Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

bio > lec 4 cell division > Flashcards

lec 4 cell division Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Why is cell divison nessecary?

A

-growth+development
-maintain+replace tissue
-pass genetic info

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are 2 broad stages of cell division? What happens?

A

Interphase: prepares cell for division
Mitosis OR miosis: cell divides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does mitosis occur?

A

cells that make up body but not involved in sexual reproduction

(ex skin cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where does miosis occur?

A

cells that sexually reproduce

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is mitosis? What must be replicated and passed onto the divided cells?

2 things

A

parent cell divides into 2 identical daughter cell

FIRST it replicates DNA+organelles, then divides

each daughter cell must have;
-full compliment of DNA from parent
-same organelles as parent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 3 major stages of interphase?

A

G1, S and G2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does each stage of interphase do? In order

A

G1: particular proteins made+activated for S phase

S (synthesis): DNA replicated

G2: makes proteins to prepare cell for mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which of our cells are actively dividing?

A

Skin and intestinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What phase do liver cells remain in?

A

G0 or resting phase for up to a year before undergoing division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a chromosome?

A

single strand of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does DNA fit in the nucleus? What is this called?

A

tightly wrapped around proteins

DNA+protien= chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When is the only time we can see chromosomes fully?

A

When DNA fully packed, during mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What must chromosomes do for mitosis to occur?

A

Replicate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How and when are chromosomes replicated?

how many phases

A

5 phases, before mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a chromatid? How are they joined?

A

each half of replicated chromosome

2 chromatids held together by centromere

(x shape, like chromosome, but a copy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the stages of mitosis?

A

Interphase, early prophase, late prophase, Anaphase, Telophase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What occurs in each stage of mitosis?

A

Interphase: DNA replicated

Early Prophase:
-first stage
-DNA condensed
-centrosomes move to opposite poles

Late prophase:
-nuclear envelope dissolves,
-spindle fibers attach to chromosomes

Anaphase:
-DNA segregation
-chromatids separated into single, daughter chromosomes by fibers
(chromatids–> new chromosomes)
(x shape ripped apart into 2 sticks)

Telophase: chromosomes arrive at spindle poles

Cytokenisis: cell divides

18
Q

Why are centrosomes important?

A

spindle fibers (microtubules) grow outwards from centrosomes

19
Q

What do spindle fibers do? where do they attach? where do they bring chromosomes?

A

attatch to each chromosome, and to each pole

-attatchment occurs at protein in centromere called kinetochore

-then, line up (single line, theyre on top of each other) chromosomes on metaphase plate (central equator of cell) during metaphase

20
Q

What occurs in telophase, detailed.

A

Last stage of mitosis

-spindle fibers break down
-chromosomes less condensed
-nuclei start forming

21
Q

What is the process called when cells PHYSICALLY divide, what forms?

A

Cytokinesis

in animal cells, cleave-furrow forms
-cell is pinched more and more until divided

22
Q

What is another name for mitosis?

A

Nuclear division

23
Q

What is the difference between mitosis in animals vs in plants?

A

same as mitosis, but cells dont pinch off

-vesicles carry cell wall components to central equator

-fuse together to create cell plate, then form cell wall

24
Q

what are pairs of chromosomes called? How many do we have and where do they come from?

A

homolouges

23 pairs,

23 individual chromosomes from each father and mother

25
Q

what are human gamates? what is important about gamates? how are they produced?

A

egg and sperm

gamates are HAPLOIDS, meaning they contain half of compliment of chromosomes

produced by MEIOSIS by diploid germ cells

26
Q

what do diploid germ cells have? what do they do?

A

diploid= contains full compliment of chromosomes

go thru meiosis to produce sperm (gamate) which is haploid

27
Q

what are haploids?

A

contain half of compliment of chromosomes

gamates are haploids

28
Q

what is it called when two haploids fuse?

A

fertilization

29
Q

what is a zygote?

A

result of fertilization

2 haploids=full compliment of DNA in zygote

30
Q

how are gamates made?

A

first, halving # of chromosomes

happens in meiosis 1

31
Q

what is meiosis 1 process of meiosis w/ respect to mitosis?

A

meiosis 1

same stages of mitosis, BUT each chromosome pairs with its homologue

32
Q

what is it called when a chromosome pairs w/ it’s homologue to form a pair?

A

bivalent pair

33
Q

function of each phase in meiosos

A

prophase 1: chromosomes pair

metaphase 1: spindle fibres attatch

anaphase 1: each bivalent pair seperated, not chromosomes ripped apart

telophase 1: nuclei with HALF the chromosomes

34
Q

what do spindle fibers do during meiosis

A

chromosomes line up in pairs

spindle from each side connects to ONLY the pairs on their side

35
Q

essentially, what is meiosis?

A

halving the chromosome number

36
Q

what are the resulting daughter cells of meiosis considered as?

A

haploid

37
Q

what happens after meiosis 1? what happens in anaphase 2?

A

meiosis 2: similar to mitosis

-haploid cells from meiosis 1 undergo second division

-chromatids seperate at anaphase 2

38
Q

what is the result of meiosis 2?

A

4 haploid cells (gamates) w/ HALF the chromosome number

  • NOW X shape into 2 peices
39
Q

in very simple terms, what is a big difference b/w mitosis and meiosis

A

mitosis: chromosomes seperated into chromatids

meiosis: chromosomes NOT seperated (2 FULL chromosomes paired up, then pairs seperated)

40
Q

very simply draw the dividing of chromosomes/pairs in mitosis and meiosis 1 and 2

A

MITOSIS
X —> I…….I
X —> I…….I
X —> I…….I
X —> I…….I

MEIOSIS 1
XX –> X ……….X
XX –> X ……….X

MEIOSIS 2
X ……X —> II……II
X …….X –> II……II

(dots are just spaces)

bio (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions