Genetics: Chapter 1.2 Genome and Genetic Variation

genome

the complete set of genetic information for an organism

the human genome

the 23 pairs of chromosomes and all the genetic material contained therein

all the genes (and their alleles) present in an organism and other DNA sequences that do not encode genes (make a protein)

what is included in the genome?

1.5%

only ___% of the DNA in the human genome encode protein (of about 24,000)

noncoding DNA

highly repeated sequences with unknown functions in DNA

proteomics

area of science that looks at the expression of that 1.5% of DNA that encodes protein

proteomics

allows us to look at the expression of what specific enzymes and proteins are expressed within cells and then understand what specific cells create, used to understand cancer. Looks at the 3D structure and expression.

1.5%

protein-coding genes make up ___% of the genome

variation

produced by mutation and “shuffled” by recombination

evolution

variation is important for…

polymorphisms

variations in the DNA sequence in individuals or groups that occur in at least 1% of the population; can be 1 to 1000’s of bases; may or may not have an effect

single nucleotide polymorphisms (SNPs)

single base sites that differ among individuals and are important as markers

substitution, deletion, addition

3 types of mutations

substitution

type of mutation where one pair is replaced by another

deletion

type of mutation where one pair is deleted from the sequence

addition

type of mutation where one pair is added to the sequence

gametes

a mutation is only passed on during reproduction if it happens to the _____

crossing over

creates new combination of genes; occurs between two homologous chromosomes

atom → molecule → macromolecule → organelle → cell → tissue → organ → organ system → organism

type out the levels of organization within the body from atoms to organism

same

all cells with a nucleus in the body contain the _____ (same/different) genetic information

stem cells

type of cell that are less specialized and can become many different cell types

differentiation

______ causes ells to differ in appearance and function

variation in gene expression

differentiation is controlled by…

toti-potent stem cells

very early in development; involved in the placenta and the creation of the other types of stem cells

pluri-potent stem cells

can be converted into just about any cell in the body

endoderm line

type of cell that becomes lung and pancreas cells

mesoderm line

type of cell that becomes heart muscle and red blood cells

ectoderm line

type of cell that becomes skin and neurons

multi-potent stem cells

stem cells that break off into three different lines (an endoderm line, mesoderm line, or an ectoderm line)

genotype

the unique combination of alleles they carry

phenotype

visible trait

dominant alleles

alleles expressed if the individual carriers one or two copies of the allele

recessive alleles

the alleles only expressed if the individual carries two copies of the allele

pedigree

indicates the structure of a family schematically

population

a group of interbreeding individuals

gene pool

the total of all the alleles in a population

evolution

the changing allelic frequencies in populations over time

mendelian traits

traits that are determined by a single gene pair

multifactorial traits

traits that are not controlled by a singe gene

multifactorial

are most traits mendelian or multifactorial?

gene; environment

multifactorial traits are influenced by more than one ____ and the _______

True

True or False: some illnesses may occur in different forms such as mendelian, multifactorial, and non-inherited

simple inheritance

mendelian traits are also called…

ok

BRCA1 gene can make you more susceptable to cancer, but it isn’t the sole determining factor. There are other environmental factors that play into it. Example of multifactorial traits.

mendelian inheritance

refers to the inheritance of traits controlled by a single gene with two alleles, one of which may be dominant to the other (example is whether you have attached earlobes or free-hanging earlobes)

genetics + environment + lifestyle

How multifactorial traits allow disease to occur