Cell Cycle

interphase

interphase

-longest phase in the cell cycle -cells mature and perform normal functions (respiration/enzyme production) -consist of gap phase 1, synthesis phase, gap phase 2

gap phase 1

-hormonal growth/development -number of organelles and the amount of cytoplasm in a cell increase

synthesis

-DNA replicate -the chromosomes of a cell replicates

gap phase 2

-cell makes organelles and substances it needs for cell division -more mitochondria, puff cytoplasm, more golgi

homologous pair

-matching pair (size)

chromosome

-one pair from mom and one from dad -they do not come together, they replicate -double rods -dominant/recessive -biggest to smallest (pair 1 is biggest)

held together at centromere

where are chromosomes held together?

dominant

a gene in one strand of DNA that is stronger than the corresponding gene in another strand of DNA

recessive

a gene in one strand of DNA that is weaker than the corresponding gene in another strand of DNA

a sex chromosome

what chromosome are girls missing?

23

how many pairs of chromosomes do we have?

23 on lineup

what # is a sex chromosome on lineup?

mitosis

-the nucleus of a cell divides into 2 nuclei with identical genetic material -prophase, metephase, anaphase, telophase

cell division

-occurs in 2 main steps, the division of a cell into 2 daughter cells with the same genetic material -mitosis and cytokinesis

cytokinesis

cytoplasm of cell divides into 2 new cells (daughter cells)

prophase

-sister chromotad condense to become thicker -nucleolus/ nuclear envelope disappear -micro-tubules assemble

metaphase

-chromosomes are moved to center of cell by spindle fibers attached to centromeres

anaphase

centromeres of each chromosome are pulled by spindle fibers toward end of cell

telophase

new nuclei begins to form around chromosome mitosis is complete cell membrane begins to pinch cell in 2 as cytokinesis begins

shortened and condensed become visible

what happens to chromosomes in prophase

sister chromatin

identical copies formed by the DNA replication of a chromosome

cleavage furrow

where an animal cell pinches

cell plate

becomes the cell wall

asexual

1 parent

binary fission

-type of asexual reproduction -a parent cell divides, resulting in two identical cells, each having the potential to grow to the size of the original cell

sexual

2 parents

gamete

-pollen, sperm, egg -a reproductive cell of an animal or plant -not in asexual

sperm and pollen

male gametes

egg

female gamete

somatic cell

all cells in body except gametes have 2 complete sets of chromosomes

diploid

a cell like a somatic cell that has 2 complete set of chromosomes -2N

fertilization

combination of genetic material

zygote

result of fertilization and one celled organism

haploid

• single unpaired chromosomes -N -a cell like a gametes that has 1 complete set of chromosome

body cell

egg + sperm =

23 chromosomes

Human haploid

46 chromosomes

human diploid

23 chromsones

humans have how many chromosomes in gametes?

mutation

what occurs if sister chromotatids are not identical

not enough nutrients and oxygen

what happens if a cell is too big?

spindle fiber

made of microtubule fibers

germ cells

cells in the body that are specialized for sexual reproduction

2N

symbol for diploid

N

symbol for haploid

meiosis

a form of cell division in which the daughter cells that are produced have half the number of chromosones as the parent cell

meiosis 1 meiosis 2

what are the two parts of meiosis

meiosis 1

separates homologous pairs of chromosomes

meiosis 2

separates sister chromatid

the chromosomes shorten, condense visible nucelar envelope dissapears and homologous pairs come close to eachother and form tetrads

what happens in prophase 1

crossing over

homologous pairs may exchange through genetic material in a process called

the homologous pairs line up next to eachother and spindle attaches

what happens in metaphase 1

homologus pair seperates

what happens in anaphase 1

the cell begins to divide with only one part of each pair in a new cell

what happens in telophase 1

nuclear envelope begins to disappear again and we see the chromosomes

what happens in prophase 2

the chromosomes lineup in center of each cell

what happens in metaphase 2

the sister chromatid pull apart in each cell

what happens in anaphase 2

the 2 cells begin to divide

what happens in telophase 2

four haploid cells or gametes

cytokinesis during meiosis 2 results in?

an animal cell will have a cleavage furrow while a plant cell will have a cell plate

what is the difference in cytokinesis in a plant cell vs animal cell

no

are gametes identical

gamete

haploid relate to

body cell

diploid relate to

a diploid

what is a zygote

animal and plant cells

what type of cells does mitosis produce

gametes

what type of cells does meiosis produce?

homologous pairs

meiosis 1 deal with...

sister chromatin

meiosis 2 deals with..

tetrads

what forms in meiosis prophase 1

there is no crossing over event

Tetrads do not appear in mitosis because?

Meiosis is a process where a single cell divides twice to produce four cells(haploids) Mitosis is a process where a single cell divides into two identical daughter cells(diploids)

meisosis vs mitosis