cell cycle , mitosis , meiosis

Question 1

—- the process by which cells copy their dna and divide to produce genetically identical daughter cells

Answer 1

cell cycle ( G0 , G1 , S , G2 )

Question 2

G0 is an — non-replicative phase and many differentiated cells remain in their such as —

Answer 2

• optional
• hepatocytes

Question 3

is a phase where cellular contents excluding the chromosomes duplicate , the preparation of cell division as well as the period of cell growth is —-

Answer 3

G1 phase ( 10 hours )

Question 4

true or false:
the G1 phase also includes replication of key components such as centrosomes

Answer 4

true

Question 5

The S phase in known as — where — occurs and it takes — where each of the 46 chromosomes id duplicated by the cell

Answer 5

• synthesis
• dna replication
• 5-6 hours

Question 6

a short resting phase as the cell double checks the duplicated chromosomes error and making any needed repairs before cell division which takes 3-5 hours is known as —

Answer 6

G2 phase

Question 7

humans have – chromosomes pair homologs which is — from autosomes and — from sex chromosomes . The sex determining chromosomes are — for females - and —- for male

Answer 7

• 23 ( 2n ) , 22 autosomes + sex chromosomes
• XX
• XY

Question 8

cell division is required for —– and to — new cells in adults

Answer 8

• development
• generate

Question 9

in somatic cells the division occurs in — during the cell cycle and it produces — cells aka — chromosesm

Answer 9

• mitosis
• diploid
• 2n , 2 copies of chromosomes

Question 10

— refers to the cell division and takes 2 hours

Answer 10

mitosis

Question 11

to generate gametes we need —- which is the specialised form of cell division and produces gametes ( sperm and eggs ) in — which is – copy

Answer 11

• meiosis
• haploid
• one copy , n

Question 12

true or false:
genomic dna must be copied accurately and divided between the daughter cells

Answer 12

true

Question 13

in — the dna is copied once so we have 46 chromosomes made of 2 chromatids held together by —- , they separate to form — chromosomes before divide once and become —-

Answer 13

• mitosis
• centromere
• 92 chromosomes
• 92/2 cells = 46 chromosomes which means = 2 x 23 diploid

Question 14

in G1, S , and G2 the —- is intact and — is not visible

Answer 14

• nuclear envelop
• chromosomes

Question 15

—- is a process when chromosomes are visible as the chromosomes consist of 2 sister chromatids , miotic spindle forms and nuclear membrane breaks

Answer 15

prophase

Question 16

sister chromatid line up at the centre during —-

Answer 16

metaphase

Question 17

sister chromatids are pulled apart and move to the opposite ends during —

Answer 17

anaphase

Question 18

spindle fiber break down , nuclear membrane forms , the chromosome begin to uncoil and forms chromatin

Answer 18

telophase

Question 19

the break down into 2 of cytoplasm and the cell divide is called —-

Answer 19

cytokineses

Question 20

— phase is when the nucleas break apart an attach to kinetochore

Answer 20

prometaohase

Question 21

the microtubule organising centre seeds outward growth of polar fiber is —

Answer 21

centresome

Question 22

—- is an essential dna sequence for the segregation of during cell division ( the lack of eccentric centromere don’t attach to the spindle , not passed to the daughter cells )

Answer 22

centromer I ( check slide 11 for the structure )

Question 23

— pattern of cell division that produces gametes aka germ cells ( eggs and sperm ) which are — and contain – copies of chromosome and the dna is copied —-

Answer 23

• meiosis
• haploid
• one copy
• once
  ( 46 chromosomes made of 2 chromatids held together in the centre of centromere ) so ,
  46/2 chromatids , 23/2 chromatid , 23/single chromatid = 92/4 = 23/cell haploid

Question 24

in meiosis the chromosomes condense as the nuclear envelop break and the crossing over ( aka exchanging segment ) occurs —

Answer 24

prophase 1

Question 25

when the chromosomes duplicate ---

Answer 25

interphase

Question 26

pairs of homologous chromosomes move to the centre and the microtubule is attached to the kinetochore in ---

Answer 26

metaphase 1

Question 27

homologous chromosomes move to the opposite poles as they split up in ----

Answer 27

anaphase 1

Question 28

the chromosomes gather at the pole and the cytoplasm divides , 2 haploid cells form and the chromosomes are still double in

Answer 28

telophase and cytokines

Question 29

- a new spindle forms around the chromosomes in ---- - the chromosomes line up the equator in ---- - centromeres divide and chromatid move to the opposite poles of the cells and sister chromatids separate in ---- - a new nuclear envelop forms and cytoplasm divides , haploid daughter cells forming

Answer 29

- prophase 2 - metaphase 2 - anaphase 2 - telophase 2

Question 30

true or false: during mitosis another round of cell division as the sister chromatid finally separates , 4 haploid cells form containing single chromosomes , division without replication

Answer 30

false , mieosis

Question 31

genetic diversity is generated in meiosis by 2 process -----

Answer 31

1-recombination ( pachytene in meiosis I ) 2- independent assortment

Question 32

--- refers to the physical breakage of dna duplex in one maternal and one paternal chromatids and joining of the end.

Answer 32

recombination

Question 33

in recombination the dna sequence is exchanged between --- but the dna sequence is ----

Answer 33

- chromatids - neither gained not lost unless a mistake as: non-disjuction = cytogenetics

Question 34

recmombination doesnt normally occur in ---- but once that happens the dna sequence is ------

Answer 34

- mitosis - gained or lost leading to bad results

Question 35

---- is when each bivalent is a 4 stranded structure ( 4 chromatids ) and the mitotic spindle pulls 2 chromatids towards each pole

Answer 35

independent assortment

Question 36

true or false: for humans 2 power 23 = 8.4 x 10 power 6 possible combination

Answer 36

true , check slide 16 + 17

Question 37

--- identical copy of maternal and paternal homolog --- mixed copy of maternal or paternal homolog

Answer 37

- diploid - haploid

Question 38

1-mitotic tetrads with --- chiasmata 2- each chiasmata marks a ---- 3- on average --- chismata/cell in human make meiosis up to --- more in females

Answer 38

- 2 - crossing over point - 55 - 50%

Question 39

--- is important for correct chromosome segregation at meiosis I , holds the homologs together until align along plate and formation of spindle until ----- . Children w/ incorrect chromosomes number often the product of gametes where bivalent lacked ---- . These crossovers may involve --- or --- in a bivalent

Answer 39

- chiasmata - anaphase I - crossover - 3 or even all chromatids

Question 40

1-haploid gametes arise by --- from a ----- 2- in fertilization an egg and sperm chromosomes combine forming ---- , further round of ---- and ---- to form a whole organism

Answer 40

- meiosis - diploid precursor - diploid zygot - mitosis and differentiation

Question 41

the -------- develops by repeated mitotic divisions of diploid cells leading to the production of ------ and ----- which then undergo ----

Answer 41

- germ-line - primary oocytes and primary spermocytes - meiosis

Question 42

in ovary the priamry oocytes form in ---- but arrest at --- of the ----- until puberty

Answer 42

- fatal life - prophase of mieosis 1

Question 43

true or false: before puberty one oocyte/month completes meiosis true or false: sperm produced continuously from puberty

Answer 43

1- false: after puberty 2- true

Question 44

most cells are --- which means 2 homologs pairs of each chromosomes one --- and one --- so 2 copies of each gene per ---- copy

Answer 44

- diplpoid - paternal and one maternal - per one chromosome copy

Question 45

each gene copy is called an ---- as they can slightly vary in their dna sequence so, a person can have a different allele of a --- as A , a

Answer 45

- allel - gene

Question 46

---- is when a populations of genes have many alleles

Answer 46

polymorphism

Question 47

different alleles combine to form ----

Answer 47

different genotype ( genetic constitution )

Question 48

read:

Answer 48

Human inherited diseases Caused by genetic (ie: DNA) defects disease genotype --- > disease phenotype Two broad categories: 1. Single-gene (monogenic) defects Single disease allele, dominant or recessive Simple Mendelian inheritance pattern Autosomal dominant Autosomal recessive X - linked dominant X - linked recessive Identified in families by ‘Pedigree Analysis’ 2. Multi-gene (polygenic) defects Interactions of several genes Complex (ie: non-Mendelian) inheritance