Bio 001 Exam 3

ONE chromosome (circular) and not wound around protiens, NO organelles, ALL single celled organisms

MULTIPLE chromosomes (linear) and wrapped around protiens, chromosome in NUCLEUS, single celled OR multicellular organisms

Reproduction (ALL organisms), growth and repair (ONLY multicellular eukaryotes)

ONE parent produces genetically identical offspring (same DNA sequence as parent)

fusion of egg and sperm (gametes), genetically unique offspring

2 genetically identical offspring: 1. DNA replication starts 2. Chromosome copies are pulled to opposite sides of dividing cell 3. Cell splits (physically divides)

ALL chromosomes in a cell: ALL cells of a multicellular organisms have the same sets of genes, different chromosomes have different sets of genes

position of gene on a chromosome

ONE set of chromosomes; gametes (egg or sperm), cells of some eukaryotes (eg fungi, mosses)

TWO sets of chromosomes, 2 alleles for every gene; single cell eukaryotes and body cells of multicellular organisms

a pair of chromosomes with the same sets of genes, seperated in meiosis but NOT mitosis

different versions of the same gene

cell has the same number of different chromosomes, but TWICE as much DNA

duplicate copies of an individual chromosome, generated by DNA replication (ONLY exist in pairs)

chromatids of homologous chromosome pair that are NOT sisters (one from each of the homologous chromosomes), alleles can be the same of different (1 copy of each of the 2 homologous chromosomes)

2 genetically identical daughter cells, parent cell can be haploid or diploid; purpose- growth and repair of multicellular organisms, asexual reprodiction

4 genetically different haplod daughter cells, MUST be diploid parent cell; purpose- formation of eggs and sperm for sexual reproduction

allows chromosomes to be distributed; sister chromatids stay attached, allows them to be distributed to different daughter cells; mitotic spindle forms- fibers exten from each ond of the cell

spindle fibers attach to chromosomes- sister chromatids attach to fibers from opposite sies of the cell so sister chromatids distributed to different daughter cells

line up chromosomes

seperated, transported by spindle fibers

forms around chromosomes at each end

cell pinched into 2 seperate cells by ring of fibers

uncontrollable cell division due to mutations in genes that contain information for protiens that promote or prevent cell division; mutations in body cell CANNOT be passed to next generation; mutations in gametes CAN be passed to next generation - offspring have increased risk but need additional mutations to arise

go from 2 sets of chromosomes (diploid) to one set of chromosomes (haploid)

done before meiosis I

chromosomes condense, spindle forms, nuclear memebrane breaks down

homologous chromosomes swap pieces of DNA, CAN occur

from opposite sides, get attached to one of each of homologous chromosomes

pairs linf up in middle of cell - each pair up independently of other pairs

pulled by spindle fibers to opposite sides of cell

generates 2 cells - haploid that have replicated chromosomes

similar to mitosis, 4 genetically unique haplod cells from sister chromatids seperately

DIFFERENCES IN ALLELES of homologous chromosomes, INDEPENDENT ORIENTATION of homologous chromosomes in meiosis I, CROSSING OVER in meiosis II

study of how traits if individual are passed from parent to offspring

differences in the information (DNA) required to create and matinain cells

physical or functional feature that can be inherited (influenced by genes) - like genes

variants of a character - like allele

combination of alleles

combination of traits (physical or functional)

generates different allele combos for genes of DIFFERENT chromosomes, how one pair of homologous chromosomes line up does NOT affect other pairs

can generate different allele combos on the SAME chromosome, paired up homologous chromosomes can swap corresponding pieces of DNA (trade pieces with the same genes)

which specific egg is fertilized, patterns of inheritence (mendels laws)

many traits follow specific patterns of inheritence

traits are primarily determinded by genes, genes are located on chromosomes, passing of chromosomes from one generation to the next helps explain patterns of inheritance

some organisms have chromosomes that differ between sexes

inheritence patterns of some traits are directly linked to organisms sex

genes located on chromosomes common to males and females (autosomes); mendelian and nonmendelian traits

determined by ONE autosomal gene with only 2 different alleles, one trait dominates the other when 2 different alleles are present

genes located on sex chromosome (have genes that determine sex)

SAME alleles for a gene

DIFFERENT alleles for a gene

combos of alleles from egg and sperm

determine probability of any offspring (independent from eachother)

LARGE sample sizes closer to true probabilities

of homologous chromosomes is why different allele combos are possible for genes on different chromsomes

an organism chosen to study specific biological phenomenon due to beneficial features: inexpensive and easy to grow, many different varieties with easily distinguishable traits for various characters, matings can be controlled, short reproductive time, produce lots of offspring

eggs fertilized by sperm from SAME plant

produces eggs that can be fertilized by sperm from pollen

produces polled that contains sperm

ALL offspring of self fertilization always have the same traits as parent (a particular trait, not all traits), ALWAYS HOMOZYGOUS

a controlled mating between 2 individuals

analyze inheritenence between ONE character

analyze inheritence in TWO characters

phenotype observed for heterozygotes (NOT more common of beneficial)

allele that corresponds to a dominant trait (NOT more common of beneficial)

individual MUST have TWO alleles that correspond to the recessive trait to show the trait

allele that corresponds to the recessive trait

one allele completely masks the other (look at particular trait)

FOUR different gamete genotypes, independent orientation results in all possible combos of alleles

TWO different gamete genotypes; If no crossing over between the genes, alleles on the same chromosome will stay "packaged" together

female

male

genes on the X chromosome

genes on the Y chromosome

nucleus of cell from male that forms sperm

nucleus of cell from female that forms egg

during development, one X chromsome is inactivated in each cell (random process)

most genes have more than 2 possible alleles

heterozygotes have intermediate phenotype

heterozygotes show both traits

a character is determined by more than one gene, often show new F2 phenotypes or a continuum of phenotypes

one gene affects more than one character, effects on different characters can be related or have no apparent connecion

limited understanding of disease phenotypes

must be homozygous for disease allele to be affected, heterozygous carriers (have disease allele but not the disease), heterozygotes are partially affect in some diseases (eg alleles show incomplete dominance)

only need ONE copy of the disease allele to be affected, homozygous dominant and heterozygous are equally affected

females must be homozygous for the disease allele to be affected, ALL males with disease allele are affected