AP Biology Mitosis and Meiosis Quiz Review

genome definition

the complete set of DNA instructions for an organism

daughter cells

the resulting cells of mitosis

chromosomes

how DNA is packaged in a cell to prepare for cell division

chromatin

when the DNA is not packaged into chromosomes

histones

proteins that DNA wraps around

somatic cells

cells that have a full set of chromosomes

• diploid

• 2N

• 46 chromosomes in humans

• made through mitosis

replication

copies of DNA are made

• occurs during S phase of interphase

• in the neucleus

sister chromatids

either side (2 identical copies) of a single replicated or duliplicated chromosome

cell cycle

a highly regulated series of events for the growth and reproduction of cells

interphase

growth and preparation

mitosis

division of the neucleus

cytokenesis

division of the cytoplasm

mitotic spindle fiber

• made up of microtubes

• orginiate from centrosomes

• attach to kinetochores on either side of centromere

what is the end result of mitosis

2 identical daughter cells

cytokinesis in animal cells

cleavage furrow

definition of cleavage furrow

pinching off of the cytoplasm to seperate animal cells

cytokinesis in plant cells

cell plate

G0

a resting phase where a cell is not dividing or preparing to divide

how is the cell cycle regulated

internal controls or checkpoints regulate progression through the cell cycle

M-spindle

checks for spindle attachment to chromosome

• between metaphase and anaphase

• MPF allows cell to proceed past checkpoint

G1

At the end of g1, after s phase

• checks for cell size, nutrients, growth factors, dna damage

G2

at the end of g2, before mitosis

• checks for dna damage and dna replication

cyclins

a group of related proteins associated with specific phases of the cycle

cyclin dependent kinases

a group of enzymes involved in cell regulation 

• requires cylin binding for activation

• MPF (mitosis premoting factor)

MPF

triggers the cell’s passage past the g2 checkpoint into mitosis

• is a CDK with M cylin activating it

density-dependent inhibition

crowded cells stop dividing

• cells will stop going through the cell cycle when they have reached a certain density

anchorage dependence

cells must be attached to a substration (solid surface) to survive, grow, and divide

cancer cells

exhibit neither density dependent inhibition nor anchorage

• checkpoints in the cells are not functional

when cells begin to divide the organism has

cancer

if a caner does not grow larger

benign

abnormal cancer cells tend to pile up on each other to form a

tumor

apoptosis

programmed cell death

what is meiosis

ensures the formation of haploid gamete cells in sexually reproducing diploid organisms

outcomes of meiosis

results in daughter cells with half the number of chromosomes as the parent cells

• ensures genetic diversity in sexually reproducing organisms

gene

a portion of DNA that codes for a specific protein on a chromosome

locus

location of a gene on a chromosome

zygote

when gametes, sperm and egg, fuse to form a diploid cell

• will go through mitosis to develop into an adult organism

autosomes

carry the same characteristics in males and females

sex chromosomes

different from each other in their characteristics. are represented as X and Y. 

• 2 in humans 

• determine the biological sex of an individual

• XX is female XY is male

homologous chromosomes

a pair of autosomes

tetrad

mom + dad’s chromosomes (duplicated)

meiosis ensures that

each gamete recieves one complete haploid (N) set of chromosomes

meiosis 2 does not go through

interphase

what are the 3 ways meiosis produces genetic variation

1. independent assortment

2. crossing over

3. random fertilization

independent assortment

homologous pairs of chromosomes arrange/orient themselves randomly when they line up in M1

• either chromosome can go to either side

crossing over

homologous chromsomes physically connect and exchange genetic information

random fertilization

the fusion of gametes 

• any sperm can fertilize any egg

• provides combinations of genetic information in the zygote