Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
68 Cards in this Set
- Front
- Back
|
Cell Division
|
The reproduction of a cell
|
|
|
Cellular reproduction
|
two daughter cells that result are genetically identical to each other and to the original parent cell. Each contains 46 single chromosomes.
|
|
|
Chromosomes
|
The structures that contain most of the cell's DNA. Before parent cell splits into two, it duplicates its chromosomes. then each daughter cell gets one set of those chromosomes during division.
|
|
|
the roles of cell division
|
replaces damage or lost cells, and reproduction and growth.
|
|
|
asexual reproduction
|
offspring produced inherit all of their chromosomes from a single parent.
|
|
|
sexual reproduction
|
requires fertilization of an egg by a sperm.
|
|
|
Gametes
|
a sex cell. A haploid egg or sperm. The union of two gametes produces a zygote. Has half as many chromosomes as the parent cell it comes from.
|
|
|
Haploid
|
Containing a single set of chromosomes. referring to an a cell.
|
|
|
Diploid
|
Containing two sets of chromosomes (pairs of homologous chromosomes) in each cell, one inherited from each parent, referring to a 2n cell.
|
|
|
Homologous chromosomes
|
the two chromosomes that make up a matched pair in a diploid cell. Homologous chromosomes are of the same length , centromere position, and staining pattern and possess genes for the same characteristics at corresponding loci. One homologous chromosome is inherited from the organism's father, and the other from the mother.
|
|
|
Meiosis
|
involves a special type of cell division, which occurs only in reproductive organs (such as testes and ovaries).
|
|
|
Cell nucleus
|
contains nearly all genes of organism, which are located on chromosomes. (with exception of small DNA found in mitochondria and chloroplasts.)
|
|
|
Chromatin
|
fibers that make up DNA from DNA and protein molecules.
|
|
|
Histones
|
small proteins that associate with DNA to pack it into the nucleus of eukaryotes cells only. DNA must be packed before it can be moved to a new cell.
|
|
|
Nucleosome
|
each bead ( which consists of DNA wound around histone molecules. When not divuding, the DNA of active genes takes on this lightly packed beads on string arrangement. once they prepare to divide, chromosomes condense even more. Next level of packing- the beaded string is wrapped into tight helical fiber. Then this fiber coils further into a thick supercoil.
|
|
|
Before begins division
|
it duplicates all of its chromosomes. The result is each chromosome consists of two sister chromatids.
|
|
|
Sister Chromatids
|
One of two identical parts of a duplicated chromosome. while joined, two sister chromatids make up one chromosome. Chromatids are eventually separated during mitosis or Meiosis II.
|
|
|
Duplication and distribution of a single chromosome
|
i- chromosome duplication
ii - sister chromatids i i - chromosome distribution to daughter cells. ( during cell reproduction, the cell duplicates each chromosome and distributes the two copies to the daughter cells. |
|
|
Centromere
|
the two sister chromatids are joined together tightly at a narrow waist.
|
|
|
Cell cycle
|
the ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division into two cells
|
|
|
Cell cycle
|
G1 --- S phase --- G2 ----Mitosis( division of nucleus) ----Cytokinesis( division of cytoplasm)
|
|
|
Interphase
|
a time when a cell performs its normal functions within the organism. During this phase, a cell doubles everything in its cytoplasm. Including: proteins, many of its organelles, and its size. Lasts for typically 90℅ of cell cycle. Is when chromosomes duplicate.
|
|
|
S phase
|
DNA in the nucleus is doubled in interphase.
|
|
|
G2 phase
|
each chromosome in the cell consists of two sister chromatids and the cell during this period is preparing to divide.
|
|
|
Mitotic phase
|
the phase when the cell actually divides. It includes 2 overlapping phases ( mitosis and cytokinesis).
|
|
|
Mitosis
|
the nucleus and its contents ( the duplicated chromosomes) divide and are evenly distributed, forming two daughter nuclei.
|
|
|
Cytokinesis
|
The cytoplasm is divided in two
|
|
|
Mitosis and Cytokinesis
|
Prophase
Metaphase Anaphase Telophase and Cytokinesis |
|
|
Interphase
|
the cytoplasm contains two centrosomes ( with centriole pairs). Within the nucleus, the chromosomes are duplicated but cannot be distinguished yet.
|
|
|
Prophase
|
in nucleus- chromatin fibers coil ( become thick enough to see individually). Each chromosome exists as two identical sisters chromatids joined together.
in cytoplasm- the miotic spindle begins to form as microtubules grow out from the centrosomes, which are moving away from each other. Late in prophase, the nuclear envelope begins to break into pieces. The spindle microtubules attach to the centromeres of the chromosomes and move the chromosomes toward the center of the cell. |
|
|
Metaphase
|
The mitotic spindle is now fully formed. The centromeres of all chromosomes line up between the two poles of the spindle. For each chromosome, the microtubules if the mitotic spindle attached to the two sister chromatids pull toward opposite poles. This tug of war keeps the chromosomes in the middle of the cell.
|
|
|
Anaphase
|
Anaphase begins suddenly when the sister chromatids of each chromosome seperate . Each is now considered a full-fledged (daughter) chromosome. The cell elongates.
|
|
|
Telophase and Cytokinesis
|
Telophase begins when the two groups of chromosomes have reached opposite ends of the cell. Telophase is the reverse of prophase. Nuclear envelopes form, the chromosomes uncoil, and the spindle disappears. Mitosis, the division of one nucleus into two genetically identical daughter nuclei, is now finished. Cytokinesis occurs when the cytoplasm divides.
|
|
|
Cell control system
|
directs the events of the cell cycle that consists of specialized proteins within the cell.
|
|
|
Cleavage furrow
|
an indentation on the equator of the cell pinching the parent cell in two.
|
|
|
Cell plate
|
in plant cells, the vesicles fuse forming a cell plate which grows outward.
|
|
|
Cancer
|
kills 1 out of every 5 people in the U.S. is a disease of the cell cycle. cells divide excessively and invade body tissues.
|
|
|
Metastasis
|
the spreading of cancer cells beyond their original site.
|
|
|
Somatic Cell
|
has 46 chromosomes. a typical body cell (non sexual).
|
|
|
Karyotype
|
a picture of matching pairs. Each chromosome is duplicated
|
|
|
Interphase before Meiosis
|
Pair of Homologous chromosomes in diploid parent cell
Duplicated pair of homologous chromosomes with sister chromatids. |
|
|
Meiosis I
|
Homologous Chromosomes seperate
|
|
|
Meiosis II
|
Sister chromatids separate.
|
|
|
Random fertilization
|
one gamete unites with another randomly.
|
|
|
crossing over
|
the exchange of corresponding segments between nonsister chromatids of homologous chromosomes.
|
|
|
nondisjunction
|
a mishap when members of chromosome pair fail to seperate at Anaphase.
|
|
|
Down syndrome
|
an extra chromosome 21.
|
|
|
Multiple alleles for ABO blood groups
|
Phenotype. GT RBC. antibody
A. IA IA or IA I B AB O |
|
|
Heredity
|
the transmission of traits from one generation to the next.
|
|
|
Genetics
|
the science study of heredity.
|
|
|
character
|
a heredity feature that varies among individuals within a population.
|
|
|
hybrid
|
babies from two different species or parents with different characteristics.
|
|
|
p genrartion
|
The parent individuals from which offspring are derived in studies of inheritance.
|
|
|
F1 generation
|
The offspring of two p generation.
|
|
|
F2 generation
|
the offspring of F1 generation
|
|
|
Law of segregation
|
A general rule of inheritence - states that the two alleles in a pair segregate into different gametes during meiosis.
|
|
|
law of independent assortment
|
states that when gametes form during meiosis, each pair of alleles for a particular character separate independently of each pair.
|
|
|
pedigree
|
A family tree of the occurrence of inherited traits across offspring lines.
|
|
|
wild type traits
|
the trait most commonly found in nature
|
|
|
rule of multiplication
|
states the probability of a compound event is the product of two separate probabilities of independent events.
|
|
|
testcross
|
the mating between an individual of unknown genotype for a particular character and an individual that is homozygous recessive for that same character.
|
|
|
dihybrid cross
|
a mating of individuals differing at two genetic loci.
|
|
|
locus
|
the particular site where a gene is found on a chromosome.
|
|
|
genotype
|
the genetic make-up of an organism.
|
|
|
phenotype
|
the expressed traits of an organism.
|
|
|
monohybrid cross
|
a mating of individuals differing at one genetic locus.
|
|
|
plieotrpy
|
the control of more than one phenotype character by a single gene.
|
|
|
polygenic inheritence
|
the additive effect of two or more genes on a single phenotypic characteristic.
|
