meiosis

Question 1

who does meiosis

Answer 1

All Multicellular Eukaryotes: Animals, Plants, Fungi, some algae

Question 2

Why is meiosis done

Answer 2

for sexual reproduction

Question 3

why is sexual reproduction for meiosis important

Answer 3

because It allows genetic recombination
New combinations of genes may ..
a. better suit environments
b. allow offspring to survive radical environmental change
c. allow offspring to survive a disease outbreak

Question 4

cells produced by meiosis are called

Answer 4

gametes

Question 5

sex chromosomes

Answer 5

determine sex (in humans XX = female, Xy = male)

Question 6

autosomes

Answer 6

any chromosome not used to determine sex of offspring

Question 7

gametes

Answer 7

haploid cells made by meiosis

Question 8

haploid cells

Answer 8

have one set of chromosomes
called 1n cells
mathematical representation

Question 9

n=

Answer 9

number of different C types

Question 10

diploid

Answer 10

cells have two of each kind of chromosome

2n

Question 11

where does meiosis happen

Answer 11

only in gonads

Question 12

gonads

Answer 12

reproductive organs ; testis and ovary

Question 13

specialized cells in gonad do

Answer 13

meiosis

spermatocytes and oocytes

Question 14

Spermatocytes and oocytes are constantly replaced by

Answer 14

specialized Spermatogonia cells & oogonia cells

Question 15

Spermatogonia cells do Mitosis make

Answer 15

one primary spermatocyte and a cells that stays a spermatogonia

Question 16

what does the primary spermatocyte do

Answer 16

does meiosis to make four spermatids

Question 17

sperm diagram

Answer 17

acrosome- vesicle w/ penetratin enzymes
nucleus- 1n
midpiece- makes ATP and powers flagellum (filled w/mitochondria)
tail- flagellum

Question 18

oogenesis

Answer 18

Oogonia do
Mitosis to make
1 primary Oocyte

Question 19

primary oocyte does what

Answer 19

meiosis one to make one secondary oocyte and one polar body
Meiosis II ( after fertilization) makes
1 ovum &1 polar body

Question 20

meiosis one main purpose

Answer 20

separate homologous pairs (cells become 1n with X shape C)

Question 21

prophase one

Answer 21

Nuclear envelope breaks down, spindle forms, condense chromatids
synapsis, crossing over, chiasmata

Question 22

metaphase one

Answer 22

chromosomes line up in pairs

Question 23

anaphase one

Answer 23

Homologs move to
opposite poles
(cohesin along arms breaks down)
(cohesin at centromeres remains)

Question 24

telophase one

Answer 24

Cytokinesis simultaneously
X shaped C reach poles
Many cells do not decondense C or 
reform nuclear E
Spindle only partly broken down

Question 25

homologous chromosomes

Answer 25

same C type same length code for same gene (but different versions)

Question 26

what are the only pair of Homologues that do not look alike

Answer 26

X and Y sex chromosomes

Question 27

synpasis

Answer 27

Homologous Chromosomes pair up Line up gene to gene then physically connect along their arms Proteins form a synaptonemal complex that bind them together

Question 28

crossing over

Answer 28

Non-sister chromosomes trade corresponding segments of DNA

Question 29

which genes cross over most

Answer 29

genes farthest from centromere

Question 30

the gene’s locus (loci)

Answer 30

location of a gene on a chromosome

Question 31

distance from centromere measured in

Answer 31

map units

Question 32

chiasmata

Answer 32

X shaped region where crossing over has happened. Synaptonemal complex has broken down but … Cohesions still hold sister chromatids together

Question 33

Meiosis in Fungi

Answer 33

Fungal bodies formed of hyphae

Question 34

what is hyphae

Answer 34

filaments made of chains of 1n cells for fungal bodies

Question 35

what forms the fungal body and what is it called

Answer 35

Hyphae interweave to form fungus body | The body mass is called a mycelium

Question 36

if hypha + and - meet...

Answer 36

the two cells fuse cytoplasm and nuceli and then do meiosis to make 4 haploid nuclei, then do mitosis to form 8 nuceli

Question 37

plasmogamy

Answer 37

fusing two cells cytoplasm

Question 38

karyogamy

Answer 38

fusing nuclei of two cells (2n)

Question 39

what happens to the 8 nuclei formed from the hypha meeting

Answer 39

Each nucleus grows a tough casing around it and becomes a Spore spores disperse on the wind and germinate to make new 1n hyphae

Question 40

ascus

Answer 40

The ascospores that form from one cell stay together in a capsule called an ascus

Question 41

crossing over pattern and non crossing over pattern

Answer 41

no crossing over is 4:4 any other patterns results from crossing over

Question 42

genetic variation increased by

Answer 42

crossing over and independent assortment

Question 43

what is independent assortment

Answer 43

Each pair of homologues lines up randomly and Independent of how other pairs line up

Question 44

2^n

Answer 44

different gametes formed = 2^n example Humans = 2^23 or 8,399,608

Question 45

Where does the spindle and envelop reform and dependence chromatids?

Answer 45

Telophase 2

Question 46

Meiosis one is for | Meiosis two is for

Answer 46

Meiosis one- separate homologous chromosomes 2n-1n end up haploid Meiosis 2- separate sister chromatids