Genetics Unit 1

describe the key features of prokaryotic cells

single circular chromosome

ribosomes

nucleoid

plasma membrane

cell wall

flagellum

describe the key features oe eukaryotic cells

DNA condensed into chromosomes

membrane bound organelles

membrane bound nucelus containing

what are the primary similarities between prokaryotes and eukaryotes

ribosomes from protein synthesis

plasma membrane

what are the two types of animal cells

somatic cells and germ cells

what are somatic cells

cells that make everything in the body except reproduction

what are germ cells

sperm and egg cells

what are chromosomes?

a structure composed of DNA and proteins

what is the DNA protein-complex called in eukaryotes

chromatin

what is a centromere

attachment point for spindle fibers

what are cohesions?

proteins that hold sister chromatids together

what are telomeres?

protective caps of extra genetic material

what are kinetochores?

protein structures that sit at the centromere and connect chromosomes to spindle fibers

what is a single chromatid?

a single linear DNA molecules that contains a single copy of a gene

what is the relationship between sister chromatids

two identical copies of a chromosome connected at the centromere

have the same genes and the same alleles of that gene

what is the relationship between homologous chromosomes?

the same gene but possibly different alleles

aligned but not connected at the centromere

what is a locus

the physical location of the gene on the chromosome

how many total chromosomes are in a typical diploid human cell

46

how many sets of homologous chromosomes are in a typical diploid human cell

23

why are sister chromatids identical

they are replications of each other

what are homologous chromosomes different from each other

you get one set from each parent during fertilization

what is binary fission

the means of reproduction for bacteria and yeast

what are the steps in order of binary fission

1. replication of bacterial chromosome

2. z-ring forms between the chromosomes

3. septum forms

4. two daughter cells are separated

what created the z-ring in binary fission

Fts-z fillaments

are the daughter cells of binary fission identical or different?

identical

what are the phases of the eukaryotic cell cycle?

interphase, mitosis and cytokinesis

what are the phases of interphase

G0, G1, S, and G2

what happens during G0 phase

cells normal function and the majority of the cells life

what happens during G1 phase

the cell grows in size and prepares to divide

what happens during the S phase

the chromosome is replicated

how many pairs of chromatids are present in the cel during S phase

92 distinct chromosomes, 46 pairs

what happens during the G2 phase

the cell accumulates organelles, proteins and enzymes

what are the phases of mitosis

prophase

prometaphase

metaphase

anaphase

telophase

cytokinesis

what occurs during prophase

nuclear envelope begins to degrade

cohesions stick sister chromatids together

what occurs during prometaphase?

nuclear envelope entirely disappears

spindle fibers attach to chromosomes

what happens during metaphase?

the chromosomes are lined up along the metaphase plate

M-checkpoint

breaking down of cohesians

what is the m-checkpoint looking for?

aligned chromosomes

spindle fibers attached

what is the result of a cell passing the m-checkpoint?

securin and separate bind to one another and break the cohesian bonds between sister chromatids

what happens during anaphase?

spindle fibers shorter back to the asters pulling apart the sister chromatids

what happens during telophase

nuclear envelopes reform around the two groups of chromosomes

cleavage furrow forms

what happens during cytokinesis

the two daughter cells are fully separated

what is the final result of mitosis

two identical daughter cells with the same set of chromosomes as the parent cell

what is meiosis?

the process of forming reproductive cells

what is the primary different between meiosis and mitosis>

the replication process occurs twice in meiosis and produces four cells which half the number of chromosomes as the parent

mitosis replicates one and produces two cells with the same number of chromosomes as the parent

what are the phases of meiosis 1 and 2

prophase 1

pro metaphase 1

metaphase 1

anaphase 1

telophase 1

cytokinesis

what happens during prophase 1 of meiosis?

chromosomes condense

synapsis, homogenous chromosomes pair together