Chapter 8 Flashcards
double stranded helical nucleic acid,
DNA
unit of hereditary information consisting of a specific nucleotide sequence
gene
carrying structure containing DNA and proteins
Chromosome
the noncondensed form of DNA and proteins present when the cell is not dividing
Chromatin
Is binary fission an example of sexual or asexual reproduction?
Asexual
How many chromosomes do bacterial cells have?
1
A single-celled eukaryote, like an amoeba, would reproduce by ___________.
binary fission
Are the two cells resulting from binary fission genetically identical or unique?
identical
Organisms that are the result of sexual reproduction have a pair of chromosomes, one from each parent. A human somatic (body) cell has 46 chromosomes. How many chromosomes are inherited from each parent?
23
In humans, a sperm cell would have _____ chromosomes
23
The body cell of a dog has 78 chromosomes. How many chromosomes are in a dog egg cell?
39
T/F The number of chromosomes correlates to the complexity of the organism. For example, a complex organism like a human will always have more chromosomes than a ‘lower’ organism like a tree.
FALSE
How many chromosomes are found in a human zygote?
46
In humans, a cell from the liver would have _____ chromosomes.
46
Most organelles duplicate during the ___ phase in order to prepare for becoming two separate cells, both of which will need a set of organelles.
G1 phase
How many chromosomes are present during the G1 phase in humans?
46
Which two organelles duplicate themselves independently and separately from the rest of the cell cycle?
mitochondria and chloroplast
How many chromatids are present during the S phase in humans?
92
Based on the illustration of the cell cycle, the cell spends most of its time in which phase?
interphase
If the chromosomes were to not line up in metaphase, would each new daughter cell have the correct number of chromosomes?
no
What would happen if the spindles did not attach to each chromosome?
the chromatids may fail to separate
Choose the purposes of mitosis:
Growth
Gamete formation
cell replacement
asexual reproduction
Growth, asexual reproduction, cell replacement
Which of the following types of animal cells would you expect to have a fast (frequent) rate of mitosis?
skin
A fish embryo would have a _____ rate of cell division.
fast
Which of the following disappear during telophase?
Nuclear envelope
Mitotic spindle
Nucleolus
mitotic spindle
The imaginary line where the chromosomes line up in the center of the cell is called the _______________.
Mitosis plate
metaphase plate
middle plate
mitochondria plate
Metaphase plante
Which of the following reform during telophase?
nuclear envelope
mitotic spindle
Centrosomes
Nuclear envelope
Which of the following has disapeared by the end of prometaphase?
mitotic spindle
sister chromatids
centromere
nuclear envelope
centrosome
Nuclear envelope
Cytokinesis overlaps with which two phases of the cell cycle?
Anaphase and telophase
Are daughter cells resulting from mitosis genetically unique or identical?
Identical
In humans, how many chromosomes are in each daughter cell following mitosis?
46
Which phase of the cell cycle is the longest?
interphase
How would mutations on a gene controlling the G2 checkpoint contribute to the formation of a cancer?
It would allow cells with inaccurate DNA replication to divide.
If there is abnormal growth of cells that never leaves the original tissue and has well-definied edges, it is classified as a ____________________ tumor.
benign
You look into a microscope and see cells that growing together so each cell is touching another cell or surface. You then notice that the cells are continuing to grow on top of eachother. You would conclude that this may be a mutation in the genes that signal for (control of):
contact inhibition
If the cells of a tumor break off and travel to a different part of the body and begin a tumor in the new location the cancer is said to
have metastisized
A cell has a diploid (2n) number of 4. How many chromosomes will be present in each of the resulting haploid (n) cells?
2
If a wombat has 40 chromosomes, how many chromosomes must be in each egg/sperm to ensure that the offspring will have the correct number of chromosomes?
20
In humans, which sex chromosomes would genetically denote a female?
XX
Homologous chromosomes are _______ to each other.
Similar
T/F? Even though they carry different genes, sex chromosomes behave as a __________________.
homologous pair
In which phase is DNA duplicated?
S Phase of Interphase
Sister chromatids align at the center of the cell.
Metaphase II
Tetrads separate, resulting in haploid cells
Anaphase I
Sister chromatids separate
Anaphase II
Tetrads align along the equator of the cell
Metaphase I
Occurs in body cells, such as skin, liver, and bone
Mitosis
Crossing over
Prophase I
4 separate cells form that are genetically unique
Telophase II/Cytokinesis
DNA duplicates
Interphase
Occurs in the ovaries and testes of animals
Meiosis
During which phase of meiosis are the sister chromatids separated?
Anaphase II
During which phase of meiosis are the homologous chromosome pairs separated?
Anaphase I
In humans, how many chromosomes does each daughter cell have after MEIOSIS II?
23
In humans, how many chromosomes does each daughter cell have after MEIOSIS I?
23
In humans, how many chromosomes does each daughter cell have after MITOSIS?
46
Which of the following contribute to genetic variation?
crossing over
independent orientation
mutation
mitosis
binary fission
random fertilization
Crossing over, independent orientation, random fertilization, mutation
Match:
XXX
Trisomy 21
XO
XXY
————-
Down’s syndrome
“Metafemale”
Turner’s syndrome
Klinefelter’s syndrome
XXX: Metafemale
Trisomy 21: Downs
XO: Turners
XXY: Klinefelters
Which of the following disorders involve autosomes?
Down’s syndrome
Which of the following would be easiest to view under a microscope?
chromosomes
Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?
In the centrosomes.
Organisms produced as a result of binary fission exhibit ______ genetic variation.
no
During which phase(s) of mitosis do we find chromosomes composed of two chromatids (duplicated chromosome)?
from G2 of interphase through metaphase
All of the following occur during mitosis except:
the formation of a spindle.
the condensing of chromosomes.
the disappearance of the nucleolus.
the uncoupling of chromatids at the centromere.
the synthesis of DNA.
Synthesis of dna
Which of the following does not occur during mitosis?
packaging of the chromosomes
replication of the DNA
spindle formation
separation of the centrosomes
separation of sister chromatids
Replication of DNA
The genetic material is duplicated during
S phase
The haploid (n) number of chromosomes is found in nearly ______ cells of humans and most other animals.
sex cells
The genetic material is duplicated during
the mitotic phase.
mitosis.
G2
G1
the S phase.
The S Phase
Organisms produced as a result of binary fission exhibit ______ genetic variation
no
A microtubule organizing center (__________) is located at _________ of the dividing cell in both plants and animals.
centrosome
each pole
Viruses and chemical exposure can cause mutations in ___________ which can lead to cancer.
proto-oncogenes
In some organisms, mitosis occurs without cytokinesis occurring. This will result in what?
A cell having more than one nucleus.
Which of the following organisms does not use mitosis to make another cell?
mushroom
banana tree
bacterium
cow
cockroach
Bacteria
How do the daughter cells at the end of mitosis compare with their parent cell when it was in G1 of the cell cycle?
The daughter cells have the same number of chromosomes and the same amount of DNA.
One difference between a cancer cell and a normal cell is that:
Cancer cells continue to divide even beyond their boundaries.
During which phase(s) of mitosis do we find chromosomes composed of two chromatids (duplicated chromosome)?
from G2 of interphase through metaphase
T/F? Binary fission uses a spindle (network of microtubules made by centrosomes) for the separation of daughter chromosomes, just as in mitosis.
FALSE
DNA replication occurs in the ____ stage of interphase just before _______.
last; mitosis
Contact inhibition stops normal cells from dividing when they ___________, but this is not functional in cancer cells.
come in contact with neighboring cells
DNA replication occurs in the _____ stage of ________ just before mitosis.
last stage of interphase
A ____________ ___________ ___________(centrosome) is located at each pole of the dividing cell in both _______ and _______
microtubule organizing center
both plants and animals.
How many individuals are required in asexual reproduction?
1 individual
Cell division in eukaryotes involves separate processes called __________ and __________
mitosis and cytokinesis
The centromere is a region in which:
chromatids of a duplicated chromosome are attached to one another and where the DNA is pinched in a bit.
Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?
Centrosomere
T/F The haploid (n) number of chromosomes is found in nearly all body cells of humans and most other animals
FALSE
Chromosomes are aligned along the cell’s equator during ___.
The metaphase
T/F Binary fission uses a spindle (network of microtubules made by centrosomes) for the separation of daughter chromosomes, just as in mitosis.
FALSE
Brain cells (neurons) are constantly in _____ phase of interphase. This means that they _______ able to regenerate after injury.
G0
are not able to regenerate
A particular cell has not replicated its DNA yet. The cell in question is most likely in
G1
_______________ stops normal cells from dividing when they come in contact with neighboring cells, but this is not functional in ______ cells
Contact inhibition, cancer cells
In anaphase II of meiosis the ________ are split, breaking the _________.
chromatids
Centromere
T/FSources of genetic variation in a sexually reproduction arises only from fertilization.
FALSE
Another name for a tetrad is a ______.
bivalent
Spindle fibers connect to the ______ fibers meiosis.
Kinetochore
Crossing over occurs during ____________
Prophase I.
t/f Meiosis leads to gametogenesis, oogenesis, and spermatogenesis.
TRUE
T/F? The centromere holds the homologous chromosomes together in meiosis II.
FALSE, the centromere is broken
T/F DNA is replicated between meiosis I and meiosis II.
FALSE, S phase of Interphase
The chromosome ______ are located at the metaphase plate during metaphase I.
tetrads
A failure of meiosis can lead to ____ number of genes in a gamete and therefore inviable gametes.
Increased
T/F the centromere holds the ______________ together in meiosis II.
sister chromatids
T/F The events of meiosis II are most similar to interphase.
FALSE
Each gamete contains _____ sex chromosome(s)
1
In meiosis, chromosomes are aligned in the center of the cell by ___________
spindle fibers.
Alignment of the chromosomes during metaphase I leads to _____________________
variation of genetic material.
T/F? At the end of meiosis II, the chromosomes consist of sister chromatids held together at a centromere.
FALSE
The microtubule spindle apparatus originates from the _________
centrosomes
There is/are ______ division(s) in meiosis.
2
_______ are arranged along the equator during metaphase I
Tetrads
T/F? Meiosis leads to gametogenesis, oogenesis, and spermatogenesis.
TRUE
The replication of DNA and the duplication of genes occurs during _______
S phase of Interphase
In meiosis the daughter cells are genetically ___.
Different
T/F? The microtubule spindle apparatus originates from the plasma membrane.
FALSE
In anaphase II of meiosis the ___________ are split, breaking the ____________
chromatids, centromere
During anaphase I the association between members of a tetrad is _______and they ________.
disrupted, seperate
The cell formed through fertilization is called a _______.
zygote
T/F Homologous chromosomes are similar in size, similar in shape and location of the centromere, and carry the genetic code for the same traits.
TRUE
Homologue separation occurs during ________of meiosis.
anaphase I
The ___________ holds the sister chromatids together in meiosis I.
centromere
If DNA replication has already occurred, the chromosomes consist of ____________ held together at a centromere.
sister chromatids
If there is any damage to the DNA the cell will try to repair the damage before allowing the cell to continue to the _______ of the cell cycle
S phase
If a sperm contains 4 chromosomes, it comes from an animal that has __ chromosomes
8
If DNA replication has already occurred, the chromosomes consist of sister chromatids held together at a __________.
centromere
Does asexual reproduction create genetically identical or adverse offspring?
Identical
Does sexual reproduction create genetically identical or adverse offspring?
Diverse
When is asexual reproduction beneficial?
You don’t need a mate, it takes less time and energy.
How is asexual reproduction bad?
More competition for resources and stable environment and no genetic diversity.
What are three benefits of sexual reproduction?
Having genetic diversity, having genes to adapt, evolution occurs easier.
What are some organisms that do asexual reproduction?
Bacteria, yeast, liver cells, starfish.
What are chromosomes?
Condensed DNA when cell is dividing.
What is chromatin?
Loose DNA when cell is not dividing.
What is a gene?
A unit of heredity found on a certain place on a chromosome that codes for a certain product.
What is DNA?
Your genetic blueprint.
What are chromosomes, chromatin, and genes made of?
DNA and proteins.
Where may they be found in the cell?
Nucleolus.
How many chromosomes are found in a human body cell? How many strands of chromosomes?
46 chromosomes, 92 strands.
How many genes can be found in a human cell?
Thousands
What isthe information in genes used for?
Making proteins and enzymes, growth and development of a cell, protecting the organism from infection, and ensuring fidelity of offspring to the parent.
Where do diploid cells come from?
2 haploid cells
What are somatic cells?
Body cells
Are somatic cells haploid or diploid?
Diploid
What is the notation for diploid?
2n
What are gametes?
Sex cells
Are gametes haploid or diploid?
Haploid
What is the notation for haploid?
1n
What does n stand for?
Number of chromosomes