gb prefinals Flashcards
1
Q
is a cycle of stages that a cell pass through to allow them to divide and produce new cells. It is sometimes referred to as “cell division cycle.”
A
cell cycle
2
Q
The two main parts of the cell cycle are:
A
mitosis and interphase.
3
Q
- New cells are born through the division of their “parent” cell, producing two “daughter” cells from one single “parent” cell.
A
Mitosis
4
Q
- the longest part of the cell cycle; the phase of growth and DNA replication between mitotic cell divisions.
A
Interphase
5
Q
10
hrs
A
Gap1
6
Q
5-6
hrs
A
Synthesis
7
Q
3-4
hrs
A
Gap2
8
Q
2
hrs
A
Mitosis
9
Q
64 mins
A
Prophase
10
Q
8 mins
A
Metaphase
11
Q
12 mins
A
Anaphase
12
Q
32 mins
A
Telophase
13
Q
2 weeks
A
Skin cell
14
Q
4 months
A
Red blood cell
15
Q
300-500 days
A
Liver cell
16
Q
4-5 days
A
Intestine (internal lining)
17
Q
16 years
A
Muscles & other tissues
18
Q
consists of at least three distinct stages during which the cell grows, produces new organelles, replicates its DNA, and finally divides.
A
Interphase
19
Q
In this stage, the cell gets nutrients, creates and uses proteins and other molecules, and starts the cell division process by replicating the DNA.
A
Interphase
20
Q
Interphase is divided into three stages:
A
Gap 1 (G1 stage), Synthesis (S stage), and Gap 2 (G2 stage).
21
Q
The purpose of interphase in all cell types is
A
to ready the cell for cell division, which happens in a different stage of the cell cycle.
22
Q
- During this stage, the cell performs its normal functions, and grows in size. The cell replicates the necessary proteins (RNA and protein synthesis) and organelles like ribosomes and mitochondria (includes chloroplasts in the case of plants).
This allows the cell to increase its energy production and overall metabolism
A
Gap 1 (G1 Stage)
23
Q
where the cell checks if it is ready for the next stage.
Is the cell big enough to accommodate genetic replication?
Is the environment (in the cell) suitable?
A
G1 checkpoint”
24
Q
where the cell makes a copy of its entire set of chromosomes.
All of the cell’s resources (like energy) are dedicated to replicating the DNA. Therefore, cell functions that has no business in DNA replication is slowed.
A
synthesis
25
This process starts with the two entwined strands of DNA being “unzipped” by various proteins. Other proteins, known as polymerase enzymes, start creating new strands to pair with each half of DNA.
synthesis
26
Thus in this stage, the cell which has normally have a 46 chromosomes (diploid or 2n) has double the amount of chromosomes (4n).
synthesis
27
which is also characterized by protein production.
(Gap 2 or G2)
28
What happens here is the cell adds volume to the cytoplasm (increasing the size of the cell) and replicates a lot of organelles. For animal cells, mitochondria are replicated so the cell can provide more energy for the dividing cells. As for plant cells, mitochondria and chloroplasts must be replicated to provide the daughter cells with organelles capable of producing enough energy.
(Gap 2 or G2)
29
Organelles and structures such as centrioles and nucleolus are also duplicated for cell division.
(Gap 2 or G2)
30
G2 is the shortest in the whole interphase process.
(Gap 2 or G2)
31
Has the DNA been replicated?
Is the cell big enough?
Is the environment suitable for cell division?
(Gap 2 or G2) checkpoint
32
is the step in the cell cycle that the newly duplicated DNA is separated, and two new cells are formed.
Mitosis
33
---is important because:
For single-celled eukaryotes, this is their only way of reproduction (asexual)
For multi-celled eukaryotes, mitosis is how a single zygote develop into another organism.
Growth and development of an organism
Cell regeneration for tissue/organ repair, wound healing
Mitosis
34
Mitosis is important because:
For single-celled eukaryotes, this is their only way of reproduction (asexual)
For multi-celled eukaryotes, mitosis is how a single zygote develop into another organism.
Growth and development of an organism
Cell regeneration for tissue/organ repair, wound healing
35
The M stage is divided into
mitosis and cytokinesis.
36
During the prophase, the DNA is condensed. During interphase, when the DNA is replicated, it is in a loose and open form to allow enzymes to do their work on the DNA and create a new strand. However, if the DNA is in this form (chromatin), they will tangle and break if the cell will try to move it.
A. Early Prophase
37
During prophase, the cell’s machinery packages the DNA around special proteins, called histones, which allow it to condense into very tight packages (what do you call this form?). These tight packages of DNA can now be moved around with ease.
Centrioles start to migrate on the cell’s poles and there’s also production of early spindle fibres. The nuclear envelope starts to disappear.
A. Early Prophase
38
In order for the duplicated chromosomes to be split up, the microtubules have to reach them. In prometaphase, the nuclear envelope surrounding the chromosomes falls apart. This membrane was separating the DNA from the cytosol of the cell. When the nuclear envelope dissolves, the microtubules are allowed to extend from the centromeres to the chromosomes.
B. Prometaphase (Late Prophase)
39
Each chromosome has a an area that is called centromere and each centromere has a kinetochore. The microtubules attach to these kinetochores, allowing the cell to move the chromosomes around. Microtubules from each side of the cell will attach to each chromosome during prometaphase.
B. Prometaphase (Late Prophase)
40
Each chromosome has a an area that is called
centromere
41
This is where the microtubules will start pulling on the chromosomes. Each side will pull with equal force, and the chromosomes will end up in the middle of the cell. This area is called the metaphase plate. The chromosomes aligned on the metaphase plate represent two full copies of DNA.
. Metaphase
42
Each chromosome lines up next to its sister chromatid, or cloned DNA strand. In this way, when the microtubules pull the chromosomes apart, each cells gets an entire functioning genome.
Metaphase
43
The sister chromatids, identical clones of the same part of DNA, are bound together at their centromeres. During anaphase, the proteins that connect these chromatids are destroyed. Each now its own chromosome, the identical halves can be pulled to each cell.
3. Anaphase
44
The final phase of mitosis, telophase, occurs when the chromosomes are pulled toward each centriole, and a cleavage furrow forms in the cell. The chromosomes will eventually get a nuclear envelope formed around them, and become their own cells.
4. Telophase
45
The centrioles will dissolve, and each cell will resume normal functioning. One crucial last step, cytokinesis, is needed before the daughter cells function. This last step is not a step of mitosis, but rather the beginning of interphase. Once divided, the cells can resume growing.
4. Telophase
46
This is the process of separation of the two daughter cells that had undergone mitosis. This is a separate process from mitosis.
cytokinesis
47
This is a metabolic state meant only to maintain the daughter cell, not prepare for cell division.
(Gap 0)- Alternate Route
48
Occurs in somatic cells or body cells
| Retains the number of chromosomes
diploid
Mitosis
49
occurs in reproductive cells or sex
cells
```
reduces the number of chromosomes
into half (haploid)
```
Meiosis
50
are cells in the body EXCEPT the gametes or sex cells.
Somatic cells
51
in the most basic definition, is uncontrolled mitotic cell division. This usually happens when:
Genes that suppresses or stops cell division (tumour suppressors) are turned off; or
Genes that encourage cell division (oncogenes) are hyperactive.
Cancer,
52
are mutated (have a different form) in most instances and leech off or compete for nutrients from healthy ones.
Cancerous cells
53
Each daughter cell always contain the same genetic information as their ----
parent cell.
54
on the other hand, can only happen in sex cells or gametes. It is a type of division where a single cell divides twice to produce four cells containing half the original amount of genetic information.
Meiosis,
55
After a complete division under meiosis, instead of the cell having 46 chromosomes, they only have -----per daughter cell.
23 chromosomes or haploid
56
Take note that the the pairings of the chromosomes here (meiosis) are ---, meaning that the pairs of the chromosome have the same genetic information.
homologous
57
are variations of a gene that can result in different traits in living things.
Alleles
58
is comprised of a paternal chromosome (father-side traits) and a maternal chromosome (mother-side traits). These chromosomes pair up during meiosis.
The homologous pair
59
Between prophase I and metaphase I, homologous chromosomes can swap parts of themselves that house the same genes. This is called
crossing-over or recombination
60
This law states that traits are inherited independently of each other.
law of independent assortment.
61
In metaphase I, the homologous pairs of chromosomes line up on the metaphase plate, near the center of the cell. This step is referred to as a
reductional division.
62
While the chromosome line up on the metaphase plate with their homologous pair, there is no order upon which side the maternal or paternal chromosomes line up. This process is the molecular reason behind the----
law of segregation in genetics.
63
The daughter cells as a result of meiosis for males are all sperm cells (4 in total). On the other hand, daughter cells for females after meiosis results to one egg cell and three polar bodies.
The daughter cells as a result of meiosis for males are all sperm cells (4 in total). On the other hand, daughter cells for females after meiosis results to one egg cell and three polar bodies.
64
is a small haploid cell that is formed concomitantly as an egg cell during oogenesis, but generally does not have the ability to be fertilized.
A polar body
65
The phenomenon where unequal separation of genes in meiosis happens is called .
nondisjunction
66
This happens when the chromosome “gets lost” due to non-connection to their respective centromere and spindle fiber. When cell division comes, the daughter cells end up with one less chromosome in one and one extra chromosome in the other.
nondisjunction
67
If nondisjunction causes a missing chromosome in a haploid gamete, the diploid zygote it forms with another gamete will contain only one copy of that chromosome from the other parent, a condition known as
monosomy.
68
Conversely, if nondisjunction causes a homologous pair to travel together into the same gamete, the resulting zygote will have three copies, a condition known as
trisomy.
69
The term ---applies to any of these conditions that cause an unexpected chromosome number in a daughter cell.
aneuploidy
70
can happen to humans. For instance, the underlying causes of Klinefelter's syndrome and Turner's syndrome are errors in sex chromosome number, and Down syndrome is caused by trisomy of chromosome 21.
Aneuploidy
71
- a number and visual appearance of the chromosomes in the cell nuclei of an organism
karyotype
72
is commonly known as Down syndrome. Down syndrome can affect a person's cognitive ability and physical growth, cause mild to moderate developmental issues, and present a higher risk of some health problems.
Trisomy 21
73
Formation and development of sex cells – sperm and egg cells through meiosis.
gametogenesis
74
2 types of
| gametogenesis
Spermatogenesis
| Oogenesis
75
primary
| spermatocyte
1:1
76
secondary
| spermatocyte
1:2
77
spermatids
1:4
78
spermatozoa
1:4
79
```
Function:
To move and carry genetic
information to the egg.
Structure:
Head: The large head
region of the sperm that
contains DNA.
Midpiece: The narrow
middle part of the cell that
contains mitochondria,
Tail: The wavelike motion
of the flagellum propels
the sperm forward.
```
SPERM
80
Site of spermatogenesis
TESTIS
81
starts at the age of puberty or adolescence
Spermatogenesis
82
- normal range for the number of sperm per milliliter.
Below 10 million are considered poor.
40 million to 300 million
83
importance of spermatogenesis
Production of sperm cells
| Reduction of the number of chromosomes in each sex cell from DIPLOID (2N) to HAPLOID (N)
84
Formation and development of the ovum or egg cells in the ovary through meiosis.
oogenesis
85
occurs in the ovary
Oogenesis
86
Women stop producing egg cells at the age of 45-51 (menopausal stage)
Women stop producing egg cells at the age of 45-51 (menopausal stage)
87
Women stop producing egg cells at the age of 50 (menopausal stage)
Women stop producing egg cells at the age of 50 (menopausal stage)
88
End of women’s monthly period
Can occur as early as 40 or as late as 60 (average age of 51)
A series of emotional and physical changes in a women’s body
menopause
89
primary oocyte?
| …
1:1
90
secondary
oocyte?
…
1:1
91
1st Polar body
1:1
92
…ootid
1:1
93
…2nd Polar body
1:3
94
…ovum/ ova
1:1
95
importance of oogenesis
Production of ova or egg cells
| Reduction of the number of chromosomes in each sex cell from DIPLOID (2N) to HAPLOID (N)
