Mitosis Flashcards
Examples of Asexual reproduction
Budding, vegetative reproduction, binary fission, spores, fragmentation, parthenogenesis
Clones /Genes from one parent (does not require fertilization by a male)
Asexual reproduction
Offspring arise from parents and inherit genes from both parents
Sexual reproduction
A complex of DNA and proteins that forms chromosomes in the nucleus of a cell
Chromatin
Gene expression, genome stability and chromosome segregation,”junk DNA”
Heterochromatin
Expressed “true” DNA by building a protein (loosely packed)
Euchromatin
140 million long, deoxyribose and phosphate group
Nucleotide
Basic unit of DNA packaging in eukaryotes, cube shape, promotes and guides coiling of DNA, wound around eight histone proteins
Nucleosomes
Complete set of genes or DNA in an organism (23 pairs)
Genome
Two sets of chromosomes with one set inherited from each parent
Diploid
One set of chromosomes in an egg or sperm cells
Haploid
22 cells within cells, chromosomes that are not asexual chromosome
Autosome
22 + 1 sex chromosome, X or Y, determine sex of individual
Sex chromosome
Germ cell and not a reproductive cell
Somatic cell
Develops into a reproductive cell, egg in a female and sperm in a male
Germ cell
Reproductive cell of an animal or plant and egg or sperm cells
Gamete
Chromosome number in human somatic cells (diploid)
46 (each somatic cell contain 23 pairs of chromosomes)
XX
Female
XY
Male
Chromosome number in human gametes (haploid)
23 (contain half the number of chromosomes as a normal body cell)
Number and appearance of chromosomes, used to identify abnormalities in chromosome count with a cell; (1 to 22 Autosomes; homologous pairs)
Karyotype
“pair”; share same length, staining qualities, same genes and same location
Homologous chromosomes
Do not contain similar genetic info to each other
Non-homologist chromosomes
Get pulled apart at telophase
Sister chromatids
Barrier that protects DNA, protect end of chromosomes from deteriorating/end caps (ttaggg)
Telomeres
Hayflick limit
’60s cell divisions before chromosomes die
Terminal transferase, builds telomeres, AIDS TTAGG to end of chromosome, active in stem and cancer cells (enzyme)
Telomerase
Region where two sister chromatids are attached to each other
Centromere
Protein complex that assembles on centromere of a chromosome during cell division
Kinetochore
Interface stages
G0, G1, G2
Cell grows double in size, cell functions normally
G1 (gap 1)
Cells don’t divide often or ever
G0 (gap 0)
Cell resumes normal activity, growth and preparation for division
G2 (gap 2)
Synthesises new DNA, creating sister chromatids converted at centromere
Synthesis
Mitosis stages
PMAT- prophase, metaphase, anaphase, telophase
First stage of mitosis, parent cells duplicated DNA separate into two identical daughter cells, chromosomes are condensed, microtubules that move, nuclear envelope breaks up
Prophase
Attached to chromosomes and kinetochore- what pulls the sister chromatids apart
Spindle fibers
When chromosomes condense and lineup in center of dividing cell
Metaphase
Final stage of cell division in mitosis or meiosis, when chromosomes uncoil and new nuclei form
Telophase II
Cell movement, cytoplasmic division of the cell at end of mitosis resulting in two daughter cells
Cytokinesis
Cell decides to duplicate DNA and divide, primary point for external signal influence
G1/s checkpoint
Makes a commitment to mitosis, assesses success of DNA replication
G2/m checkpoint
Cell insures all chromosomes are attached to spindle
Late metaphase (spindle) checkpoint
Inhibits mitosis/gene responsible for cell cycle regulation; The slowing down process to repair DNA or signal cell death.
Tumor suppressor genes - apoptosis
Abnormal P53, cell division of abnormal cells
Cancer
Spread of cancer cells two other areas of the body
Metastasis
Most common skin cancer, least dangerous because it rarely merastasizes; can cause significant destruction and disfigurement by invading surrounding tissues; considered malignant
Basal cell carcinoma
Most dangerous skin cancer, fast acting, malignant tumor, less common
Melanoma
White blood cells that destroy infected and disease cells
Natural killer cells
Advantages for Asexual reproduction
Known for its rapid population growth and only requires one parent
Disadvantages of Asexual reproduction
It lacks genetic diversity making population vulnerable to environmental changes
Advantages of Sexual reproduction
Provides genetic variation and allows for better adaptation to changing environments
Disadvantages for Sexual reproduction
It requires finding a mate and takes longer to produce offspring
Nuclear division, replicating two identical daughter cells for growth and repair
Mitosis
Females can reproduce without a male (lizards, plants, sharks)
Parthenogenis
Reproduce chromosome number by half to create four haploid cells, gamate production and reproduction of the organism
Meiosis
Contains chromatin, surrounded by nuclear envelope
Nucleus
Brain cells
Neurons (> 100 years lifespan)
50 days lifespan
Skin cells
Cells lining the alimentary canal
Gut (5-day lifespan/shortest lifespan)
Skeletal cells
Bone cells (10 year lifespan)
Intercostal skeletal
Muscles (15 year lifespan)
Red blood cells lifespan
120 days
Cardio myocytes
Heart muscle cells (>50 year lifespan)
Ordered series of events involving cell growth and division that produce 2 daughter cells/genetic clones
Cell cycle
Two major phases of the cell cycle
Interphase and metabolic phase
The sum of all chemical reactions, energy growth and reproduction
Metabolic phase
What are the four phases of mitosis?
Prophase, metaphase, anaphase, telophase
Chromatin condenses into visible chromosomes and the nuclear membrane starts to break down; DNA coils into visible chromosomes
Prophase I
Chromosomes line up along the equator of the cell at the metaphase plate
Metaphase I
Sister chromatids remain attached; chromosomes or chromatids are pulled to opposite poles of the cell by spindle fibers
Anaphase I
New nuclear membranes form, chromosomes gather at poles of cell and the cell begin to divide into two daughter cells
Telophase I
What are the four cell cycle phases
G1, s, G2, m
Cell grows and prepares for DNA replication
G1 (Gap 1) Phase
DNA is replicated creating an exact copy of genetic material
S (synthesis) phase
The cell further prepares for cell division by synthesizing proteins and organelles needed for mitosis
G2 (Gap 2) Phase
The cell undergoes mitosis, where the replicated chromosomes are separated and distributed into two new daughter cells
M (mitosis) Phase
What are the three checkpoints in cell cycle
G1, G2/m, m/spindle
Determines if the cell is healthy enough to replicate & divide its DNA and enter S phase. (Primary point for external signal influence)
G1 checkpoint
Insures DNA replication is complete and there is no damage before the cell enters mitosis
G2/M checkpoint
Verifies all chromosomes are properly attached to the spindle fibers before the cell progresses from metaphase to anaphase
M/spindle checkpoint
The occurrence of one or more extra or missing chromosomes in a cell or organism
Aneuploidy
Genetic disorder with three copies of a chromosome instead of two
Trisomy
Cell only has one chromosome from a pair instead of two
Monosomy
What is the purpose of mitosis in a multicellular organism like a human?
To provide new cells for growth, development and repair by creating identical copies of existing cells
What is the guardian of the genome?
Protein P53
What are the causes of mutations?
Errors occurring during replication, where genetic code is copied during cell division; exposure to environmental factors such as mutagens like radiation or chemicals
A reproductive cell of an animal or plant; egg or sperm
Gamete
Two complete sets of chromosomes with one set coming from each parent
Diploid
Contains only one set of chromosomes
Haploid
The end result of meiosis in a human cell is four of these cells
Haploid
Pairing process in early meiosis of hemologous pairs of chromosomes
Synapsis
Cytoplasmic division of a cell at the end of mitosis or meiosis resulting in two daughter cells
Cytokinesis
A complex of proteins at the centromere of a chromosome where the microtubules of the spindle attach during cell division
Kinetochor
DNA prior to chromosome formation at mitosis
Chromatin
Describes a cell, nucleus, or organism containing two sets of chromosomes (2n)
Diploid
Describes a cell, nucleus, or organism containing one set of chromosomes (n)
Haploid
The period of the cell cycle at which the duplicated chromosomes are separated into identical nuclei; includes prophase, pro metaphase, metaphase, anaphase, and telophase
Mitosis
The division of the cytoplasm following mitosis to form two daughter cells
Cytokinesis
The ordered sequence of events that a cell passes through between one cell division and the next
Cell cycle
Promotes and guides the coiling of DNA
Nucleosome
Promotes and guides the coiling of DNA
Nucleosome
True or false: Humans are diploid. With two sets of chromosomes. In each set, 22 are Autosomes and 1 is the sex (X or Y).
True
True or false: There are 46 total chromosomes in somatic cells
True
true or false: Gametes (haploid) Have one set of chromosomes
True
True or false: the genome is the complete set of genes or complete compliment of DNA
True
The visual representation of an individual’s complete set of chromosomes; from the nucleus of a eukaryotic cell
Karyotype
True or false: gene expression controls regulate the cell cycle at different points
True
Loss of cell cycle controls can result in
Cancer
A malignant growth or tumor caused by uncontrolled cell division of abnormal cells
Cancer
The cell cycle is integrated around two concepts (two irreversible points)
Replication of genetic material (dna) and separation of the sister chromatids
Cell cycle can put a hold on specific points called
Checkpoints
A process in which points are checked for accuracy and can be halted if there are errors; allow cell to respond to internal and external signals
Checkpoints
Major tumor suppressor genes; creates the checkpoint protein creation due to mutations or viruses causes tumors and may end up as cancer.
Protein P53
Guardian of the genome
P53
This will accumulate when there is a gene mutation
P53
If DNA cannot get repaired, & P-53 does not get degraded, The accumulation leads to
Altruistic apoptosis
UV radiation, pollution, chemicals, oxidative stress, hypoxia can cause a mutation in what protein?
P-53
True or false: p-53 causes cell death if DNA is not repairable
True
True or false: P-53 puts hold on cell cycle (G1- S0) to allow DNA repair
True
Normal cellular geness that become oncogenes when mutated, oncogenes can lead to cancer
Proto-oncogenes
True or false: some oncogenes encode growth factory receptors. If a receptor is mutated to be “On” The cell no longer depends on binding with a growth factor
True
True or false: some oncogenes encode signal transduction proteins
True
How do protocogenes become ocogenes?
UV radiation, pollution, chemicals, oxidative stress, hypoxia
Cancers can be divided into three groups…
Carcinomas, sarcomas and leukemias/lymphomas
This cancer arises from epithelial cells skin, lining to colon, lung, liver, bladder, breasts
Carcinomas
Bone or muscle cell cancer
Sarcoma
Blood cancers
Leukemia / lymphomas
A cancer of an epithelial cell, the squamous cell,; primary part of the epidermis of the skin; can also occur in the lining of the digestive tract, lungs, and other areas of the body
Squamous cell carcinoma
Malignant tumor of melanocytes; less common than other skin cancers; More dangerous if not found early; causes the majority of deaths related to skin cancer
Melanoma
True or false: approximately 10 cancer cells develop in our body everyday
True
True or false: The body has additional methods to respond to cancerous cells (beyond checkpoint proteins)
True
True or false: natural killer/T cells in our body recognize and destroy cancer cells
True
