CHAPTER 5: CELL DIVISION

CELL DIVISION INCREASES THE NUMBER OF BLANK CELLS (BODY CELLS)

SOMATIC

CELL DIVISION IS PART OF THE BLANK CYCLE

CELL

ORDERLY SET OF STAGES THAT OCCUR BETWEEN THE TIME A CELL DIVIDES AND THE TIME THE RESULTING DAUGHTER CELLS DIVIDE, IS KNOWN AS BLANK BLANK

CELL CYCLE

STAGES IN ORDER FOR THE CELL CYCLE

G1 S G2 M

G1(BLANK PHASE 1): NEW ORGANELLES ARE PRODUCED TO BLANK THOSE LOST TO THE OTHER CELL

GROWTH. REPLACE

S: CHROMOSOMES ARE BLANK (NEW DNA IS BLANK)

DUPLICATED. SYNTHESIZED

G2(GROWTH PHASE 2): CELL PREPARES FOR BLANK BY PRODUCING BLANK

DIVISION. PROTEINS

M STAGE: NUCLEUS AND CYTOPLASM DIVIDE (BLANK AND BLANK)

MITOSIS. CYTOKINESIS

THERE ARE BLANK REGULATORY CHECK POINTS THE CELL MUST MOVE THROUGH FOR CELL DIVISION TO OCCUR, OTHERWISE DIVISION BLANK

THREE. STOPS

G1-CELL DETERMINES IF DNA IS READY TO BE BLANK

DUPLICATED

G2- CELL DETERMINES IF DNA DUPLICATION WAS BLANK

SUCCESSFUL

M- THE CELL CYCLE STOPS WHEN BLANK ARE NOT BEING DISTRIBUTED TO NEW CELLS

CHROMOSOMES

AN INDIVIDUAL MOLECULE OF BLANK IS A CHROMOSOME

DNA

CHROMOSOMES THAT ARE THE SAME SIZE, SHAPE, AND CARRY SIMILAR GENES IS KNOWN AS BLANK BLANK

HOMOLOGOUS CHROMOSOMES

CELLS THAT HAVE TWO (A PAIR) OF EACH TYPE OF CHROMOSOME (2 OF EACH HOMOLOGOUS CHROMOSOME). ONE CHROMOSOME COMES FROM THE FATHER THROUGH THE SPERM, THE OTHER COMES FROM THE MOTHER THROUGH THE EGG. THIS IS KNOWN AS BLANK (BLANK) BLANK

DIPLOID 2N CELLS

HUMANS HAVE A DIPLOID NUMBER OF BLANK (FOUND IN BLANK BODY CELLS)

46. TYPICAL

CELLS THAT HAVE HALF THE DIPLOID NUMBER CHROMOSOMES (ONE OF EACH TYPE OF CHROMOSOME)(ONE O EACH HOMOLOGOUS CHROMOSOME). THIS IS KNOWN AS BLANK (BLANK) BLANK

HAPLOID 1N CELLS

HUMANS HAVE A HAPLOID NUMBER OF BLANK (FOUND IN BLANK AND BLANK)

23. SPERM. EGG

IN MITOSIS THE NUCLEAR DIVISION IN WHICH THE CHROMOSOME NUMBER STAYS BLANK

CONSTANT

DNA REPLICATION DURING MITOSIS PRODUCES BLANK CHROMOSOMES

DUPLICATED

EACH DUPLICATED CHROMOSOME IN MITOSIS IS COMPOSED OF BLANK SISTER CHROMATIDS HELD TOGETHER BY A BLANK

2. CENTROMERE

IN MITOSIS THE SISTER CHROMATIDS ARE GENETICALLY BLANK

IDENTICAL

DURING MITOSIS, THE CENTROMERE DIVIDES AND ONE OF EACH SITER CHROMATID IS SENT TO EACH NEW CELL AS A BLANK CELL

DAUGHTER

EACH NEW CELL IN MITOSIS RECIEVES A BLANK CELL AND GETS ALL OF THE GENTIC MATERIAL IT NEEDS TO FUNCTION

NEW

A TYPE OF DIVISION OF THE NUCLEUS THAT PRODUCES DAUGHTER CELLS THAT HAVE THE SAME NUMBER AND KINDS OF CHROMOSOMES AS THE ORIGINAL BLANK CELL, THIS IS KNOWN AS BLANK

MOTHER. MITOSIS

OCCURS THROUGHOUT THE BODY TO REPLACE CELLS THAT HAVE DIED OR TO MAKE NEW CELLS FOR GROWTH IS KNOWN AS

MITOSIS

THE 4 CONTINOUS STAGES OF MITOSIS IS

PROPHASE METAPHASE ANAPHASE TELOPHASE

NUCLEAR MEMBRANE DISAPPEARS, CENTROSOMES MIGRATE AWAY FROM EACH OTHER, SPINDLE FIBERS APPEAR, CHROMOSOMES THICKEN

PROPHASE

CHROMOSOMES LINE UP AT THE MIDDLE (FORMING A PLATE) OF THE CELL

METAPHASE

CENTROSOMES DIVIDE, SISTER CHROMATIDS MIGRATE TO OPPOSITE POLES

ANAPHASE

NUCLEAR MEMBRANE FORMS, SPINDLE DISAPPEARS, CHROMOSOMES UNWIND, CYTOKINESIS OCCURS

TELOPHASE

HOW PLANT CELLS DIVIDE:
-OCCURS IN BLANK TISSUES
-SAME PHASES AS BLANK CELLS
-PLANT CELLS DO NOT HAVE BLANK OR BLANK

MERISTEMATIC. ANIMAL. CENTRIOLES. ASTERS

CYTOKINESIS IN ANIMAL CELLS:
-BLANK FURROW FORMS BETWEEN DAUGHTER NUCLEI AND DIVIDES FROM THE OUTSIDE INWARD
-BLANK RING CONTRACTS DEEPINING THE FURROW
-CONTINUES UNTIL BLANK IS COMPLETE

CLEAVAGE. CONTRACTILE. SEPERATION

CYTOKINESIS IN PLANT CELLS:
-CELL PLATE FORMS ON THE BLANK BETWEEN DAUGHTER CELLS
-BLANK APPARATUS PRODUCES VESICLE WHICH MOVE TO DISK AND FORM PLASMA MEMBRANE
-RELEASE BLANK WHICH BUILD NEW CELL WALLS

INSIDE. GOLGI. MOLECULES

A REPRODUCTIVE CELL (IS HAPLOID)

GAMETE

A MALE GAMETE

SPERM CELL

A FEMALE GAMETE

EGG CELL

THE CELL FORMED BY THE UNION OF TWO GAMETES (IS DIPLOID)

ZYGOTE

Meiosis a type of division that:
Occurs in the life cycle of blank reproducing organisms to produce gametes (sperm or egg)
Serves to keep the chromosome number blank from generation to generation by reducing the chromosome number from the diploid number t

sexually
constant
increase

Overview of Meiosis
involves 2 nuclear divisions (meiosis I and meiosis II) and produces blank haploid daughter cells
Cells are blank at beginning of meiosis
Pairs of chromosomes are called blank. One comes from that individual's father and the other from

4
diploid
homologues
daughter

Meiosis I
Homologues line up side by side at equator (blank)
When pairs blank, each daughter cell receives one member of the pair
Cells are blank at the end of meiosis I

synapsis
seperate
haploid

period of times between meiosis 1 and meiosis 2, no duplication of the chromosomes occur because they have already been duplicated before meiosis 1

interkenesis

Meiosis II
No replication of blank occurs in this division
Centromeres divide and sister chromatids migrate to blank poles to become individual chromosomes
Each of the blank daughter cells produced has the haploid chromosome number and each chromosome is

dna
opposite
4
haploid

restores the diploid number of chromosomes in a cell (zygote) that will develop into a new individual

fertilization

Genetic variation helps populations adapt to the environment and is generated three ways
blank blank
Independent Assortment of blank Chromosomes
blank

crossing over
Homologous
fertilization

Crossing Over
-it happens during meiosis I, the 2 homologous chromosomes bond to each other by a process called blank
-the genetic material of two blank chromatids is exchanged between homologous chromosomes while they are aligned (crossing over).
-it is

synapsis
nonsister
new

DNA replication occurs only blank prior to either meiosis and mitosis
Meiosis requires blank nuclear divisions, mitosis only one
Meiosis produces blank daughter cells, mitosis produces two
Daughter cells from meiosis are blank, those from mitosis are dipl

once
two
four
haploid
variable

Recognize the difference between spermatogenesis and oogenesis
both require blank and blank
Meiosis in the female is called blank
Meiosis in the male is called blank
At fertilization, the resulting blank divides by mitosis for the processes of growth and

meiosis. mitosis
oogenesis
spermatogenesis
zygote
repair