Brainscape's Knowledge GenomeTM

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


See full index

Cell Biology > Chapter 10 > Flashcards

Chapter 10 Flashcards

1
Q

Bacteria divide by

A

binary fission. Asexual reproduction

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

Bacterial genome

A

Single, circular chromosome tightly packed in the cell at the nucleoid region. (Prokaryotes don’t have nuclei). New chromosomes are partitioned to opposite ends of the cell

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

Septum

A

Forms to divide cell into 2 cells
Protein FtsZ

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

ORI. Termination site

A

Origin of replication of chromosomes

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

Eukaryotes chromosomes

A

Linear chromosomes. Single or double armed

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

Human chromosomes

A

46 chromosomes in 23 nearly identical pairs

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

22 pairs

A

Autosomal (do nothing to determine sex)
XX=Female
XY= Male

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

Typical human chromosome

A

Composed of chromatin complex of DNA and protein
140 million nucleotide long.
Over 2 meters of DNA inside a diploid human nucleus

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

Heterochromatin

A

More condensed
Silenced or fewer genes (Methylated)
Gene poor (High AT content)
Stains darker

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

Euchromatin

A

Less condensed
Gene expressing
Gene rich (Higher GC content)
Stains lighter

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

Levels of Chromatin organization

A

1 Naked DNA
2 Nucleosome - first level of wrapping
3 Solenoid
4 Chromatin loops
5 Chromosomes

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

Nucleosome

A

Complex of DNA and histone proteins (ball like)
DNA duplex coiled around 8 histone proteins every 200 nucleotides
Histones are positively charged. DNA phosphate groups (in nucleotide) negatively charged

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

Solenoid

A

Nucleosomes wrapped into higher order coils
Leads to a fiber 30 nm diameter.
During mitosis chromatin in solenoid arranged around scaffold of protein to achieve maximum compaction

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

Karyotype

A

Particular array of chromosomes in an individual organism. (Seeing genome)

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

Diploid vs Haploid

A

Diploid (2n) 2 copies of all chromosomes, 1 from mom 1 from dad. Somatic cells- nothing to do with reproduction
Haploid (n) 1 set of chromosomes. Sperm or ovum. Sex or germ line cells

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

Homologous

A

Pairs of chromosomes

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

SRY region

A

Area that males turn on after the beginning and during the embryotic process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Before DNA replication

A

each chromosome composed of a single DNA molecule (single armed) (monad)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

After DNA replication

A

each chromosome is composed of 2 identical DNA molecules, held together by cohesin proteins. One chromosome composed of 2 sister chromatids.

20
Q

Kinetochores

A

Microtubules attach to move chromosomes

21
Q

Human mitosis

A

Somatic cells. Growth, repair, regeneration. Start with one cell. One round of cell division. End with 2 identical new cells: Daughter cells.

22
Q

Eukaryotic cell cycle two phases

A

M phase/cytokinesis: Eukaryotic nuclear division (mitosis) and cell division (cytokinesis)
Interphase (bigger part) - Cell is being a cell, nucleus is visible, cell metabolic functions, including DNA replication, occur. Begins after cytokinesis and ends when mitosis starts.

23
Q

Interphase phases

A

G1 (Gap phase 1) - Growth of cell, longest phase. Primary growth phase
S (Synthesis) - Single to double arm. DNA replication create sister chromatids attached at centromere
G2 (Gap phase 2) - Some growth. Mostly preparation for M phase. Organelles replicate, microtubules organize, chromosomes coil more tightly

24
Q

Resting phase G0

A

Cells often pause in G1 before DNA replication and enter a resting state. Spend more or less time here before resuming cell division. Most cells in animal body are in G0. Muscle and nerve cells remain there permanently. Liver cells can resume G1 phase in response to factors during injury.

25
Q

Centromere

A

Point of constriction

26
Q

Kinetochore

A

Attachment site for microtubules

27
Q

Cohesin

A

Protein attachment for chromatids at centromere

28
Q

M (Mitosis) Phase

A

Prophase
Prometaphase
Metaphase
Anaphase
Telophase

29
Q

Prophase

A

Chromosomes condense and appear as two sister chromatids held together at the centromere. Nuclear envelope breaks down. Mitotic spindles (from centrioles) begin to form on opposite sides of cell. Asters-radial array of microtubules in animals (not plants. Golgi and ER are dispersed

30
Q

Prometaphase

A

After disassembly of nuclear envelope, chromosomes attach to microtubules at kinetochores from opposite poles and begin to move to equator

31
Q

Metaphase

A

Alignment of chromosomes along metaphase plate. Under tension from microtubules

32
Q

Anaphase

A

Begins when centromeres split. Removal of cohesin proteins. Sister chromatids pulled towards opposite poles. No longer chromatids, now chromosomes

33
Q

Telophase

A

Spindle apparatus disassembles, Nuclear Envelope forms. Chromosomes begin to uncoil and disperse. Nucleolus reappears. Golgi and ER reform

34
Q

Cytokensis

A

Cleavage of cell into equal halves. Animal cells constriction of actin filaments produces a cleavage furrow. Plants form cell plate between nuclei

35
Q

Control of cell cycle 2 concepts

A

1 Cycle has two irreversible points
A. Replication of genetic material (S-phase)
B. Separation of the sister chromatids (anaphase)
2. Cell can be put on hold at specific points called checkpoints. Process checked for accuracy, allows for response to internal and external signals

36
Q

3 Checkpoints

A
  1. G1/S checkpoint - Decides whether or not to divide
  2. G2/M checkpoints - Makes a commitment to mitosis, assesses success of DNA replication, can stall the cycle if DNA has not been accurately replicated
  3. Late metaphase (Spindle Checkpoint) - Cell ensures that all chromosomes are attached to the spindles by microtubules.
37
Q

Cyclin-dependent kinases

A

(Cdks) Enzyme kinases that phosphorylates proteins (attaches phosphate group). Primary mechanism of cell cycle control. Cdks partner with different cyclins at different points in the cell cycle. Cdk itself controlled by phosphorylation.

38
Q

Cdk-cyclin complex

A

Also called Mitosis-promoting factor (MPF) promotes mitosis
Activity of Cdk controlled by pattern of phosphorylation. Cdk has active and inactive sites for cyclin to bind to

39
Q

Anaphase-promoting complex (APC)
Cyclosome (APC/C)

A

Function is to trigger anaphase itself. Marks securin for destruction. Securin inhibits separase (destroys cohesin). No securin = no inhibition of separase, separase destroys cohesin and sister chromatids can separate. APC marks securin for destruction

40
Q

Securin

A

Enzyme found in all cells. Secures cohesin and inhibits anaphase. Need to remove securin for anaphase to occur

41
Q

Separase

A

Enzyme that destroys cohesin once securin is is removed

42
Q

Cancer and two genes

A

Unrestrained, uncontrolled growth of cells. Failure of cell cycle control.
Tumor suppressor genes
Proto-oncogenes

43
Q

Tumor-suppressor genes

A

Genes whose activity includes preventing tumor formation (unwanted cell growth/division). Both copies of a tumor-suppressor gene must lose function for the cancerous phenotype to develop.
p53: G1 checkpoint

44
Q

p53

A

G1 checkpoint monitors integrity of DNA and prevents the development of mutated cells.
Abnormal p53 fails to stop cell division, damaged cells divide and cancer develops

45
Q

Proto-oncogenes

A

Normal cellular genes that become oncogenes when mutated. oncogenes can cause cell to be cancerous. Only one copy of proto-oncogene needs to undergo mutation for uncontrolled division to take place. Some proto-oncogenes encode receptors for growth factors, if receptor is mutated on, cell no longer depends on growth factors.

Cell Biology (12 decks)

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