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Biology🧪🌱💦 > Lecture 8 > Flashcards

Lecture 8 Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

Name 4 important structures in cell division

A
  • nucleus
  • nucleolus
  • chromatin (chromosomes)
  • centrosomes (+ microtubules)
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2
Q

What does cell division mean? (2)

A

the ability of organisms to reproduce
+ the continuity of life is based on the reproduction of cells (cell division)

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3
Q

3 roles of cell division

A
  1. Reproduction
  2. Growth and development
  3. Tissue Renewal and repair (skin, cells…)
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4
Q

Between chromatin and chromosomes, which one is tightly coiled and which is loosely arranged?

A

Chromatin: loosely arranged DNA

Chromosomes: tightly coils around protein

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5
Q

which protein are we talking about?

A

histones

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6
Q

Between chromatin and chromosomes, which one is used for dividing?

A

Chromosomes

Chromatin -> DNA when the cell is not dividing (b/c it’s loose)

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7
Q

What controls characteristics like hair, skin, or flower color?

A

they are controlled by genes

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8
Q

Where are genes located?

A

on the chromosomes

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9
Q

TRUE OR FALSE:
Each chromosome is a huge molecule of DNA
(+ protein)

A

TRUE

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10
Q

TRUE OR FALSE:
Each chromosome has DNA made up of nucleotides

A

TRUE

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11
Q

TRUE OR FALSE:
Each chromosome contains a very small number of genes

A

FALSE
contains a LARGE number of genes

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12
Q

TRUE OR FALSE:
Each gene occurs on a SPECIFIC chromosome.

A

TRUE (similar to an address)

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13
Q

How many chromosomes do we have?

A

46 chromosomes (23 pairs)

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14
Q

In humans, how many different kinds of chromosomes do we have?

A

23 different kinds of chromosomes
(23 mom + 23 dad = 46)

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15
Q

What is a karyotype?

A

an organized profile of a person’s chromosomes

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16
Q

How are the chromosomes arranged?

A

chromosomes arranged by size
(from largest to smallest)

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17
Q

What are autosome chromosomes?

A

An autosome is any chromosome that is not a sex chromosome

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18
Q

How many autosomes do we have?

A

22 autosomes (non-sex chromosomes)

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19
Q

How many sex chromosomes de we have?

A

only 1 sex chromosome

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20
Q

Why are Karyotypes useful and important?

A

Karyotypes can be checked for irregularities in the number or structure of chromosomes
(important for scientists to quickly identify chromosomal alterations)

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21
Q

What does it mean if there is an Abnormal Number of Chromosomes?

A

= Genetic Diseases

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22
Q

What are Non-reproductive chromosomes called?

A

autosomal or autosomes
(they don’t code for sex characteristics (ex. male/female))

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23
Q

Where can autosomes be found?

A

in somatic cells (non-gametic cells)
AND gametes (but in different quantities)

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24
Q

Where can we find sex chromosomes (X & Y)?

A

also in somatic cells (non-gametic cells) AND gametes (but in different quantities)

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25
Q

What is a zygote?

A

a fertilized egg

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26
Q

what is a fertilized egg?

A

when a sperm cell and egg cell unite (nuclei fuse forming 1 nucleus)

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27
Q

How many chromosomes in total does the new individual get?

A

46 CHROMOSOMES (1 complete set of 23 chromosomes from each parent)

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28
Q

Sexual reproduction creates what?

A

genetically unique individuals

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29
Q

How do individuals grow?

A

by increasing cell number (cell divides into 2 - 4 - 8…)

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30
Q

TRUE OF FALSE:
An exact copy of every chromosome is distributed to each cell in the division process

A

TRUEEE

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31
Q

What is the cell cycle?

A

time between when a cell is formed and when it divides
(forms 2 new daughter cells)

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32
Q

What are the 2 types of cell division?

A

Mitosis and Meiosis

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33
Q

IN MITOSIS:
1. what are the results:
2. it occurs during what?

A
  1. Results in identical body cells
  2. Occurs during growth and repair
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34
Q

IN MEIOSIS:
1. Gives rise to what?
2. same or different # of chromosomes?

A

Gives rise to gametes that have HALF the number of chromosomes as the original cell

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35
Q

Let’s analyze and understand everything about mitosis…
what is mitosis?

A

(somatic) cell division
-> division of cells that aren’t gametes

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36
Q

What is the result of mitosis?

A

resulting in 2 daughter
cells, each with the same
# of chromosomes as the
parent cell

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37
Q

The cell cycle is divided into different stages, name the 3 general ones

A
  1. Growth of the cell following division
  2. Copying of genetic info
  3. Distribution of copies of daughter cells
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38
Q

There are 2 main stages in the cell cycle, name them

A

1) Interphase (environ 95%)
2) Mitotic phase (much shorter environ 5%)

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39
Q

How many phases are in interphase? and when does it occur?

A

3 phases of interphase + occur b/w the time a cell is formed and when it begins the division process

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40
Q

name all 3 phases of interphase:

A

G1: (Growth 1)
S: DNA Synthesis
G2: (Growth 2)

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41
Q

when does G1Phase begin?

A

as soon as daughter cell formed

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42
Q

G1Phase: synthesis or growth?

A

GROWTH
period of active growth

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43
Q

What generally happens in G1?

A

the cell grows physically larger, copies organelles

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44
Q

What comes after G1?

A

S phase

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45
Q

What generally happens in S phase?

A

DNA replication
(the cell synthesizes a complete copy of the DNA in its nucleus)

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46
Q

Copied chromosomes are referred to as what?

A

sister chromatids

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47
Q

TRUE OR FALSE:
sister chromatids both contain the SAME genetic info?

A

TRUE

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48
Q

sister chromatids are physically attached by what?

A

a centromere

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49
Q

are chromosomes condensed at this stage?

A

NOOO
chromosomes are not condensed yet, they are simply linked to the sister copy/clone

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50
Q

when are the sister chromatids condensed?

A

in PROphase

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51
Q

what happens to the number of chromatids/chromosomes during mitotic chromosome replication?

A

chromatid number is 2x number of chromosomes
23pairs => 46 pairs of chromatids = 92 sister chromatids
RECAP:
46 chromosomes and 46 chromatids TO 46 chromosomes and 92 chromatids

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52
Q

What do we call the final stage of Interphase?

A

G2 Phase (occurs after S phase of interphase)

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53
Q

What generally happens in G2?

A

the cell increases slightly + begins preparation for the mitotic phase of the cycle

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54
Q

What do we have at the end of Interphase (3)?

A
  • chromosomes have been copied
  • centrosomes duplicated
  • spindles have formed
55
Q

Mitotic phase is a series of steps that results in what?

A

a distribution of EXACT copies of chromosomes to each developing daughter cell

56
Q

name all steps of mitosis (5)

A

ia. Prophase (early)
ib. Prometaphase (late)
ii. Metaphase
iii. Anaphase
iv. Telophase

Pmat

57
Q

What comes after telophase that isn’t part of the cell division septs?

A

Cytokinesis

58
Q

First of all, what happens in prophase (early)?

A

DCC/ NE/ DCS/ MXA

DCC: DNA compacts/condenses
NE: Nuclear Envelope breaks
DCS: Duplicated Centrosomes (G2) separate
MXA: Microtubule fibers extend b/w centrosomes

59
Q

In prophase (early), how does the DNA stay? Are they still called sister chromatids?

A

DNA will STAY in this chromosome form until the end of telophase
YES, they are still called sister chromatids

60
Q

In prophase (early), the duplicated centrosomes separate and begin to move around what organelle?

A

around the nucleus

61
Q

In prophase (early), the microtubule fibers extend b/w centrosomes forming WHAT?

A

forming the mitotic spindle

62
Q

What comes after prophase (early)?

A

Prometaphase (late prophase)

63
Q

What happens in Prometaphase (late prophase)?

A

NEB/ CO/ MAK/ ND
NEB: Nuclear Envelope broken down
CO: Centrosomes at Opposite ends of the cell
MAK: Microtubules to attached to Kinetochores
ND: Nucleoli disappear

64
Q

What is kinetochore?

A

centromere region

65
Q

What comes after Prometaphase?

A

Metaphase

66
Q

When does Metaphase happen?

A

when all of the chromosomes are ALIGNED along the CELL MIDLINE (metaphase plate)

67
Q

What happens in Metaphase?

A

each chromosome attached to protein fibers coming from opposite poles (with overlapping non-kinetochore microtubules)

68
Q

What comes after metaphase?

A

anaphase (a = apart)

69
Q

What is the main thing that happens during anaphase?

A

the sister chromatids SEPARATE

70
Q

So how do they separate?

A

the centromeres break which separate the chromatids

71
Q

How are the chromatids called now?

A

chromosomes

72
Q

Are they still clones of each other or not?

A

THEY STILL ARE CLONES, but they are no longer attached at the
centromere / kinetochore

73
Q

Where are the chromosomes pulled to?

A

to the opposite ends of the cell (using microtubules as tracks)

74
Q

Does the cell elongate or not?

A

it does elongate

75
Q

At the end of anaphase, what should we see from each pole of the cell?

A

each pole has a COMPLETE set of chromosomes

76
Q

little note: so once chromatids are no longer attached to their duplicates, how do we call them?

A

chromosomes

before 1 chromosome (2 chromatids)
then 2 chromosomes

77
Q

What comes after Anaphase

A

Telophase

78
Q

How are the chromosomes at the end of anaphase and the beginning of telophase?

A

One copy of each Chromosome
present in at opposite ends of the
cell

79
Q

What disappear?

A

the spindle fibers

80
Q

What forms around the chromosomes?

A

nuclear membrane forms

81
Q

what REappears?

A

the nucleolus

82
Q

Chromosomes start to “relax”. What does this mean?

A

unwind/ less compact (return to chromatin form/state)

83
Q

Recap of telophase:

A

SFD/ NMF/ NA/ CX
SFD: the spindle fibers disappear
NMF: nuclear membrane forms
NA: Nucleolus REappears
CX: Chromosomes relax

+ light indentation (not fully separated)

84
Q

Does Telophase mark the end of mitosis?

A

YESs, even if cell
the division is not entirely
complete

85
Q

What comes after telophase?

A

Cytokinesis

86
Q

What happens in cytokinesis?

A

Cell gradually pinches in
along midline

87
Q

What does this form?

A

forms a cleavage furrow

88
Q

What is the result of cytokinesis?

A

2 daughter cells with exact
same genetic information

89
Q

Each daughter cell has 2 copies of each chromosome, we call them homologous pairs (what does this entail?)

A

homologous pairs = have genes for same traits, same size/shape

90
Q

What can happen at the end?

A

the cell may enter G1 of Interphase (can repeat cycle)

91
Q

GIVE A BRIEF SUMMARY OF ALL THE STEPS

A
  1. DNA replication (S phase of Interphase) + formation of 2 sister chromatids
  2. In Prophase, NM breaks down + spindle fibers assemble
  3. Metaphase: sister chromatids line up along the metaphase plate
  4. Anaphase: sister chromatids SEPARATE and move to opposite ends of the cells
  5. Telophase: Nuclear envelope reappears around chromosomes
  6. Cytokinesis: parent cell DIVIDES (forming 2 daughter cells)
  7. Each daughter cell has 2 copies of each chromosome (homologous pairs)
92
Q

Is mitosis in plant cells similar or completely different?

A

it’s similar

93
Q

What is the main difference?

A

there are no centrioles, but have microtubule organizing centers
+
major difference in cytokinesis: Cells can’t pinch in half like animal cells (daughter cells are separated by a cell plate)

94
Q

What happens during cytokinesis for plant cells?

A
  • vesicles from Golgi carry cell wall components and travel to the center of dividing cells
  • Cell plate forms at the center and
    proceeds to the cell membrane
95
Q

What happens in Prokaryotic cells?

A

Binary fission

96
Q

What is Binary fission?

A

division in half

97
Q

It’s important to remember that most bacteria have a single ______ that forms the nucleiod

A

have a single circular chromosome

98
Q

What is the result after the chromosome replicates?

A

the 2 resulting chromosomes migrate to polar ends of cell (which elongates the cell to provide room for both chromosomes)

99
Q

What then happens to the plasma membrane?

A

the PM grows inward at the center of the cell (between the nucleoid region)

100
Q

What is the result of this separation?

A

2 daughter cells

101
Q

The cell cycle regulation has checkpoints… for what reason?

A

the cell cycle is VERY tightly controlled, at specific times, the cells check themselves to assess if everything is good (checkpoint)

102
Q

What happens when everything is OK?

A

the cycle continues to the next stage

103
Q

What happens when there is smt wrong?

A

the cycle does NOT continue until the error is fixed

104
Q

If the error CAN NOT be fixed, the cell will ____ _____

A

undergo apoptosis

105
Q

What is apoptosis?

A

programmed cell death
(cell suicide) (b/c it’s not a good idea to make a copy of a damaged cell)

106
Q

How many checkpoints are there?

A

3 main checkpoints

107
Q

name all 3 checkpoints:

A

G1 checkpoint
G2 checkpoint
M checkpoint

108
Q

Tell me what G2 checkpoint is influenced by

A
  • cell size
  • DNA damage
  • DNA replication
109
Q

Tell me what G1 checkpoint is influenced by

A

G1 checkpoint:
- Growth factor proteins
- nutrients
- cell size
- DNA change

110
Q

Tell me what M checkpoint (metaphase-anaphase) is influenced by

A
  • chromosome attachments to spindle
111
Q

What is the purpose of all these checkpoints?

A
  • not a good idea to copy a damaged cell
  • cancer prevention
112
Q

Why cancer prevention?

A

cancer is a disease of the cell
a cancerous cell multiplies out of control (excessive cell growth and division)
the checkpoints are ignored

113
Q

Is the cell under control?

A

NO, The cell is no longer under
the control of mechanisms
that normally regulate cell
growth and division.
(escape normal control methods)

114
Q

Spontaneous mutations (by accident) during what?

A

during DNA replication

115
Q

Mutagens can occur by what?

A

by various agents (chemical, radiation, etc.) that change the genetic info of an organism
= thus increases the frequency of mutations

116
Q

What is called a mutagen?

A

anything that can bring about a mutation in DNA

117
Q

Give an example of a mutagen

A

too much UV light exposure which damages the DNA

118
Q

Cancer development is done in 2 ways, which ones?

A

Benign tumors and Malignant tumors

119
Q

Tell me more about the Benign tumors:

A
  • mass of cells (lump) that do not invade neighboring tissues (may grow very largre)
120
Q

Are Benign tumors considered cancer

A

NO

121
Q

Can they be removed?

A

yes

122
Q

Can Benign tumors spread?

A

NO

123
Q

Tell me more about Malignant tumors:

A
  • a mass of cells that invade neighboring tissues
  • can impair the functioning of one or more organs
124
Q

Are Malignant tumors considered cancerous?

A

YES

125
Q

Can Malignant tumors spread?

A

YES

126
Q

the spread of cancer cells to locations distant from their original site, how do you call this?

A

metastasis (it’s the release of cancerous cells into the bloodstream)

127
Q

Can Benin tumors metastasize?

A

NO, only malignant tumors can metastasize

128
Q

What are the steps of cancer development of a malignant tumor?

A
  1. a tumor grows from a single cancer cell
  2. cancer cells invade neighboring tissue
  3. cancer cells spread through lymph and blood vessels to OTHER parts of the body
  4. a small % of cancer cells may survive and establish a NEW tumor in ANOTHER part of the body
129
Q

name all 3 possible treatments

A
  1. Surgery
  2. High-energy radiation
  3. Chemotherapy
130
Q

Which treatment would you use for a tumor that appears to be LOCALIZED?

A

High-energy radiation

131
Q

What does High-energy radiation do?

A
  • non-specific damage to DNA
  • cancer cells have LOST their ability to repair DNA
132
Q

Metastatic tumors are treated with what treatment?

A

Chemotherapy

133
Q

What does chemotherapy do?

A
  • damage to actively diving cells
  • taxol freezes the mitotic spindle by preventing microtubule formation
134
Q

What are some side effects of chemotherapy?

A

nausea, immune suppression, hair loss

Biology🧪🌱💦 (21 decks)

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