Cell Division for Development, Growth, and Maintenance in Multicellular Organisms (Mitosis) Flashcards Preview

DISP Biology > Cell Division for Development, Growth, and Maintenance in Multicellular Organisms (Mitosis) > Flashcards

Flashcards in Cell Division for Development, Growth, and Maintenance in Multicellular Organisms (Mitosis) Deck (53)
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1
Q

What are three main reasons for which cells need to divide?

A

reproduction, development (including growth), maintenance

2
Q

What does maintentance involve?

A

repairing damage, tissue renewal…

3
Q

What is growth?

A

increase in number of cells

4
Q

What are ways cells develop other than growth?

A

differentiation, morphogenesis…

5
Q

What is the difference between stem cells and most other cells?

A

most cells differentiate while stem cells don’t

6
Q

What happens when a cell differentiates?

A

becomes specialized, develops into a certain type of cell

7
Q

What makes a cell lose the ability to become other kinds of cells?

A

differentiation

8
Q

What cells remain plastic?

A

stem cells

9
Q

What does “plastic” mean in terms of cells?

A

ability to generate different types of cells

10
Q

What are two special characteristics of stem cells?

A

self-renewal and potency

11
Q

What does self-renewal mean?

A

cells continue to divide and divide without differentiating

12
Q

What is potency?

A

capacity to produce cells that differentiate into specific cell types

13
Q

What is an extreme case of tissue renewal?

A

limb regeneration in animals

14
Q

What are some animals that can regenerate their limbs?

A

starfish, crabs, salamanders

15
Q

What are the 4 types of stem cells?

A
  • totipotent
  • pluripotent
  • multipotent
  • unipotent
16
Q

What types of cells can totipotent stem cells form?

A

any cell in the body

17
Q

What type of stem cell can only form one type of tissue?

A

unipotent

18
Q

What can pluripotent stem cells form?

A

most types of tissues

19
Q

What can multipotent stem cells make?

A

certain types of tissues

20
Q

What are some examples of totipotent stem cells?

A
  • fertilized egg

- cells from very early embryo (4 days old)

21
Q

Where can pluripotent stem cells be found?

A

embryo

22
Q

Where can multipotent stem cells be found?

A
  • bone marrow

- amniotic fluid

23
Q

What type of stem cells is found in the skin and the liver?

A

unipotent

24
Q

What do eukaryotic cells contain that complicate cell division?

A
  • nuclear membrane
  • organelles
  • multiple chromosomes
25
Q

WHAT IS A COMPLETE ARRAY OF CHROMOSOMES CALLED?

A

(answer - genome? karyotype?)

26
Q

What is the term for the physical map of a complete array of chromosomes?

A

karyotype

27
Q

What are 2 chromosomes of the same type called?

A

homologous

28
Q

What does homologous mean?

A

contain the same genes

29
Q

When are eukaryotic chromosomes duplicated?

A

before division

30
Q

What are the 2 kinds of cells in eukaryotes?

A

somatic and sex cells (gametes)

31
Q

What is the main difference between somatic cells and sex cells?

A

contain different number of chromosomes

sex cells are haploid while somatic are diploid

32
Q

How many chromosomes are in a human somatic cell?

A

46

33
Q

If a cell has 36 chromosomes, what is 2N? N?

A
2N = 36 (diploid number)
N = 18 (haploid number)
34
Q

How many sets of chromosomes are in somatic cells?

A

23 pairs - 2 sets

35
Q

What does diploid mean?

A

having 2 sets of chromosomes

36
Q

What are cells called when they only have 1 set of chromosomes?

A

haploid

37
Q

How many chromosomes are in human sex cells?

A

23

38
Q

What is the term to describe a cell with 3 sets of chromosomes? 4?

A

3: triploid
4: tetraploid

39
Q

What is chromatin made of and in what relative quantities?

A

60% protein

40% DNA

40
Q

What is chromatin?

A

an uncondensed chromosome

41
Q

What is a duplex chromosome?

A

double-stranded

42
Q

What does chromatin wrap around to form a nucleosome?

A

histones (small protein complexes)

43
Q

SUPERCOILING QUESTION

A

(answer)

44
Q

NUCLEOSOME QUESTION

A

(answer)

45
Q

What do cells need to do in order to divide?

A

1) replicate DNA
2) replicate organelles
3) separate the DNA (and organelles)
4) divide the cytoplasm

46
Q

What are chromosomes called before duplication?

A

single chromatid

47
Q

What are sister chromatids?

A

2 identical chromosomes (formed by chromosome duplication)

48
Q

WHAT HOLDS TOGETHER TWO SISTER CHROMATIDS?

A

CENTROMERE? KINETOCHORE?

49
Q

What are the two overall phases of the cell cycle?

A

interphase and mitotic phase

50
Q

Approximately how long does the cell spend in interphase?

A

90% of the cell cycle

51
Q

What phase of the cell cycle does the cell spend 10% of the time in?

A

mitotic phase

52
Q

What part of the cell cycle does the cell spend 50% of its time in?

A

S stage (synthesis)

53
Q

Which cell cycle stage is most variable?

A

G1