
TELOphase 2- nucleus, reforms, cells divide, and four haploid daughter cells are formed.
what is the importance of meiosis?
only process that produces sex cells/gametes. It is a type of cell division that produces cells with HALF the chromosomes as the parent cell.
* this processes necessary for sexual reproduction*
define diploid
having two complete sets of chromosomes, when a cell has two complete copies of each chromosome, one for each parent.
example: humans have 46 chromosomes, 23 from each parent parent.
define haploid
diploid DIVIDED by 2
having only one set of chromosomes, when a cell only has one from each pair of homologous chromosomes. When a cell has half the number of chromosomes to diploid cells.
define polyploid
When a cell has multiple sets of chromosomes.
how many pairs do each have? diploid? haploid?
diploid # =12
haploid # =6
a disease when you have a damaged gene?
Hemophilia
effects; bleeding in joints, unable to form blood clots at wounds, bleeding in head causing seizures.
what is a disease when u have a damaged chromosome?
Tay-Sachs disease
effects; seizures, vision and hearing loss, paralysis
what is a disease when you have a missing chromosome?
Turner Syndrome
effects; shirt height, fail to develop ovaries, heart defects
what us a disease when you have an extra chromosome?
down syndrome
effects; flattened face, small head, short neck, poor muscle tone, protruding tongue
what is replication?
DNA unwinds, two halves will separate. free floating nitrogenous (AT, CG) bases will attach to DNA, a duplicate of the model will be made in the nucleus.
it can make 2 daughter cells that are identical to parents. How? A&T attach, C&G attach, 2 identical strands.
what are the two steps to making proteins?
Transcription & Translation
what is Transcription?
just like replication, DNA unwinds and two halves seperate. this time, free, floating, mRNA bases join with the DNA bases. the process of making an mRNA copy of a genes, genetic DNA sequence to send outside of the nucleus to the ribosomes. (proteins)
what is Translation?
The process of translating the DNA code from the messenger(mRNA) and turns into a series of amino acids bound together by peptide bonds. Amino acids need three bases to code for a protein (trait). tRNA anticodons will attach to the mRNA codons.
what DNA, replication, RNA(transcription) look like side by side using anticodons.
DNA- CGGTATTGCC
replication- GCCATAACGG
transcription (RNA)- GCCAUAACGG
in RNA cannot use T so we use U
what factors control genetic expression? specifically genetic factors?
sometimes one gene is needed to start the actions of another gene, these genes are called modifier genes.
what factors control genetic expressions? specially environmental factors?
different environmental conditions can affect the expression of genes. things like temperature, sunlight, chemical exposure, etc.
what is missense mutation?
a change in one DNA base pair
what is nonsense mutation?
a change in one DNA base pair resulting in a premature stop codon.
what is silent mutation?
when the substation doesn’t change the amino acid.
what is insertion?
when a piece of DNA gets added to the DNA code.
what is deletion?
a piece of DNA gets deleted/removed from the DNA code.
what is duplication?
DNA is abnormally copied one or more times.
what is a frame shift mutation?
changed reading frame from the code,reading pattern gets moved over.
what is repeat expansion?
a group of 3 DNA bases (codon) gets repeated.
beneficial mutations?
can lead to new traits and adaptations that increase an organisms chance for survival and reproduction.
harmful mutations?
an cause genetic disorders and decrease an organisms fitness.
what is DNA proofreading?
the job of an enzyme called DNA polymerase. the 2 stranded molecule passes through the DNA polymerase after replication is complete. if the wrong base has been inserted and the DNA polymerase can detect and replace the missing base.
DNA repair. what is direct repair?
when a thymine dimer is detected, DNA polymerase breaks up the dimer and pushes us down to complete the correct base. This process does not require a template for replacement.
what is nucleotide excision repair?
a collection of proteins travel down the DNA strand looking for damage. Once damage is detected, enzymes attach to the damage and cute it out. It is then rebuilt by the DNA polymerase.
fact about damaged recessive genes
damaged recessive genes can never be eliminated from a population because some individuals are carried of the gene, even if it isn’t shown. The gene can be passed onto multiple generations without being visible, until it is paired a similar recessive gene.
what is the purpose of the Human Genome Project?
the primary goal of the genome project was to identify all genes present in the human genome.
what were the accomplishments of the Human Genome Project?
played an important role in helping us understand human evolution. the project improved diagnosis’s and diseases, detected mutated genes earlier that could lead to any disease and improved gene therapy.
what is the Hardy-Weinberg principle?
a concept in population genetics that helps us understand how genetic traits are maintained in a population over time. Mutations, migration and selection (traits becoming more or less popular in a population over time) are all factors that disrupt this principle.
what is a genetic drift?
a process in which random changes in gene frequencies occur in a population. The hanging of allelic frequencies due to sampling errors.
key points in the biotech revolution video
- cloning cattle to produce more prize-winning animals in auctions
- cloning organs so that we can have a ready made supply of organs to transplant
- we can colon embryos and gametes so that infertile couples can have children
what is DNA profiling?
a technique used to identify individuals based on their unique DNA patterns.
what is the law of segregation?
every individual possesses two alleles and only one allele is passed on to the offspringz
what is the law of independent assortment?
the inheritance of one pair of genes does NOT influence the inheritance of another pair.
