Exam 2 Flashcards
Which of the following types of mutations can result in a
frameshift?
nucleotide-pair substitution in a coding region
* nucleotide-pair substitution in a noncoding
region
* 1 nucleotide-pair insertion in a coding region
* 1 nucleotide-pair insertion in a noncoding
region
* 3 nucleotide-pair insertion in a coding region
1 nucleotide-pair insertion in a coding region
What is the function of cell division?
-Development from a fertilized cell
-Growth
-Repair
What is mother Cell?
It’s when the cell divided.
What is Daughter cell?
When the cells form after the division.
What are DNA cells made of?
Genome
What are Prokaryotic cells?
A single DNA cell.
what are Eukaryotic cells?
Many number of cells.
Where are DNA molecules packaged in?
Chromosomes
What are Somatic cells?
non-reproductive cells) Have two sets of chromosomes (your skin)
What are Gametes?
Reproductive cells: sperm and eggs) have half as many chromosomes as Somatic cells.
What are Chromatin?
a complex of DNA and protein that reduces during cell division.
What is Chromatid?
is one half of a duplicated chromosome.
When are Chromatids form?
During chromosome duplication
What are Centromere?
holds the chromatids together
What are Telomeres?
repeating sequences at the ends of chromosomes that replication of the end of the chromosomes. Preservation of the end of each chromosome.
What shapes are Eukaryotic chromosomes?
linear chromosomes
What shape are Prokaryotes?
have circular DNA
Eukaryotic cell division consists of?
Mitosis, Cytokinesis, Mitotic phase, Gametes
What is Mitosis?
The division of the nucleus
What is Cytokinesis?
the division of the cytoplasm
What is Mitotic phase?
together mitosis and cytokinesis
What is meiosis?
variation of cell division. Sperm and eggs
What are the steps to the cell cycle?
-Interphase (transcription and translation happens)
-G1 (the cell grows physically and increases the volume of both protein and organelles)
-S stage ( Each of the 46 chromosomes is duplicated by the cell)
-G2 ( repairs errors)
-M phase 1 (Mitosis is division of chromosomes, genetic material)
- Cytokinesis Phase 2 (is the division of the rest of the cell )
In a diploid cell with four chromosome pairs (2n = 8), how many centromeres will be found in a nucleus at G2 of the cell division cycle?
8
What are the five phases of mitosis?
-Prophase
-Prometaphase
-Metaphase
-Anaphase
-Telophase
What is Kinetochore?
Where the microtubules attaches to the chromosomes in the centrosome.
What is happens cleavage furrows in miosis?
draws the plasma membrane toward the cell center, pinching the cytoplasm into two lobes that are subsequently separated into two cells.
what is phycoplast?
ensures that the plane of cell division passes exactly between the two daughter nuclei.
What is phragmoplast?
Formation that divides the two daughter cells.
What is binary fission?
a process by which a single cell splits into two cells to multiply
What cells use binary fission?
Prokaryotic cells
Which of the following events would be most likely to produce cells with several nuclei?
repeated mitosis without cytokinesis
Besides the ability of cancer cells to divide intensively, what else could logically result in a tumor?
lack of appropriate cell death
Name four things that you should do or avoid to do to decrease the chances for cancer development.
keeping a healthy weight, avoiding tobacco, limiting the amount of alcohol you drink, and protecting your skin.
_ are the major lipids of plasma membranes.
Phospholipids
What is Maturation promoting factor?
is the signal for chromosomes to enter mitosis and for the cell for later on to enter cytokinesis
Which of the following statements best describes what would happen if MPF (maturation-promoting factor) is introduced into immature frog oocytes that are arrested in G2?
The cells would enter mitosis.
Students in a biology lab isolated cells in various phases of the cell cycle. A population of cells that have twice the DNA of G1 phase cells was most likely isolated from which of the following part of the cell cycle?
in the G2 phase
What is Maturation promoting made of?
-Cyclins
Kinases
What does Cyclin-dependent kinase do?
When the cell goes through G1, S, G2, and M the kinase
After the cell finishes the DNA synthesis is progressing through G2, before it arrives to the check points G2 check points the cyclin is attached to it and forming a dimer
What are the signals that turn the cell cycle on?
Density-dependent inhibition
What is Heredity?
Is the transmission of recipes of traits. You get the recipe the genes from your parents on how to make the proteins.
Which of the following events occurs during telophase?
How does Prophase look like?
chromosomes become visible because the chromosomes condense.
How does Prometaphase look like?
the nuclear envelope disappears
What does Metaphase look like?
chromosomes a line on a metaphase plate/ invisible metaphase plate
What happens in Anaphase?
sister chromatids separate
What happened in Telophase?
re-formation of the nuclear envelope and cytokinesis quickly follows mitosis.
How come chromosomes can move?
they move because of Microtubules. Microtubules attached to them
What is Locus?
genes are located in the linear order on a chromosome
What is asexual reproduction?
that’s when the parental organism gives rise to next generation without contribution from the other sexual partner
What are homologous chromosomes?
identical Chromosomes from mom and dad
What is Karyotype?
is the chromosomes in order from biggest to smallest
What is Human somatic cells?
any cell other than a gamete) have 23 pairs of chromosomes
What is a diploid stage?
we got our generic material from one parent and from another parent so two copies so we are diploid.
What is haploid?
The number of chromosome we get from one parent is 23
What is autosomes?
23 chromosomes that have noting to do with your sex chromosomes
What is zygote?
The product of fertilization of that fusion
What are the Two steps for Sexual reproduction?
Meiosis
Fertilization
How meiosis reduces chromosome number?
-start with homologous chromosomes in diploid stage
- Chromosomes replicate
- sister chromatids
- Meiosis I separates
-Meiosis II sister chromatids separate
What does not happen in mitosis, but happens in Meiosis?
The two replication DNA found itself and they form a homologous pair.
What are the Stages of Meiosis?
-prophase I (When homologous chromosomes pair, they can exchange pieces of genetic material this is known as crossing over
they can exchange a pieces of genetic material between non-sister chromatids
-Metaphase I (Where homologous chromosomes align on the metaphase plate)
-Anaphase I ( We have homologous chromosomes separate. Sister chromatids remain attaches and move toward the pole
Telophase I and Cytokinesis)
- Meiosis II (without DNA replication)
-Prophase II (each still composed of two chromatids moves toward the metaphase plate)
-Metaphase II ( arranged at the metaphase plate)
-Anaphase II (the sister chromatids separate)
-Telophase II and Cytokinesis (the chromosomes arrive at the opposite poles and Nuclei form and chromosomes start decondensing)
A particular organism has 46 chromosomes in its Karyotype. Which of the following statement is correct regarding this organism?
It produces gametes with 23 chromosomes
Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal?
Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells
___we produce two cells that are genetically identical and are still diploid
Mitosis
___we produce four cells that have a haploid chromosomes number, half and they are not genetically the same to the maternal cell.
Meiosis
has PMAT
Mitosis
has PMAT twice
Meiosis
What are The origins of Genetic Variation?
- Crossing-over
- Independent Assortment
-Random Fertilization
Crossing over of chromosomes normally takes place which of the following processes?
Meiosis I
Quaking aspen trees usually reproduce by extending underground stems that then push above ground and grow into trees. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in cells of the underground stems?
38
Which of the following
contribute to variation in
offspring for sexually
reproducing organisms?
a) Independent orientation
of tetrads during
meiosis
b) Crossing over of during
tetrad formation
c) Sexual reproduction
d) All of the above
d
Homologous chromosomes _________.
a. carry the same gene sequence
– b. are a set of chromosomes that a cell
receives from one parent
– c. do not include the sex chromosomes
– d. are formed when the chromosomes
separated during anaphase
a
How and at what stage do
chromosomes undergo
independent assortment?
a) meiosis I pairing of homologs
b) anaphase I separation of homologs
c) meiosis II separation of homologs
d) meiosis I metaphase alignment
e) meiosis I telophase
d
- The diagram above
represents the cell cycle
through time of a eukaryotic
organism. Which of the four
phases of the cell cycle is the
most variable in length of time,
depending on the type of cell?
a) G1 phase
b) S phase
c) G2 phase
d) M phase
a
Which of the following events occurs during Metaphase?
-a. chromosomes line up on the midline of the cell
– b. nucleoli reappear
– c. the mitotic spindle begins to form
– d. cytokinesis
a
Which of the following events occurs during prophase?
-a. chromosomes line up on the midline of the cell
– b. nucleoli reappear
– c. the mitotic spindle begins to form
– d. cytokinesis
c
Which of the following events occurs during anaphase?
– a. chromosomes align on the midline of the cell
– b. the cleavage furrow forms
– c. tetrads form
– d. centromeres divide
b
Which of the following events occurs during telophase?
– a. chromosomes line up on the midline of the cell
– b. nucleoli reappear
– c. the mitotic spindle begins to form
– d. cytokinesis
b
Which of the following events occurs during Prophase I of meiosis?
– a. chromosomes align on the midline of the cell
– b. the cleavage furrow forms
– c. tetrads form
– d. centromeres divide
c
Which of the following events occurs during anaphase II ?
– a. chromosomes align on the midline of the cell
– b. the cleavage furrow forms
– c. tetrads form
– d. centromeres divide
d
A duplicated chromosome consists of two
sister______
– a. centromeres
– b. centrosomes
– c. chromatids
– d. chromatins
c.
What did Greg Mendel do?
he hypothesized that there has to be a unit that determines inheritance and that this is passed from generation to generation
What is Hybridization?
the process of mating the individuals that go in the cross are parents.
What is Alternative versions?
account for variations in inherited characters
What is locus?
Each gene is place in the specific place on the chromosome
What is alleles?
one of two or more versions of DNA sequence (a single base or a segment of bases) at a given genomic location
What is homozygous?
having inherited the same versions (alleles) of a genomic marker from each biological parent.
What is genotype?
The description of the genetic material
What is phenotype?
This genes code for proteins that define the physical appearance of an organism
Where do Homologous chromosomes come from?
come from your parents one from mom and one from dad so we have two alleles for each gene
What is Hybrid?
offspring of two different varieties
What is Heterozygous?
When an organism has different alleles for a gene.
What is Dominant alleles?
gene always expressed even if heterozygous
What is allelic interactions?
This gene interaction occurs between the alleles of a single gene.
What is Phenotype?
physical appearance
What is Genotype?
generic makeup
what is One locus?
To tell us where on a chromosome a specific gene is.
what is Multiple loci?
is the set of genes at more than one locus which is inherited by an individual from one of its parents.
How would you know an individual is homozygous recessive if you can see it the trayed that makes them homozygous?
We always testcross with a homozygous recessive
What did Mendel discover two laws for classical genetics
- Law of segregation
- Independent assortment
What is complete dominance?
strong covers the recessive allele
What is Hypercholesterolemia?
mode of inheritance (also known in human genetics)
What is Multiple Alleles?
the situation where we have more than two alleles in a population
why is immunoglobulin A and immunoglobulin B shown in capital letters?
they are both dominant
what is Third extension of Mendel’s rule?
codominance
What an example of codominance?
when both alleles are expressed
With blood type we can have 6 number of genotypes
-I can have homozygous dominant for immunoglobulin A
- I can have homozygote dominant for immunoglobulin B
- AB blood is heterozygous dominant
What is the Fourth extension of Mendel’s law?
pleiotropy
What is pleiotropy?
when I still have a single gene, but that gene affects many traits
What is Polygenic trait?
when I have multiple genes affecting one trait
What is Epistasis?
a gene at one locus alters the phenotypic expression of a gene as a second locus.
What is the 6th extension of Mendel’s law?
Role in Environmental impact on Phenotype
Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes eye problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information?
It is pleiotropic.
What is the genotype of an individual
who is heterozygous for dimples?
– a. DD
– b. dd
– c. Dd
– d. dimples
C
What is Genetic map?
an ordered list of the genetic loci along a particular chromosome
A recombination frequency of 50% indicates____________.
the two genes are likely to be located on different chromosomes
A homozygous tomato plant with red fruit and yellow flowers was crossed with a homozygous tomato plant with golden fruit and white flowers. The F1 had red fruit and yellow flowers. F1 plants were testcrossed (crossing them to homozygous recessive individuals), and the following offspring were obtained: Red fruit and yellow flowers–41 Red fruit and white flowers–7 Golden fruit and yellow flowers–8 Golden fruit and white flowers–44 How many map units separate these genes?
15
What is Point mutations?
are chemical changes in just one base pair of a gene. That one point on a chromosome is one nucleotide
Mutations are changes in the nucleotide sequence of DNA that ____.
can be passed on to daughter cells
Common form of skin cancer
Is when the double T bond that can be trigger by the boost of energy coming from UV light/ tanning booths
what is Monosomic zygote
one chromosome less
What is Trismic?
one chromosome more
In humans Aneuploidy is survivable in chromosome __________
21
What are Klinefelter syndrome sex chromosomes?
Aneuploidy of the sex chromosomes involving XXY
What are Turner syndrome sex chromosomes?
Aneuploidy XO
Klinefelter syndrome and trisomy are examples of_____
Aneuploidy disorders involving sex chromosomes
What is Polyploidy?
an organism has more than two complete sets of chromosomes. Entire genome
What is Triploidy
3n three sets of chromosomes
what is Tetraploid
4n four set of chromosomes
What is Deletion?
removes a chromosomal segment
What is Duplication?
repeats a segment
What is Inversion?
reverses a segment within a chromosome
What is Translocation?
moves a segment from one chromosome to another
Why would translocation happen?
our DNA is made of four nucleotides. The sequences can repeat and then we can have some kind of pending because the sequences would seem to have homology
What is the map unit?
One map unit 1 centimorgan represents 1% of recombination frequency
Who constructed the first genetic map?
Alfred
A recombination frequency of 50% indicates____________.
the two genes are likely to be located on different chromosomes
Barbara McClintock provided the first proof for the chromosomal theory of inheritance, with_____
her corn work
Steps of chromosomal theory of inheritance acceptance
- First Thomas Morgan
- Alfred Sturtevant
-Barbara McClintock
- Alfred Sturtevant
What is Non-disjunction?
is the lack of separation of either homologous pair or sister chromatids
we have non-disjunction in meiosis I then we end up __________
with 2 gametes having extra chromosome and 2 gametes having one chromosome less
When we have non-disjunction between sister chromatids occurring in meiosis II we have__________
one garment that has an extra chromosome and one gamete that has a missing chromosome
What does trisomy number mean?
I have three chromosomes instead of two for one pair
Example of Trisomy 21
Down Syndrome
If cell Q enters meiosis, and nondisjunction of one chromosome occurs in one of its daughter cells during meiosis II, how will this affect the gametes at the completion of meiosis?
One-quarter of the gametes descended from cell Q will be n + 1, one-quarter will be n - 1, and half will be n.
What is frame shift?
If I have base-pair either insertion or deletion.
When a mutation caused by a nucleotide-pair insertion
occurs in a protein-coding region, which of the following
types of mutations cannot occur?
* silent
* frameshift
* missense
* nonsense
* none of the above
silent
What is Sickle cell anemia traits?
is autosomal recessive single trait
What is Albinism traits?
Autosomal recessive
What is cystic fibrosis traits?
autosomal recessive
what is Phenylketonuria (PKU)
autosomal recessive
What is Tay-Sachs disease
autosomal recessive
What is Achondroplasia
dwarfism, autosomal dominant
what is Alzheimer’s disease (one type)
Autosomal dominant
Huntington’s disease
autosomal dominant
Hemophilia
x-linked recessive
Duchenne muscular dystrophy
x-linked recessive
colorblind
x-linked recessive
down syndrome
aneuploid condition that results from three copies of chromosome 21
Trisomy X
Aneuploidy of the sex chromosomes involving Karyotype XXX
Waardenburg syndrome
autosomal dominant
In the pedigree what does a circle mean?
Female
n the pedigree what does a square mean?
male
What does a dark square mean?
Affected male
What does a dark circle mean?
Affected female
dot inside circle mean?
x-link recessive
Almost all cases of cystic fibrosis, a(n) ____ genetic disorder, are the result of mating between two unaffected parents.
Sex Linked Genes
Rank the following one-base point mutations with respect to
their likelihood of affecting the structure of the corresponding
polypeptide (from most likely to least likely).
1: insertion mutation deep within an intron
2: substitution mutation at the third position of a codon in an exon
3: substitution mutation at the second position of a codon in an
exon
4: deletion mutation within the first exon of the gene
A. 1, 2, 3, 4
B. 4, 3, 2, 1
C. 2, 1, 4, 3
D. 3, 1, 4, 2
E. 4, 1, 2, 3
B
