test 4 Flashcards
chapters 10 - 12
1
Q
What is a Complete Set of Genetic Material/DNA in an Organisms Called
A
Genome
2
Q
How Many Total Chromosomes
Do Humans Have?
A
46 - 23 sets
3
Q
When it comes to DNA, Every
Somatic Cell in the Body has
A
The exact same set of DNA
4
Q
Every Time a Cell Divides to
Create a New Cell, it Needs to
____________ it’s DNA
A
Replicate
5
Q
What Do We call a Substance
that Can Cause Cancer?
A
Carcinogen
6
Q
What is BRCA Genes
A
Genes that encode proteins that are important for repairing damaged DNA
(Inheriting a mutation in BRCA1 or BRCA 2 significantly increases chance of developing cancer)
7
Q
When it comes to Proteins, Cells
in the Body Express ___________
A
Different Proteins – Resulting in
Different Structures and Functions
8
Q
Define Tissue
A
a group of cells working together to carry out a specific function
9
Q
Define Cell Division
A
Process by which a cell reproduces itself
10
Q
Embryonic Development
A
Growth and development
* One fertilized egg cell and its daughter cells continuously divides to create trillions of cells
11
Q
Cell division is important for
A
- embryonic development
- cell replacement
- wound Healing
12
Q
Replaces dying cells and maintains healthy tissues
(Most cells have a finite lifespan)
A
Cell Replacement
13
Q
cell cycle
A
Ordered sequence of events
- one parent cell_two identical daughter cell
14
Q
preparatory phase
* Makes copy of its contents
* New cell has the same amount of organelles, DNA, and cytoplasm as the original cell
A
Interphase
15
Q
division phase
* One parent cell divides into two new daughter cells
* Each of which is identical to the parent cell
A
Mitotic Phase
16
Q
What happens in the Interphase - Preparation
A
Cells spend most of their time in interphase. Divided into three sub-phases: G1, S, and G2
17
Q
What happens in the Interphase – G1 phase
A
- The cell enlarges, produces additional cytoplasm, and begins to produce new organelles
- Chromosomes are loosely gathered in the nucleus
18
Q
What happens in the Interphase - S phase
A
DNA replication occurs, each chromosome is replicated to produce two sister chromatids
19
Q
DNA replication results in
A
- Two DNA molecules with one original strand and one new strand
- Semi-conservative replication
20
Q
The two identical DNA molecules that make up a replicated chromosome following DNA replication are called
A
sister chromatids
21
Q
Define Centromere
A
The specialized region of a chromosome where the sister chromatids are joined
* Critical for proper alignment during mitosis
22
Q
What happens in the Interphase – G2 phase
A
- Cell continues to grow
- Prepares and produces molecules needed for cell
division
23
Q
In drawings of chromosomes, the “X” shape indicates that
A. the DNA has been replicated.
B. two sister chromatids exist.
C. cell division hasn’t yet occurred.
D. the cell is probably ready for mitosis.
E. All of the above.
A
E. All of the above
24
Q
Mitosis is
A
nuclear division that is a Separation of sister chromatids
* Each cell will only have one chromatid for each chromosome
25
what happens in the prophase stage?
Replicated chromosomes begin to coil (becoming visible under microscope) and Nuclear envelope begins to disassemble
26
what are centrioles and what do they do in the prophase stage?
are cytoskeleton component and migrate to opposite poles of cell
* Form protein fibers of the mitotic spindle
27
What is Mitotic spindle?
a structure that separates sister chromatids during mitosis; Made of microtubules (spindle fibers)
28
what is used to attach to centromere of replicated chromosome?
kinetochore
29
what happens in the Metaphase?
* Spindle fibers from opposite ends (poles) attach to the sister chromatids via kinetochore of each chromosome
* Replicated chromosomes become align along the middle of the cell (equator)
30
What happens in the anaphase?
* Spindle fibers shorten and pull sister chromatids to opposite ends of the cell
* Sister chromatids now considered individual chromosomes
31
What happens in the telophase?
* Identical set of chromosomes reaches each pole
* Spindle fibers dissemble
* Nuclear membrane begins to form around each set of
chromosomes
32
What is cytokinesis and what happens during it?
the division of the cytoplasm. It divides cell into two daughter cells, each containing a full complement of organelles and DNA in nucleus
* Can begin to occur during mitosis
33
During mitosis sister chromatids are:
held together by the centromere.
34
what structure is formed in plant and animal cells during cytokinesis?
Animal cells - cleavage furrow (cell membrane pinches)
plant cells - cell plate (new cell wall)
35
What's cell cycle checkpoints?
ensures stages of cell cycle are completed correctly and prevents cell from progressing to next stage until accurately finished with current stage.
36
what's growth factors?
molecules that signal a cell to divide when appropriate
37
what happens when a cell has irreparable damage at the checkpoint?
Apoptosis occurs
38
What is apoptosis
Programmed cell death and prevents damaged cell from further replicating.
39
Cell cycle checkpoints involve
proteins
40
How are proteins made
Gene Expression
41
Proto-oncogene
genes that produce proteins that
* Provide signals that lead to cell division
* Accelerate growth
42
Tumor suppressor genes
genes that produce proteins that
* Slow down cell division
* Repair DNA mistakes
* Trigger apoptosis
43
What is Cancer?
a disease of unregulated cell division that Leads to Mistakes in DNA replication and Mistakes during mitosis
44
What happens when a gene is mutated
- May result in protein with altered function or nonfunctional protein
- Mutations can also affect regulatory region
45
Mutations that affect _____ &_____ resulting in non-functional cell cycle proteins.
proto-oncogenes
tumor suppressor genes
46
When a proto-oncogene is mutated and becomes overactive, it is called an
oncogene
47
in mutation of tumor suppressor genes checkpoints
there is no control and bad cells continue to live
48
For cells to become cancerous...
* Multiple mutations in several genes that regulate cell cycle
* Combination of both tumor
suppressor and proto-oncogenes
49
Multi-hit model
* Multiple mutations arising over time
1. Inherited from parents
* Germ-line mutations
2. Errors in DNA replication
* Increase as we age
3. Environmental insults
* Can cause errors in DNA replication
50
Benign tumor
Noncancerous tumor forms first
* Does not spread throughout body
51
Malignant tumor
Cancerous tumor then may develop
* Spread and invade other tissues (metastasize)
52
Malignancy occurs when cells
* Loss of contact inhibition and anchorage dependence
* Increase of angiogenesis
53
contact inhibition
Healthy cells stops dividing once they come into contact with neighboring cells
54
anchorage dependence
Healthy cells normally need physical contact with other cells in tissue
55
angiogenesis
Cancer cells promote growth of new blood vessels
56
ways to Fighting Cancer
* Conventional Treatment
* Surgery
* Radiation
* Chemotherapy
* Targeted Therapies
* Immunotherapy
57
People who have inherited________ start life with at least one
cancer-predisposing mutation
high-risk
mutations
58
Sporadic cancer
caused by non- inherited (acquired) mutations
59
If a cell has 20 DNA molecules during G1 phase, how many DNA molecules will the cell have in G2 phase?
40 DNA Molecules - as replication has occurred during S phase
60
A normally functioning gene that regulates the cell cycle by producing a protein that promotes cell division is most likely a:
Proto-oncogene
61
Cystic Fibrosis is caused by
a single deletion mutation
(CTT) in CFTR gene
62
What is Cystic Fibrosis (CF)
A Genetic disease where Mucus build-up blocks airways in lungs, passageways of digestive enzymes, and sweat glands
63
Diploid organism
have two copies of every chromosome
* Often written as 2n
* Where n is the number of unique chromosomes in a species
64
One copy of chromosome is inherited
from mother and the other copy from father
65
Paired chromosomes are called
homologous chromosomes
66
Homologous chromosomes can carry different
alleles of the same gene
67
Humans have 23 pairs of homologous chromosomes, but males only have
22 true pairs of homologous
chromosomes
68
Sexual Reproduction
Results in fertilization
* Leads to combination of maternal and paternal alleles in offspring
69
Gametes are
specialized reproductive cells that carry only one copy of each chromosome (haploid cells 1n)
70
haploid cells (1n)
Only one copy of unique chromosome
71
Sperm are
male gametes
72
Eggs are
female gametes
73
Embryo
An early stage of development reached when a zygote undergoes mitosis to form a multicellular
structure
74
How many total chromosomes does its somatic cells have
6 - diploid
75
How many total chromosomes does its gametes have
3 - haploid
76
To become haploid, gametes go through
meiosis - A specialized type of nuclear division that generates
genetically unique haploid gametes
77
Meiosis requires 2 rounds of divisions ......
* Meiosis I
* Meiosis II
78
What happens in meiosis I
* Separates homologous chromosomes
* Results in 2 haploid (1n) daughter cells
* Chromosome is still in replicated state (sister chromatids)
79
What happens in Meiosis II
* Separates sister chromatids
* Results in four haploid (1n) daughter cells
* Chromosomes no longer replicated
80
Principle (law) of segregation
during the production of gametes two copies of the same gene separate
81
what are the two major events during meiosis I, that no two gametes are identical
* Independent assortment
* Recombination
82
Principle (law) of independent assortment
Alleles of different genes are distributed independently of one another during meiosis
83
what happens in independent Assortment?
Maternal and paternal chromosomes randomly line up next to each other along the midline of the cell
* Separate according to how they have randomly lined up
84
what happens in Recombination
Maternal and paternal chromosomes pair and physically
exchange DNA segments
85
Chiasma
point at which paired chromosomes remain in contact during meiosis I
86
Due to recombination
Maternal chromosomes contain segments from paternal chromosomes and vice versa
87
For recessive traits People with normal phenotypes can still
pass CF allele to offspring are called
carriers
87
A person’s phenotype includes
the visible or measurable features of an individual
88
Recombination occurs when homologous chromosome pairs are close together during:
Meiosis I
88
Gregor Mendel
Father of genetics
89
A person’s genotype is
the particular genetic makeup
of an individual
90
An organism’s _________ determines its __________.
genotype; phenotype
90
Genotypes and Resulting Phenotype
* Homozygous Recessive (aa) – phenotype recessive
* Heterozygous (Aa) – phenotype dominant
* Homozygous Dominant (AA) – phenotype dominant
91
Steps for a Monohybrid Punnett
Square
1. Write down the genotypes of both parents
2. Write down the possible gametes each parent can make
3. Create an empty Punnett square and place possible gametes on the outside of the grid
4. Fill grid with possible genotypes of offspring by combining the alleles of the gametes
5. Determine the relative proportions of genotypes and phenotypes of the offspring
92
what's a Punnett square
Diagram used to determine the probabilities of offspring having particular genotypes, given the genotypes of the parents
93
22 pairs of Homologous chromosomes are autosomes. What is an autosome?
Paired chromosomes present in both males and females
94
1 pair of Homologous chromosomes are sex chromosomes. What is a sex chromosome?
Chromosomes that differ between males and females
95
X chromosomes
both men and women carry a X sex chromosome
96
If you carry 2 X chromosomes
(XX) your are considered
female
97
If you carry 1 X chromosome and 1Y chromosome (XY) your
are considered
male
98
Y chromosome
Signals the male developmental pathway
99
Sex hormones produced by
gonads (sex organs)
100
Ovaries
in females
101
Testes
in males
102
Androgens
sex
hormones
103
Testosterone
male
104
Estrogen
female
105
SRY (sex- determining region)
gene on
Y chromosome signals testes to develop
106
Recessive allele
An allele that reveals itself in the phenotype only if dominant allele is not present
107
X-linked trait
Phenotype that is determined by an allele on an X chromosome
108
Y chromosomes rarely undergoes genetic
recombination
109
Y-chromosome analysis
Comparing sequences on the Y chromosome to examine paternity and paternal ancestry
110
Short tandem repeats
(STRs) on the Y chromosome can
show that two men have the same Y chromosome
111
Incomplete Dominance
Inheritance in which heterozygotes have a phenotype that is intermediate between homozygous dominant and homozygous recessive
112
Codominance
Inheritance in which both alleles contribute equally to the phenotype
113
Rh factor
Positive Rh factor allele (Rh+) is dominant over the recessive Rh factor allele (Rh-)
114
Polygenic Trait
A single trait whose phenotype is determined by the interaction between alleles of more than one gene
115
Multifactorial Inheritance
An interactions between genes and environment contributes to a phenotype or trait
116
Nondisjunction
Failure of chromosomes to
separate accurately
117
Aneuploidy
An abnormal number of one or
more chromosomes
118
Trisomy 21
Down syndrome, results when an embryo inherits an extra copy of chromosome 21
119
Fetal karyotype
The chromosomal makeup of cells
