Cell Cycle Flashcards
1
Q
What are the 3 main stages of the cell cycle?
A
Interphase
Mitosis
Cytokinesis
2
Q
What cycle does a cell spend most of its lifespan?
A
Interphase
3
Q
What is mitosis?
A
The process of somatic or body cells are formed (all regular cells except for sex cells).
4
Q
What does mitosis allow cells or organisms to do?
A
-Grow
-Repair damage
-Replace dead or dying cells
5
Q
What are the stages of mitosis?
A
Propase
Metaphase
Anaphase
Telophase
6
Q
What does asexual reproduction produce?
A
2 identical offspring
7
Q
What is Meiosis responsible for in offspring?
A
Variation
8
Q
What is the purpose of Meiosis?
A
To make daughter cells with exactly half as many chromosomes as the mother cell
9
Q
What is a haploid?
A
A cell with half the number of chromosomes
10
Q
What is a diploid(2n)?
A
A cell with 2 sets of chromosomes ( 1 set from father and 1 set from mother).
11
Q
What are gametes?
A
Reproductive cell (egg or sperm).
12
Q
What is replication?
A
Process of duplicating a chromosome.
13
Q
What are replicated copies called?
A
Sister chromatids
14
Q
What is Synapsis?
A
In prophase l when chromosomes pair up and form a tetrad.
15
Q
What is crossing over?
A
Genetic material between non-sister chromatids can cross over causeing the chromatids to become gentically destinct (no longer identical).
The exchange of chromosomal segments between a pair of homologous chromosomes.
16
Q
What are the long twisted strands in DNA called?
A
Double helix
17
Q
What is a Chromatin?
A
A single strand of DNA found in the nucleus.
18
Q
What are Chromosomes?
A
Two long twisted, identical strands of DNA.
19
Q
What do the “backbones” of the DNA ladder consist of?
A
Alternating sugar molecules (deoxyribose), and phosphate molecules>
20
Q
What is a nucleotide?
A
A sugar, phosphate and nitrogen base molecule.
21
Q
What is a “rungs” and how many are their?
A
Nitrogenous bases (also called base pairs) and only 4.
22
Q
What are the “rungs” and what can they link with?
A
A (adenine) will only link with T (thymine).
C (cystosine) will only link with G (guanine).
23
Q
What is a Codon?
A
The sequence of 3 letter nucleotides that make an instruction to form a particular amino acid.
24
Q
What is a gene?
A
A segment of DNA with enough codons to produce one specfic protien molecule.
A long section of DNA that determines a characteristic.
25
How many amino acids link together to make a protein?
Hundreds of thousands
26
What do proteins make up?
Make up most of the structure of cells and tissues, also enzymes and hormones.
27
How many genes does each human have?
20-25 thousand
28
What is the appearnace of a cells genetic material at prophase of mitosis?
Centrosomes migrate toward poles, growing spindle fibres, dissapearing nuclear membrane and replicated chromosomes.
29
Some drugs that combat cancer inhibit mitosis. What effect would this have on healing times?
Healing time would increase
30
What is the difference between a gamete and zygote?
A gamete is a male or female reproductive cell that fuses together during sexual reproduction to create a zygote.
31
There is 78 chromosomes in dogs. How many chromosomes are in the gamete cell of a dog?
39 chromosomes since gametes are haploids (half number of chromosomes that are in diploid cells).
32
If the number of chromosomes were not reduced during mitosis, how many chromosomes would a human gamete have? How many chromosomes would result after fertilization?
Gametes would have 46 chromosomes (23 pairs).
After fertilization the zygote would have 92 chromosomes (4 sets of 23).
33
What phase of Meiosis are most like the phase of Mitosis?
Metaphase ll, Anaphase ll and Telophase ll.
34
What is a mutation?
Missing, extra or irregular portion of chromosomal DNA.
Offten occurs when there is an error in cell division.
35
What is Deletion?
A piece of the chromosome is removed and lost.
36
What is Translocation?
When a piece of chromosome is removed but gets inserted again upsidedown.
37
What is Duplication?
When a piece of chromosome gets repeated.
38
What is Nondisjunction? When does it happen?
When chromosomes fail to seperate during meiosis. This can happen at anaphase l or ll.
39
What is XX?
A normal female
40
What is XY?
A normal male
41
What is a Karyotype?
A picture of chromosomes in a dividing cell that is arranged in pairs by size.
42
What is Prenatal Genetic Testing?
Test preformed on fetus to determine any genetic disorders.
43
What is Aminocentesis?
A sample of amminotic fluid taken after 14th week of pregnancy.
44
What are the risks with Amniocentesis?
-Chance baby may be poked by the needle
-Less than 1 out of 200 women have a miscaridge
45
What is Chronic Villus Sampling?
A sample of cells taken from the placenta after the 9th week of pregnancy to any determine genetic disorders.
46
What is the difference between how fraternal and identical twins are formed?
Fraternal is when the 2 eggs are released and both are fertilized.
Identical is when a single zygote divides into 2 seperate bodies.
47
What are the 2 ways during meiosis, genetic variation is ensured?
Crossing over and Independent assortment
48
What does "Independent assortment" refer to?
Gametes have diffrent combonations of chromosomes from each parent.
49
What is the difference between trisomy and monosomy?
Monosomy is the loss of a chromosome as a result of non-disjunction while trisonomy is the gain of an extra chromosome as a result of non-disjuction.
50
Why would someone under go Prenatal Genetic Testing?
If they were older than 35.
51
What is cloning to improve human health?
-A way to produce genetically identical organism through non-sexual means.
52
What is Dolly the sheep?
The first mammal to be cloned from a somatic cell
53
What is artficial insemination?
When sperm is artificially placed into a woman's cervix or uterus.
54
What is In-Vitro Fertilization?
Sperm and egg are combined in a petri plate.
The resulting embryo is transferred to the woman's uterus to implant and develop.
55
What are stem cells?
Unspecialized cells that can divide repeatedly.
56
What are Embryonic stem cells?
Cells that can become any type of cell.
Only found in embryos.
57
Why is where stem cells come from so controversial?
Most embryonic stem cells come from embryos that were created in a lab.
58
Who is Gregor Mendel and what did he do?
Considered the father of genetics.
Investigated inheritance in pea plants.
59
What was the first experiment Gregor Mendel did? What did he predict and what actually happened?
He crossed-pollinated a tall pea plant with a short pea plant.
He predicted they would all be medium, but instead they were all the pea plants were tall.
60
What were the dominant and recessive traits in the pea plants?
Dominant-Tall
Recessive-Short
61
What is the Law of Segregation?
Organisms inherit 2 copies of a gene, one from each parent.
Organisms only donate one copy of each gene to their gametes.
62
What was the second experiment that Mendel did? What did he predict and what actually happened?
He cross-polinated the F1 generation plants and observed the F2 generation traits.
He predicted they would all be tall instead, they were a mix of tall and short in a 3:1 ratio.
63
What is the Law of Dominance?
An organism with different forms of a gene will express the form that is dominant.
64
What are alleles and what can they be represented as in Mendel's experiments?
The alternative forms of a gene.
Can be shown as T or t.
65
What advantages does artificial insemination have over traditional methods of selective breeding?
Artificial insemination allows improved access to more potential male donors with highly desirable traits.
66
How do artificial insemination and embryo transfer increase the genetic variation in animals?
Both of these procedures allow for the introduction of new genetic variations from different parts of the world into a given group of animals.
67
What is the function of a vector in gene cloning?
A vector carries the gene of interest into the foreign cell.
68
What is one benefit of developing genetically engineered medical products such as insulin?
Less expensive to produce in large quantities.
69
Why would a company use embryo transfer?
So they can choose desirable characteristics for their animals and shipping embryos is easier than shipping animals and allows the offspring to grow up in their native environment.
70
Some human proteins that are cloned in and isolated from bacteria are not as active as when they are purified from the natural source. Why does this happen?
The bacteria do or don't do something in the protein that would normally occur in the human tissue.
71
What is a monohybrid cross?
A cross of 2 individuals that differ by one trait.
72
How does the F1 generation from a cross between true-breeding plants with opposite forms of a trait differ from the F2 generation?
The F1 generation exhibits only the dominant form of the trait and the F2 generation exhibits both the dominant and recessive forms in a 3:1 ratio.
73
Why did Mendel start with the true breeding plants?
Needed plants with predictable traits so that results were accurate and so that he was able to control his experiments.
74
What is Homozygous?
An individual with identical alleles is also called purebred.
Ex. TT or tt
75
What is Heterozygous?
An individual with 2 different alleles is also called a hybrid.
Ex. Tt
76
What is Genotype?
The unobservable genetic makeup of an organism.
The code that expresses the observable traits.
77
What is Phenotype?
The observable traits of an organism.
What you can see.
78
What is a Punnett square?
A diagram used to predict the possible combination of alleles that can form in offspring.
79
What is incomplete dominance and what are superscripts used to represent?
Dominance is not always the rule, it is actually the exception.
Superscripts are used to represent incomplete dominance.
Red+White=Pink
80
What is seen in incomplete l.
Neither trait is seen but rather a blend of traits.
81
What is codominance?
Both alleles may be dominant therefore both are expressed.
Red+White=red and white
82
What are multiple alleles?
More than 2 alleles can exist for a trait.
However, any one organism can only have 2 of the alleles (one from mom and one from dad).
83
What is an antigen and where is it found?
It stimulates the body's immune system.
It is found on the plasma membrane of red blood cells.
A single gene determines the antigen protein carried on the red blood cell and therefore a person's blood type.
84
What are the blood types and what are their genotypes?
Type A- lAlA or lAi
Type B- lBlB or lBi
Type AB- lAlB
Type O-ii
85
What is a universal donor?
Type O blood
Lacking any antigens so no one will have an immune response to it.
86
What is a universal recipient?
Type AB blood
Has both kinds of antigens so won't react to anyone's blood
87
What is sex linkage?
Refers to when a gene controlling a characteristic is located on a sex chromosome (X or Y)
88
How many genes do X and Y chromosomes carry?
Y- 50-60 genes
X- 1000
89
What is Hemophilia?
A recessive X-linked trait which prolongs the clotting time of blood.
Certain clotting factors in the blood are low or missing.
90
What is a pedigree?
A chart of the genetics history of family over several generations.
91
What are linked genes?
Genes that are on the same chromosome and that tend to be inherited together. Do not assort independently.
92
How are linked genes found experimentally?
They are found on the same chromosome and are inherited together i phenotypic ratios are not according to the Mendelian ratio.
93
What is chromosome mapping? How is gene linkage used in chromosome mapping?
The more frequently linked genes are separated, the farther apart they are on a chromosome. This provides an idea of the relative positions of genes on a chromosome, which is called gene mapping.
