module 3: genetic Flashcards
what is the genome
the entire set of genes within a organism
what is ploidy
The ploidy is the number of copies of the gene
what does n represent
the number of copies of the genome
what is haploid
n, one copy
what is dipliod
2n, 2 copies
what is triploid
3n, 3 copies
what is a chromosome
a structure that is comprised of proteins that is amde up of highly packaged DNA or RNA, that is wrapped around histones
where is the telomere, short arm, long arm and centromere and sister chromatids
where is the centromere
in the middle of the chromosome
what is the function of the telemeres
what is the function of the telemeremaintain the integrity of the chromosomes because it is difficult to replicate the end of a chromosome, therefore telomers make sure the chromosomes do not get shorter and shorter
- located at the ends of the chromosomes
can genetic information consists outside of the cell
yes in some organelles like the chloroplasts and mitochondria carry genetic information
what is a gene
A gene is a segment of DNA that contains the instructions for the production of a specific protein or RNA molecule.
what is a mutation
A mutation when there is an error when DNA replication is occurring
where are the 3 checkpoints within the cell cycle
G1
G2
metaphase
what does the g1 checkpoint check
check to make sure the cell has grown enough, and makes sure the DNA is not damaged
what does the g2 checkpoint check
checks DNA has replicated properly and the cell size is of appropriate size
what does the metaphase checkpoint check
make sures the chromosomes are loaded onto the spindle fibres
what are the steps for meiosis
what are the stages of meiosis
Prophase I: Homologous chromosomes pair up and exchange segments of DNA in a process called crossing-over. This creates genetic diversity in the gametes.
Metaphase I: Homologous pairs of chromosomes align along the equator of the cell and spindle fibers attach to each chromosome.
Anaphase I: Homologous chromosomes separate and move to opposite poles of the cell.
Telophase I and cytokinesis: The cell divides into two daughter cells, each with one set of chromosomes (haploid).
Prophase II: The chromosomes condense again and a new spindle apparatus forms in each daughter cell.
Metaphase II: Chromosomes align along the equator of each daughter cell and spindle fibers attach to each chromosome.
Anaphase II: Sister chromatids separate and move to opposite poles of the cell.
Telophase II and cytokinesis: The cell divides again, resulting in four haploid daughter cells, each containing a single set of chromosomes.
what is an error in cell division called
aneupliody - where the number of chromosomes does not equal 46
what is a locus
the orientation of a gene on a chromosome
what are some factors that determine sex
environment
genetic
what is a genotype
describes the genetic constitution of an organism
what is a phenotype
describes the morphological, molecular and or behavioural properties of an organism resulting from a specific genotype and its interaction with the enviroment
what are mendel’s 3 laws for genetics
1.The Law of Segregation
2. The Law of Segregation
3. The Law of Dominance
what does The Law of Segregation state
Each individual has two copies of each gene, which segregate during gamete formation such that each gamete contains only one copy of each gene
what does the The Law of Segregation state
Genes for different traits are inherited independently of each other, meaning that the inheritance of one trait does not influence the inheritance of another.
what does the third law: law of dominance state
In a heterozygous individual (having two different alleles for a gene), the dominant allele is expressed, while the recessive allele is masked and does not produce a visible effect.
what is the formular for map distance
what is map distance
Map distance is the measure of the relative distance between two genes or genetic markers on a chromosome, which is determined by the frequency of recombination events between them during meiosis.
what is a dihybrid cross
A dihybrid cross is a genetic cross between two individuals that are both heterozygous for two different genes, resulting in the inheritance of two different traits.
what is an allele
Variants of genes that arise by mutation
what is incomplete dominace
Incomplete dominance is a type of inheritance pattern in which the phenotype of the heterozygous individual is an intermediate blend of the two homozygous parents, rather than one being completely dominant over the other.
- for example a red and white flower producing a pink flower
traits controlled by one gene are called
monogenic traits
traits that are controlled by multiple genes are called
polygenic traits
what do genes code for
proteins
what is the negative control for gene expression
Negative control, results in a decrease or turning off gene transcription
what is the positive control for gene expression
Positive control, results in the increase or turning on gene transcription
what is Constitutive gene expression
gene expression that is expressed under all conditions
what is regulated gene expression
Expressed only under certain conditions, most genes are required under certain conditions
what happens when there there is a low concentration of lactose
· Lactose is absent
· Lacl is expressed
· Lacl binds to lacO
· Lacl-lacO complex blocks RNA polymerase from binding
No expression from the lacZ, lacY and lacA genes
what happens when there is a high concentration of lactose
· Lactose is present
· Lacl is expressed
· Lactose (allolactose) binds to the lacl
· Lacl-allolactose complex is unable to bind to lacO
· RNA polymerase binds to lac promotor
Therefore RNA polymerase is able to transcribe the gene
what is disjunction
Disjunction normally occurs during the anaphase of mitosis and meiosis (I and II). During the anaphase of mitosis, sister chromatids separate and move towards opposite poles of the cell
- results in 2 sister chromatids in the same side of the cell=double chromosome
what is a hox gene
genes conserved from insects to animals
