Genetics: Exam 2
Mendel's data for crosses between variants of seven characters are as follows:
-P cross tall stem versus dwarf stem, F 1 generation all tall; F 2 generation 787 tall and 277 dwarf, which is a 2.84 to 1 ratio; -P cross purple versus white flowers, F 1 generation all purple; F 2 generation 705 purple and 224 white, which is a 3.15 to 1 ratio; P cross axial versus terminal flowers, F 1 generation all axial, F 2 generation 651 axial and 207 terminal, which is a 3.14 to 1 ratio; -P cross yellow versus green seeds, F 1 generation all yellow, F 2 generation 6,022 yellow and 2,001 green, which is 3.01 to 1 ratio; -P cross round versus wrinkled seeds, F 1 generation all round, F 2 generation 5,474 round and 1,850 wrinkled, which is a 2.96 to 1 ratio; -P cross green versus yellow pods, F 1 generation all green; F 2 generation 428 green and 152 yellow, which is a 2.82 to 1 ratio; -P cross smooth versus constricted pods, F 1 generation all smooth, F 2 generation 882 smooth and 299 constricted, which is a 2.91 to 1 ratio. -For all crosses, the F 1 generation showed the dominant trait, F 2 generation totals were 14,949 dominant and 5,010 recessive, which is a 2.98 to 1 ratio.
Know the 4 conclusions that Mendel made from his data as described :
1) Mendel's data argued strongly against a blending mechanism of heredity. 2) His data suggested that the genetic determinants of traits are passed along as discrete "unit factors" from generation to generation. 3) Mendel stated that........unit factors occur in pairs. When one unit factor for a particular character is present simultaneously with a second distinct unit factor within the same individual—one of the factors will be dominant over the other variant of the factor which will said to be recessive. 4) Mendel also stated that... genes must segregate from each other during the process that gives rise to gametes (Now called Meiosis I Anaphase I).
1. The cells of MITOSIS OR MEIOSIS?? are terminal for animalia they will not undergo any more divisions 2. In plants the haploid spores can divide in a cell cycle that uses MITOSIS OR MEIOSIS?? and generates haploid daughter cells of a multicellular haploid gametophyte generation. Some Fungi and some Protists also do this. 3. The multi celled gametophyte will produce __________ ________ that will generate sperm and egg. 4. The fusion of these gametes will produce a diploid zygote that will use MITOSIS OR MEIOSIS?? to generate a multicellular diploid stage called a ________. 5. Fungi form zygotes but do not form _______. 6. They immediately take their zygotes into MITOSIS OR MEIOSIS?? to produce spores then these divide via mitosis to produce a hyphal body which is like a gameotophyte and spend most their lives as haploid multi-celled structures.
1. MEIOSIS 2.MITOSIS 3. HAPLOID GAMETANGIA 4.MITOSIS, SPOROPHYTE 5.SPOROPHYTES 6.MEIOSIS
1. MITOSIS OR MEIOSIS?? produced two diploid daughter cells . 2. MITOSIS OR MEIOSIS?? produced four haploid daughter cells . 3. MITOSIS OR MEIOSIS?? has halved the number of chromosomes per cell. . 4. The daughter cells produced by MITOSIS OR MEIOSIS?? are genetically identical. . 5. The haploid cells produced by MITOSIS OR MEIOSIS?? are not genetically identical to each other because they contain only one homologous chromosome from each pair and have crossed over products.
1. Mitosis 2. Meiosis 3. Meiosis 4. Mitosis 5.Meiosis
Know........The purpose of "packaging up" the DNA this way is two fold
1. to fit all this DNA into the nucleus. This is accomplished at the nucleosomal and solenoid level 2. so it's copies can be moved into separate daughter cells with ease. This is accomplished by compacting further to the 300 and 700nm level
The amount of DNA required to wrap around the histone octamer is _____ or ____ bp. This followed by a ____ bp unwrapped segment.
146 or 147 bp, 60
Know that.......Bacteria can divide every ____ to ____ minutes.
20 to 30
Law of Segregation. Within experimental variation, he always observed approximately a ___:___ ratio between the dominant and the recessive trait.
3:1
A fully compacted chromosome is ______nm in diameter and very visible under the light microscope
700nm
Know the following about S phase: In the S phase, chromosomes are replicated. After replication, the two copies are called chromatids. They are joined to each other at a region of DNA called the centromere to form a unit known as....
A pair of sister chromatids, or a dyad.
WHAT PHASE IS THIS?? 1) Tetrads separate. 2) Bivalents separate, 3) paired homologs separate, 4) paired homologous chromosomes separate, 5) two dyads within a tetrad separate from each other and migrate to opposite poles.
ANAPHASE I
Is this PLANT OR ANIMAL Cytokinesis . -In most cases, mitosis is quickly followed by cytokinesis, in which the two daughrer nuclei are segregated into separate daughter cells. -Likewise, cytokinesis also segregates cell organelles, such as mitochondria and chloroplasts, into daughter cells. In animal cells, cytokinesis begins shortly after anaphase or at the onset of telophase. -A contractile ring, composed of myosin motor proteins and actin filaments, assembles at the cytoplasmic surface of the plasma membrane. Myosin hydrolyzes ATP, which shortens the ring, thereby constricting the plasma membrane to form a cleavage furrow that ingresses, or moves inward. Ingression continues until the cell is divided into two cells. .
ANIMAL
Other preRC proteins also bind the ________ joining with the ORC proteins forming a large complex and leading to separation of the AT-rich regions.
ARS1
Eukaryotic origins include ________ in ______ and also have several repeats that are AT rich
ARS1 in yeast
ASTER/POLAR/KINETOCHORE???? microtubules emanate away from the region between the poles. They help to position the spindle within the cell and anchor the ends of the spindle. Astral microtubules develop in the actin skeleton and interact with the cell cortex to aid in spindle orientation. They are organized into radial arrays around the centrosomes. Astral microtubules are not required for the progression of mitosis, but they are required to ensure the fidelity of the process. They are absolutely required for correct positioning and orientation of the mitotic spindle apparatus,
ASTER
Each _____ appears on its' own separate homologous chromosome.
Allele
The term _____ (from the Latin alius meaning other) refers to an alternative version of a particular gene.
Allele
homologs may carry different versions of a given gene, which are called.....
Allele
At fertilization, two gametes combine randomly, potentially producing different _______ combinations. For example --A sperm with the dominant allele combines with and fertilizes and egg carrying a recessive allele to produce a hybrid.
Allelic
The slight differences in DNA sequences provide the......
Allelic differences in genes.
Microtubules are produced from the rapid polymerization of _______ and _______ tubulin proteins.
Alpha and Beta
Certain unicellular eukaryotes, such as the _______ and _______ ________ (Saccharomyces cerevisiae), can reproduce asexually.
Amoeba and baker's yeast
During _________, sister centrosomes are forced apart as the spindle elongates, allowing each daughter cell to receive one centrosome to organize its microtubules in the next cell generation.
Anaphase
To do this, the sensing mechanism ensures that the _______-promoting complex is no longer inhibited, which is now free to degrade cyclin B, , and to break down securing--whose function is to inhibit separase enzymes--, which in turn cuts the cohesins, the protein composite responsible for cohesion of sister chromatids.
Anaphase
What phase is this?? -the connection that is responsible for holding the pairs of chromatids together is broken. The enzyme known as _______ dissolves the cohesin molecules that binds sister chroamtids together. -the spindle fibers (kinetochore MTs) pull on each pair of sister chromatids and pull them in opposite directions pulling them apart at the centromere splitting the centromere and separating or disjoining the two sister chromatids away from each other. -each chromatid or monad, is now an individual chromosome, and is -linked to only one of the two poles. Note at this point ....there are ZERO chromatids in the cell. -the daughter chromosomes move/migrate toward the pole to which they are attached. This involves a shortening of the kinetochore microtubules. In addition, the two poles themselves move farther apart due to the elongation of the polar microtubules, which slide in opposite directions due to the actions of motor proteins
Anaphase SEPARASE
After separation of the tetrads the daughter chromosomes which have two chromatids each migrate to opposite poles. Here in WHAT PHASE?? chromatids are present as compared to mitosis in which no chromatids are in the cell after the chromatids pull apart or disjoin.
Anaphase I
_______ __ segregates the dominant allele on the maternal homolog from the recessive allele on the paternal homolog. Sending them to opposite poles. Therefore, only one copy of each allele/gene form is found in the final gamete. . ½ of the sperm will have the chromosome with the dominant _________ . the other ½ of the sperm will have the chromosome with the ______ _______
Anaphase I Allele Recessive allele
WHAT PHASE DO THEY DESCRIBE?? -The microtubules on both sides of the chromosome pair pull on the attached chromatids. -This pull separates the related but now different sister chromatids at the centromere and begins the movement of the chromatids to opposite ends of the cell. -The chromatids can now be referred to as daughter chromosomes. At the end of anaphase II, each pole of the cell has a haploids set of daughter chromosomes that are varied in genetic content
Anaphase II
Anti-cancer drugs are anti-mitosis drugs -______ _______. Examples are ______ and ______.
Anti mitogenics Taxol and Vinblastine
Nevertheless, it should be emphasized that the sequences of homologs ARE IDENTICAL OR NOT IDENTICAL??
Are not identical.
Centromeres
Are regions that play a role in the proper segregation of chromosomes during mitosis and meiosis.
Binary fission is an _______ form of reproduction because it does not involve genetic contributions from two different gametes.
Asexual
Echinodermata star fish can regenerate new star fish from severed arms via ___________ reproduction.
Asexual
Humans use ___________ reproduction to replace skin cells, hair cells and blood cells on a daily basis.
Asexual
Single celled Zygotes grow and develop into multicelled organisms via _____________ reproduction.
Asexual
__________ eukaryotic cell division is designed to produce two daughter cells that have the same number and types of chromosomes as the original mother cell. This requires a replication and division process that is more complicated than simple binary fission
Asexual
It is reproduction which never involves reductional changes in chromosome number.
Asexual reproduction
__________ ________ is agamogenesis which is reproduction without the fusion of gametes.
Asexual reproduction
_____________ ___________ is the primary form of reproduction for single-celled organisms such as the archaebacteria, eubacteria, and protists.
Asexual reproduction
a._________ ________ is a mode of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only.
Asexual reproduction
Many plants and fungi reproduce ____________ as well. i.e. Adventitious leaves growing off a parent plant can dislodge and become whole plants that are genetically identical to the parent.
Asexually
Some protists such as Cnidarian jellies reproduce ________via budding. i.e. hydrozoan medussae.
Asexually
MTOC's in centrosome or nuclear envelopes will generate a Mitotic Spindle Apparatus composed of three types of fibers:
Aster Polar Kinetechore
Meiosis I is _________ during anaphase I and produces a LARGE haploid secondary oocyte and a much smaller cell, known as a ____ ________ _______. Most of the cytoplasm is retained by the ______ ______ and very little by the polar body. Allowing the ________ _______ to become a larger cell stores it with more nutrients.
Asymmetrical 1st polar body Secondary oocyte Secondary oocyte
binding of orgins leads to ______ of the _____ around the origin which allows _____________to enter and separate the DNA
Bending of the DNA around the origin which allows helicases
When a tumor does not metastasize it is called ______when it spreads it is called a _______ tumor.
Benign, malignant
Which gap phases are critical periods in the cell cycle that involve many molecular changes?
Both gap 1 and 2
Over the course of 2 years, Mendel tested his pea strains to determine if their characteristics _____ _____ (pure breeding)
Bred true
If DNA is damaged Wee1, a protein phosphorylates _____1 (part of MPF) at Tyrosine 15 which inactivates it and halts cell cycle progression since cdc25 is inactive and can not remove the phosphate off of _____.
CDK1,CDK
If checkpoint regulation is working correctly such mutations and DNA damage will be corrected and repaired and not passed onto daughter cells and hence _______ will be prevented.
Cancer
________ is abnormal mitosis. ______represents a loss of control over the cell cycle and the cell cycle check points.
Cancer
The fusion of vesicles gives rise to the ______ ______, which is a ________-bound compartment. The ______ _____ begins in the middle of the cell and expands until it attaches to the mother cell wall .
Cell Plate, Membrane, Cell Plate
Eukaryotic species have one or more sets of chromosomes in the WHAT?
Cell nucleus
By comparison, most eukaryotic cells are only 10-100 μm in diameter, and the _____ ______ is only about 2-4 μm in diameter.
Cell nucleus.
A few plants do have centrosomes but almost always without.......
Centrioles
______________ or ___________ are exactly 180 degrees on opposite sides of the cell.
Centrioles or centrosomes
These three terms are often confused within the field of Genetics
Centromeres, Centrioles, Centrosomes
Know that.......In animals a pair of centrioles at right angles to each other is found within each _______. Each centriole has nine sets of triplet microtubules.
Centrosome
___________ are absent from up to half of known eukaryotic species including most fungi, protists and vascular plants and from the spindles and interphase arrays of many algae.
Centrosomes
In many plants, no _________ or _______ exists at all and instead the nuclear envelope functions as an ________ for spindle formation.
Centrosomes, centrioles, MTOC.
Cell cycle ___________ are control mechanisms that ensure the fidelity of cell division in eukaryotic cells. These _____________ verify whether the processes at each phase of the cell cycle have been accurately completed before progression into the next phase. Multiple _____________ have been identified, though some of them are less understood than others.
Checkpoints
_____________is only used when the two sisters are physically connected...once they break contact with each other they become __________.
Chromatid, chromosomes
DNA and its proteins in this loose state are by convention called ............ (in almost all textbooks). .
Chromatin
Eukaryotes accomplish this compaction by the binding of their DNA to many different cellular proteins. The DNA-protein complexes found within eukaryotic chromosomes are termed........
Chromatin
Technically chromatids and chromosomes are composed of ___________ which is by strictest definition DNA plus proteins
Chromatin
When someone says DNA goes from chromatin state to chromosome state...they are referring to this definition of _____________...DNA goes from a loose, unfolded, decondensed, unpackaged, uncoiled "7nm chromatin" state to a highly organized, folded, condensed, packaged, coiled "700 nm chromosome" state.
Chromatin
In what phase is chromatin condensed?
Chromatin Condensation during Prophase
This compaction is usually taking place to a greater extent during prophase of M phase of the cell cycle when the chromatin becomes compacted into the thicker condensed form of chromatin known formally as........
Chromosomes
Define the term chromosome and understand their structures
Chromosomes are structures found within living cells and contain the genetic material. Some are circular in bacteria and some are linear in eukaryotes. This term—means colored body.
In bacteria, which have a single CIRCULAR OR MULTICIRCULAR chromosome, the division process is relatively simple.
Circular
Meiosis occurs in sexually reproducing organisms to ______ ____ ______(gametes) (germ cells) that fuse and contain half the number of chromosomes of the original cell that underwent meiosis.
Create sex cells
To begin his heredity studies....Mendel wanted to make crosses between different pea plants. . This process is known as ________ _______.
Cross fertilization
________ _________ requires that the pollen from one plant be placed on the stigma of another plant.
Cross fertilization
. In this way, he was able to ________ _______ his pea plants, thereby obtaining any type of hybrid he wanted.
Cross-fertilize
________ ______ involves a physical exchange of chromosome pieces. Depending on the size of the chromosome and the species, an average eukaryotic chromosome incurs a couple to a couple dozen crossovers. During spermatogenesis in humans, for example, an average chromosome undergoes slightly more than two crossovers, whereas chromosomes in certain plant species may undergo 20 or more crossovers. Recent research has shown that crossing over is usually critical for the proper segregation of chromosomes. In fact, abnormalities in chromosome segregation may be related to a defect in _______ _______.
Crossing over
WHAT DIVISION IS THIS?? This is the division or "pinching" of the parent cell's cytoplasm to form four separate daughter cells or gametes in animal cells or the formation 4 spores via a cell plate synthesis event in Plant cells
Cytokinesis
The final step of Meiosis II is ________ ____.
Cytokinesis II
The final step of Meiosis II is..... This is the division or "pinching" of the parent cell's cytoplasm to form four separate daughter cells or gametes in animal cells or the formation 4 spores via.
Cytokinesis II
Two MCM helicases one at each fork begin _____ _______ ______ _______ within the oriC origin region and continue to separate the DNA strands beyond the origin moving in opposite directions. This process creates a _______ ________—one which be created continuously toward an opening fork. Hence in a replication bubble there are two leading strands one being made toward the left fork and one being made toward the right fork. This also creates a ______ _______-a strand of newly created double strand DNA being synthesized in a direction opposite of the opening fork—away from that fork--. Hence in a replication bubble there are two LEADING STRANDS OR LAGGING STRANDS one being made away from the left fork and one being made away from the right fork.
DNA double strand separation, Leading strand, Lagging strand, Lagging strand.
WHAT DO THEY DESCRIBE?? A. the _______ continue to terminalize towards the telomeres. B. the __________ complex completely disappears. C. the _______ ______ disappears. D. the _______ ______ to tetrad based kinetichores on the centromeres E. tetrads are moved to the __________ or __________ _______.
Diakinesis A. Chiasma B. Synaptonemal C. Nuclear envelope D. Spindle attach E. Equator or metaphase plate
Mutant flies lacking centrioles develop normally, although the adult flies' cells lack flagella and cilia and as a result, they DIE OR LIVE??shortly after birth
Die
Mendel reasoned that pea plants (eukaryotes) must have two paired copies of (unit factors) aka genes. These paired copies may be the same or they may DIFFER OR BE THE SAME?? (allelic).
Differ
When maternal and paternal gametes fuse during fertilization _________ zygotes are formed which develop into ______ offspring.
Diploid
Most eukaryotic species are ________ or have a ______ phase to their life cycle, which means that each type of chromosome is a member of a pair.
Diploid, diploid
WHAT DO THEY DESCRIBE?? A. The recombined non sister chromatids of each homolog pair separate slightly revealing "X" like crossed areas or chiasma which represent the specific points were genetic information has been exchanged. B. Terminalization of chiasma occurs towards the end of _______ into the onset of diakinesis.
Diplonema
During the G1 phase, a cell prepares to _______
Divide
Origins bind proteins such as _________ in bacteria or the ______proteins in yeast.
DnaA and ORC
Centrioles are not required to generate spindle fibers and in plants the PCM does not surround centrioles, because 99% of the few plants that have centrosomes HAVE OR DONT HAVE???centrioles within them again pointing out that centrioles are not needed for _________ _________ _________.
Dont have, miotic spindle formation.
Several properties of Pea Plants were particularly advantageous for studying their inheritance properties. - - - - - - -
Easy to grow Exhibits many visually observable traits Exhibits very little genetic variation It bears flowers and fruit in the same year a seed is planted It produces a large number of seeds It is monoecious having both male and female parts and hence can be easily self-fertilized
PROKARYOTIC OR EUKARYOTIC???? Cells Progress Through a Cell Cycle to Produce Genetically Identical Daughter Cells.
Eukaryotic
The DNA within a typical ________ ________ is a single, linear double-stranded molecule that may be hundreds of millions of base pairs in length.
Eukaryotic chromosome
__________ __________-_____ _______ _______ (RPA proteins) bind to the single strands of parental DNA created by helicase and prevent the single strands from re-forming a double helix. In this way, the bases within the parental strands are kept in an exposed condition that enables them to hydrogen bond with individual nucleotides.
Eukaryotic single-strand binding proteins
How many sets of chromosomes do Eukaryotic species have?
Eukaryotic species have one or more sets of chromosomes in the cell nucleus.
In asexual reproduction the offspring will be DIFFERENT OR EXACT?? genetic copies of the parent (clones).
Exact
Polymerase Switch Occurs..... DNA Polymerase a (alpha) after polymerizing 20-30 nucleotides dissociates from the replication fork and is _________ for DNA polymerase e(epsilon) on the leading strand or DNA polymerase d (delta) on the lagging strand
Exchanged
Mendel's P cross of true breeders produced the offspring that constitute the __1 _________The F stands for first ______ _______.
F1 generation Filial generaton
To produce an F2 requires crossing F1 progeny with other F1 progeny, F1 siblings crossed with F1 siblings...or in monecious bisexual organisms crossing them with themselves, since both sperm-pollen and egg are made within the same flower. For example.......
F1 x F1--> F2 . Sibling x Sibling-->F2 . Tall hybrid x Tall hybrid -->F2 . In this instance the F2 generation showed 75% (3/4ths) of the F2 offspring were Tall and 25% (1/4th) were short
Flowering plants and cone bearing plants are not heterosporous producing both female megaspores and male generated microspores. TRUE OR FALSE???
FALSE. They are heterosporous producing both female megaspores and male generated microspores.
In flowering plants (angiosperms), and cone bearing gymnosperms however, spores develop into gametophytes that contain only one cell. In this case, the organism that we think of as a "plant" is the sporophyte, whereas the gametophyte is very inconspicuous. TRUE OR FALSE??
FALSE. gametophytes that contain only a FEW cells. In this case, the organism that we think of as a "plant" is the sporophyte, whereas the gametophyte is very inconspicuous.
-The structure of a sperm cell includes a long ________ and a ________. -The head of the sperm contains little more than a haploid nucleus and an organelle at its tip, known as an ________. The _______ contains digestive enzymes that are released when a sperm meets an egg cell. These enzymes enable the sperm to penetrate the outer protective layers of the egg (______ _____) and gain entry into the egg cell's cytosol.
Flagellum and a head Acrosome Acrosome Zona pellucida
By the end of prometaphase, the mitotic spindle is completely _______. With all chromosomes aligned on a ______ ______ of a spherical globe like cell structure.
Formed Equatorial plate
Spermatogenesis Produces how many haploid sperm cells?
Four haploid sperm cells
Recent evidence has shown that bacterial species produce a protein called _________, which is important in cell division. This protein assembles into a ring at the future site of the septum. _____ is thought to be the first protein to move to this division site, and it recruits other proteins that produce a new cell wall between the daughter cells.
FtsZ
In addition, cells may remain permanently, or for long periods of time, in a phase of the cell cycle called.....
G0
At the very end of G1 right before S phase proteins such as MCM helicases and ligases and primases and RPA proteins and DNA polymerase alpha, delta and epsilon may begin to be produced so they can be used in the forthcoming S phase to replicate DNA.
G1
Centrioles were previously thought to be required for the formation of a mitotic spindle in animal cells. However, more recent experiments have demonstrated that cells whose centrioles have been removed via laser ablation can still progress through the_______ stage of interphase.
G1
Depending on the cell type and the conditions that it encounters, a cell in the G1 phase will begin to manufacture new molecules.
G1
The cell will produce new mRNA molecules via transcription, produce new proteins via translation of the new mRNA molecules, produce new phospholipids to expand the smooth and rough ER or Golgi or plasma membrane, create new cholesterol molecules via the smooth ER to be placed in the new and growing plasma membrane, new carbohydrates will be made to be placed on glycoproteins and glycolipids.
G1
The overall purpose for such active metabolic activity during G1 is to double or duplicate all cell organelles and structures so that each daughter cell will receive all the organelles they need to exist as independent cells.
G1
If environmental conditions make cell division impossible a cell may stop cell cycle progression at this point. WHAT IS THIS POINT??
G1 (RESTRICTION)
The ______ restriction point is controlled mainly by the action of proteins and enzymes called ______, and _______ dependent kinases and also by inhibitors of _____/____ complexes
G1, Cyclins, cyclin, Cyclin/Cdk.
The first checkpoint in the cell cycle is located at the end of the cell cycle's ______ phase, just before entry into S phase, making the key decision of whether the cell should divide, delay division, or enter a resting stage. Many cells stop at this stage and enter a resting state called ______.
G1, G0
One ______ checkpoint protein regulator is called cdc25. cdc25 removes inhibitory phosphates present within a complex called MPF (cyclin B/CDK1) thus activating the kinase. This allows MPF to add phosphates to substrates needed to proceed into M phase.
G2
The second checkpoint is located at the end of ______phase, triggering the start of the M phase (mitotic phase). In order for this checkpoint to be passed, the cell has to check a number of factors, such as DNA damage via radiation, to ensure the cell is ready for mitosis. If this checkpoint is passed, the cell initiates the many molecular processes that signal the beginning of mitosis. The CDKs associated with this checkpoint are activated by phosphorylation of the CDK by the action of a "Maturation promoting factor" (Mitosis Promoting Factor, MPF) (cyclin B/CDK1 complex).
G2
During sexual reproduction, two gametes fuse with each other in the process of fertilization to begin the life of a new organism. Gametes are highly specialized cells that are produced by a process called _____________.
Gametogenesis
Plant species alternate between haploid and diploid generations. The haploid generation is called the ________, whereas the diploid generation is called the _______.
Gametophyte Sporophyte
________ = the letter representation of an organisms genetic makeup
Genotype
This "blending" idea would be prevalent until ________ ________ proved that genetic factors were particulate in some instances and did not have always have to blend.
Gregor Mendel
Among the 'higher' seed-producing plants, only two orders of ____________, the ______ and ________, retain centrosomes.
Gymnosperm, the cyads and ginkgoes.
MCM a protein complex--which is similar to bacterial DnaB—binds to the other proteins complexed at the ARS1 origin. MCM is a _______. After it binds this completes "DNA replication Licensing" meaning the polymerases can now start DNA synthesis.
Helicase
Centromeres are composed of highly condensed ___________and function as a site for the formation of _________.
Heterochromatin, Kinetechores.
A __________individual carries 2 different alleles of a gene. (The prefix hetero- means....... different.)
Heterozygous
In contrast, the F1 generation progeny are all _______ _______, with the genotype .........Tt .........
Heterozygous dominant
..In a P generation cross between tall TT plants and dwarf tt plants, tall plants can only produce T gametes, and dwarf plants can only produce t gametes, . ......such that when these combine to produce the F 1 generation, all F1 generation individuals are ________, Tt and are tall.
Hetrozygous
In a cell of a diploid organism are diploid sets of chromosomes, two corresponding chromosomes of similar length, centromere position and gene types are called __________; the pair is considered a _________ pair a bivalent .
Homolog, Homologous.
Know that.......When a species is diploid, the members of a pair of chromosomes are called ____________; each type of chromosome is found in a _________ pair. .
Homologs, homologus
.....In the P cross, the tall plant (P1) is __________ dominant for the tall allele T = TT, and the dwarf pea plant (p2) is homozygous recessive for the dwarf allele t = tt. P1 =TT P2= tt P1 (Parent 1).....x.....P2 (Parent 2) = TT.....x.....tt. This is the P cross
Homozygous
Sixteen years later, in 1900, the work of Mendel was independently rediscovered by three biologists with an interest in plant genetics: _________,______,____ of Austria.
Hugo de Vries of Holland, Carl Correns of Germany, and Erich von Tschermak
Know that.......Unlike eukaryotes, which have their chromosomes in a separate nucleus, the circular chromosomes of bacteria are INDIRECT/ IN DIRECT contact with the cytoplasm.
In direct
Once this _______ protein is degraded via ubiquitination and subsequent proteolysis, separase then causes sister chromatid separation.
Inhibitory
THIS IS STILL IN CYTOKINESIS! The daughter cells progress into _________ which is not interphase (no G1 or S or G2 occurs).
Interkinesis
The cell cycle has two major subdivisions:
Interphase M phase
G1 or presynthesis Gap 1 (G for gap) , S phase, or synthesis phase (replication of the genetic material), G2 for post-synthesis Gap 2
Interphase has three further subdivisions:
During WHAT PHASE IS in G1 of the cell cycle DNA in the nucleus of eukarya is unwound and detached from its scaffold proteins and matrix proteins and compacting histone H1 proteins. It is in a very ___________, unfolded, _________, unpackaged, uncoiled state and at the nucleosomal 7nm or solenoid 30 nm level of compaction.
Interphase, loose, decondensed
Prior to mitosis, the cells are in ______, during which the chromosomes are decondensed—less tightly compacted—and found in the _________.
Interphase, nucleus
The first systematic studies of genetic crosses were carried out by _________ ________ from 1761 to 1766. In crosses between different strains of _________ _______, he found that the offspring were usually _________ in appearance between the two parents.
Joseph Kölreuter 1761 to 1766 Tobacco plants Intermediate
When do kinetechores assemble?
Just before and during mitosis and meiosis.
Mitosis is also called karyokinesis
Karyokinesis
Kinetochore microtubules are microtubules that emanate from MTOC's and make connections to the kinetochore plates on each side of the centromere that connects sister chromatids together.
Kinetochore
What do all of these describe?? -Prior to cell division, bacterial cells copy, or replicate, their chromosomal DNA. This produces two identical copies of the genetic material. - Following DNA replication, a bacterial cell divides into two daughter cells by a process known as binary fission. During this event, the two daughter cells become separated from each other by the formation of a septum. - Each cell receives a copy of the chromosomal genetic material. Except when rare mutations occur, the daughter cells are usually genetically identical because they contain exact copies of the genetic material from the mother cell.
Know all the following describing bacterial cell division...
_________ concluded that both parents make equal genetic contributions to their offspring ...blending their contributions. According to this idea, the factors that dictate hereditary traits can blend together from generation to generation
Kölreuter
WHAT DO THEY DESCRIBE??? A. characterized by partial condensation of chromatin leading to the creation of ____________, "beads on a string" like structures that represent points of differential condensation the more condensed regions the "________" stain with color, thus the name chromomeres or color bodies. B. homologous chromosomes carry out _______ ______. Maternal homlogs search their matching patenal homolog to pair with them.
Leptonema Chromomeres Beads Homology search
During prophase I, there are five sub-stages:
Leptonema, Zygonema, Pachynema Diplonema and Diakinesis
When a cell is preparing to divide, the chromosomes become more tightly coiled, which shortens them and increases their diameter. The consequence of this shortening is that distinctive shapes and numbers of chromosomes become visible with a ________ _______.
Light microscope
The first step to accomplish chromatin compaction is to take............ This process forms ____________, the Repeating Structural Unit of Chromatin.
Linear DNA and wrap it Around an octamer of histone proteins. Nucleosomes.
The physical location of a gene on either homologous chromosome is called its
Locus (plural: loci)
In animal cells, the mitotic spindle is formed from two _________ located within centrosomes. Centrosomes arelocated at a ________ _________ at metaphase.
MTOC's. Spindle poles
Once this attachment has taken place, the cell plate undergoes a process of ________ and eventually separates the mother cell into two daughter
Maturation
In ________ these homologs pair up closely in Pachynema of Meiosis I of Prophase I. The maternal and paternal ______ sit side by side in the paired homolog structure.
Meiosis Alleles
Certain cells in the sporophyte undergo _______ and produce haploid cells called _______, which divide by mitosis to produce a male or female or in some cases bisexual __________.
Meiosis Spores Gametophyte
Cells that reproduce through meiosis undergo two cell divisions, known aS...........
Meiosis I and meiosis II
Interphase takes place prior to ________ ___, _________ ____ and is much like _______ prior to mitosis: G1, S, G2...the cell grows, replicates its chromosomes, and produces and assembles the cellular structures needed for cell division.
Meiosis I prophase I, interphase
_______ ____ is the _________ division where chromosome number is reduced in half
Meiosis I, reduction
________ ____is the _______division similar to mitosis. Here the parent cells of ________ ___ have the same (equal) chromosome number as their daughter cell.
Meiosis II, and Equatorial, Meiosis II
What do they have in common?? Occurs in the Testes and Ovaries of Animals Occurs in the Anthers and Ovules of flowering plants (it produces enclosed megaspores and microspores) spores germinate into gametophytes within sporophyte tissue. Gametophytes produce sperm and egg. Occurs in the capsules of bryophytes (mosses, liverworts) whose sporangia release meiotic produced walled spores into the air; spores form gametophytes with antheridia and archegonia which make sperm and egg. Occurs in the sori and strobili of pterophytes and lycophytes (ferns, horse tails, club moss) whose sporangia produce walled spores via meiosis. These spore produce gametophytes to make sperm and egg Meiosis occurs in the pollen scales of pollen cones and ovules of ovulate cones of gymnosperms, which produce microspores and megaspores. These spores stay within sporophyte tissue and produce gametophytes to make sperm and egg. Protist- Brown algae have sporangia on the edges of their underwater blades and sporocytes in these sporangia undergo meiosis and yield biflagellated swimming unwalled zoospores which divide and form male and female gametophytes in water that will use mitosis to generate swimming sperm and egg.
Meiosis Locations
What phase is this?? Eventually, the pairs of sister chromatids align themselves along a plane called the metaphase plate. When this alignment is complete, the cell is in metaphase of mitosis. At this point, each pair of chromatids (each dyad) is attached to both poles by kinetochore microtubules. The pairs of sister chromatids have become organized onto a a single transecting plate along equator. When this organizational process is finished, the chromatids can be equally distributed into two daughter cells.
Metaphase
In an organism that produces many gametes, meiosis can produce many different arrangements of homologs .....the random arrangement of homologs is consistent with Mendel's law of independent assortment. WHAT PHASE IS THIS IN??
Metaphase I
WHAT PHASE DO THEY DESCRIBE?? -A haploid set of chromosomes line up in the center of the cell along an equatorial plane called the metaphase plate. -Each sister chromatid is really no longer a true sister due to crossing over in pachynema prophase I meiosis I. -Microtubules of the meiotic spindle are attached at the centromere kinetochores; to these related but now different sister chromatids. This will allow variable sister chromatids of each chromosome to be pulled to opposite ends of the cell by the meiotic spindle apparatus during the next phase, anaphase II. -Centrioles or centrosomes are exactly 180 degrees on opposite sides of the cell.
Metaphase II
Because most eukaryotic species have several chromosomes per set, the sister chromatids can be randomly aligned along the ___________ ___________ in many possible ways.
Metaphase plant
The spindle apparatus is formed from __________-organizing centers (MTOCs), which are structures found in eukaryotic cells from which microtubules grow. Some MTOC's are found withinin centrosomes others are found in the nuclear membrane.
Microtubule
When the nuclear envelope disperses, the ____________ extend from the centrosome into the former nucleoplasm where the chromosomes have already condensed. Some of these _______ attach to the chromosome kinetechores on the centromere, while others interact with _______ produced by the sister centrosome, (polar microtubules) forming a mitotic spindle that ___________ and__________ the chromosomes.
Microtubules, microtubules, microtubules, organizes and segregates.
DNA is frequently damaged prior to MEOSIS/MITOSIS??, and, to prevent transmission of this damage to daughter cells, the cell cycle is arrested via inactivation of the cdc25 phosphatase which in turn prevents removal of phosphates from MPF which inactivates the kinase.
Mitosis
Hence chromosomes in the practical definition are DNA and protein molecules represented in the highly organized, folded, condensed, packaged, coiled state..... the very visible form that we are use to seeing in a microscope during ________, that we do not see at all during interphase (G1, S, G2) ....where the DNA is too loosely compacted to allow visual observation of any definite structures.
Mitosis
The mitotic spindle allows cells to organize and separate chromosomes so each daughter cell receives the same complement of chromosomes. This sorting process, is known as.....
Mitosis
. The ________ _____ checkpoint occurs at the point in metaphase where all the chromosomes should/have aligned at the mitotic plate and be under bipolar tension. The tension created by this bipolar attachment is what is sensed, which initiates the anaphase entry.
Mitotic spindle
A structure that is observed at the end of M phase and during G1, which is a______ and contains the equivalent of TWO OR ONE??chromatid(s).
Monad, One
A single chromatid within a dyad is called a..... In what phase?
Monad. S Phase
An unreplicated chromosome can also be called a..... In what phase?
Monad. S Phase
If you cross the male hybrid with the female hybrids (Tt x Tt)--- this in some textbooks is also called a __________ ________-the crossing of two single factor hybrids against each other.
Monohybrid cross
.....A cross between two parents with different variants for ONE given character will produce single-character hybrids, also known as _______. Green seeds, Constricted Pods, Curly Hair, Tall, Short, Blue eyes...all are physical features that can be observed.
Monohybrids
A ___________ cross in some textbooks is defined as a cross where a single characteristic is being examined (MONO =single or one) by crossing two parents that have contrasting forms of that characteristic (i.e.Tall/Short) and results in producing a hybrid of those contrasting forms—a __________.
Monohybrids
Species such as plants, animals, most fungi, and some protists are derived from a single _______ ______ that must undergo repeated ___________ __________.
Mother cell, Cellular divisions
By convention, the original cell is usually called the _________ _______, and the new cells are the two _______ _______.
Mother cell, Daughter cell
A second important reason for cell division is _______________.
Multicellularity
__________ and DNA damage passed onto daughter cells may affect genes associated with stimulating cell division or stopping cell division and as a result lead to abnormal out of control cell division
Mutations
There IS OR IS NOT ??? prometaphase I stage.
NOT
Most centrioles are made up of ____ sets of microtubule triplets, arranged in a cylinder. Deviations from this structure include crabs and ___________ _________ ________, with _______doublets, and C. elegans sperm cells and early embryos, with _______ singlets.
Nine. Crabs, and Drosophila melanogaster embryos. Nine Nine
All plants generated by the P cross--the F1 generation--- showed the trait of one parent but not the other. Example: Mendel Crossed Tall Plants with Short Plants - He then collected the seeds aka (peas) which are the embryonic children of the Tall and Short parents. He then planted the peas, and the seeds grew.... leading to the adult fully grown pea plants -the offspring-- of the F1 generation.) He then examined the F1 adult fully grown pea plants and found they all were Tall ...none were TALL OR SHORT???
None were short
A cell in the G0 phase is temporarily PROGRESSING OR NOT PROGRESSING??? through the cell cycle .
Not progressing
The PCM contains proteins responsible for microtubule _______ and __________ including γ-tubulin, pericentrin and ninein.
Nucleation and anchoring.
_______ chromatin forms a 7nm diameter fiber.
Nucleosomal
________________—is a 200bp double-stranded segment of DNA partially wrapped around an eight histone proteins.
Nucleosome
Centrosomes are located just outside the _______.
Nucleus
Mitosis only has how many division cycles?
One
When species are unicellular, the mother cell is judged to be _____ organism, and the two daughter cells are _____ new separate organisms.
One, Two
There is usually _____ centrosome per cell, located near the cell's ________; it doubles during _________, so there are two when the cell divides.
One, center, interphase.
____________ produces a Single Haploid Egg Cell.
Oogenesis
In female animals, oogenesis, the production of egg cells, occurs within specialized diploid (2n) cells of the ovary known as......
Oogonia
Quite early in the development of the ovary, the diploid (2n) _________initiate mitosis to produce diploid (2n) primary oocytes.
Oogonia
Other diploid species, however, have different numbers of chromosomes in their somatic cells. For example, the dog has 39 chromosomes per set (78 total), the fruit fly has 4 chromosomes per set (8 total), and the tomato has 12 per set (24 total).
Other diploid species, however, have different numbers of chromosomes in their somatic cells. For example, the dog has 39 chromosomes per set (78 total), the fruit fly has 4 chromosomes per set (8 total), and the tomato has 12 per set (24 total).
Acrocentric and Submetacentric chromosomes have: P arms: SHORT OR LONG arm Q arms: SHORT OR LONG arms
P arms: short arm Q arms: long arms
He then crossed true-breeding parents to each other........... This is called a ___ _______.
P cross
These true breeding plants are termed the parental generation, or__ ___________.
P generation
Is this PLANT OR ANIMAL Cytokinesis The two daughter cells are separated by the formation of a cell plate. At the end of anaphase, Golgi-derived vesicles containing pectin polysaccharides and carrying other cell wall materials are transported to the equator of a dividing cell.
PLANT
WHAT DO THEY DESCRIBE??? A. chromosomes become even thicker due to even more condensation and chromatids become visible such that the paired bivalents show four chromatids or a tetrad structure. B. Chromosomes move closer in their pairing so that the paired homologs are now 100nm apart or "Synapsed". C. A synaptonemal complex forms between the homologs. D. ________ ________ or genetic recombination between the non-sister chromatids of the paired homologs occurs. This will exchange maternal genetic segments with paternal genetic segments. The process is facilitated by recombinase enzymes within the synaptonemal complex. This event mixes maternal genes and paternal genes ensuring that daughter cells produced by meiosis I will be genetically different from each other and from the original parent cell.
Pachynema Crossing over
Bacterial species are typically unicellular, although individual bacteria may associate with each other to form ______, ______ or_______.
Parts, chains, or clumps.
In animal cells centrosomes have an amorphous mass of protein termed the.......
Pericentriolar material (PCM).
Mendel chose the garden pea, ________ ______, to investigate the natural laws that govern plant hybrids.
Pisum sativum
Centrosomes and centrioles are both found in animal cells but centrioles are NOT found in 99% of........
Plant cells
ASTER/POLAR/KINETOCHORE???? microtubules project into the region between the two poles; they play a role in pole separation and in cell elongation. They help to "push" the poles away from each other
Polar
Mendel was able to pry open immature flowers and remove the anthers before they produced _______ (emasculation). These flowers were now solely female (diecious) and could not self-fertilize.
Pollen
The ovaries of a 12 -13 year old female are filled with millions of these ___________ _______ all suspended at diplonema. When estrogen levels increase during puberty the ovary responds by taking one primary oocyte each month and re-initiating meiosis I -proceeding to diakenesis followed by metaphase I, anaphase I etc....
Primary oocytes
Synthesis of short 10-12 nucleotide RNA Primers via an enzyme called __________ occurs. These strands of RNA primers are synthesized by the linkage of __________. These short RNA strands start, or prime, the process of DNA replication. In the leading strand, a single primer is made at the origin of replication. In the lagging strand, multiple primers will be made. The RNA primers will be eventually REMOVED OR REPLACED.
Primase, ribonucleotides, removed.
"Initial Synthesis" of DNA via DNA Polymerase a (alpha) bound with _________occurs on both lagging and leading strands. DNA polymerase a is responsible for _________ just the first 20-30 nucleotides of the leading and lagging strands off of the 10 nucleotide RNA primer.
Primase, synthesizing
What do they all have in common? a. the centrosomes continue to move to opposite ends of the cell and demarcate two spindle poles, one within each of the future daughter cells. b. Chromatin condenses even further thickening the chromosomes to their most condensed level. c. the nuclear membrane completely disrupts and or disintegrates into vesicles via the phosphorylation of nuclear laminal intermediate filaments which make the nuclear envelope fragment. d. the spindle fibers known as kinetochore microtubules begin to interact with the _________ on the centromeres that bind sister chromatids together. As the end of prometaphase nears, the __________- on opposite sides of a pair of sister chromatid centromere are attached to ________ microtubules from opposite poles. e. sister chromatids undergo jerky movements as they are tugged, back and forth, between the two poles which helps to push and pull the sister chromatids towards the _________ or _________ ________.
Prometaphase Kinetochores Kinetochores Kinetochores equatorial or metaphase plate
At the start of mitosis, in ________, the DNA has already been replicated but is loose and stringy and uncoiled and decondensed.
Prophase
What do they all have in common?? As this phase begins the G2 interphase loose chromatin becomes progessively coiled, folded packaged and condensed into more compact chromosome structures consisting of two sister chromatids that are readily visible by light microscopy. The two centrosomes begin to move apart and as they do they start to generate the mitotic spindle apparatus. the nucleolus becomes less visible.
Prophase
WHAT PHASE DO THEY DESCRIBE?? -Chromatin condensation occurs producing thickened chromatids that become tightly coiled within the nucleus. - A mitotic spindle starts to form within the cell; the microtubules lengthen and the centriole pairs within centrosomes begin to move towards opposite ends of the cell. -The nucleolus begins to fade or disappear. -The cell's nuclear membrane begins to break down. -Microtubules (spindle fibers) attach to each of the chromatids at the kinetichores located on opposite sides of the centromere. -Spindles will push the chromosomes until they are all aligned on the equator or metaphase plate.
Prophase II
During metaphase I pairs of sister chromatids are aligned in a double row rather than a single row, as occurs in mitosis. Furthermore, the arrangement of sister chromatids (dyads) within this double row is __________.
Random
The term _________ is used to describe a variant that is masked by the presence of a dominant trait but reappears in subsequent generations.
Recessive
A. Protist- Chlamydomonas green algae also fuse isogametes in water creating a zygote that secretes a _______ ______here in the enclosure meiosis occurs forming four immature cells that grow into mature cells that normally reproduce mitotically but if conditions become harsh these mature cells change into sperm and. Note the products are not spores and not really gametes until environment changes. No multicellular stage. B. Fungi- neurospora crassa (bread mold) performs meiosis inside of ___________ within ______ structures and produces walled ascospores. Ascospores germinate on food source and give rise to mycelia/hyphae and conidia which are haploid....conidia of opposite mating type can sexually fuse similar to sperm and egg. C. Fungi-Mushroom meiosis takes place in the _________ (mushroom cap) it produces basidiospores. Basidiospores give rise to haploid mycelia-branch like structures found underground. Here instead of two independent cells fusing like sperm and egg. Two cells that are each part of a mycelial branch fuse to create a dikaryon that will produce via mitosis a muticellular dikaryon basidiocarp that rises from underground(mushroom). In the mushroom cap some dikaryon cells in the gills will fuse their nuclei creating a 2n cell that will go through meiosis
Resistant enclosure Asocarps ascus Basidiocarp
The kinetochore is a group of proteins that are bound to the centromere. These proteins help to hold the sister chromatids together and also play a role in chromosome sorting. In what phase?
S Phase
__-_____ or ____ _________ is initiated by the assembly of a pre-replication complex (preRC) composed of many proteins. Six of these proteins form a origin recognition complex (ORC) that act as a first initiator of eukaryotic DNA replication by directly binding to the ARS1 box sequences
S Phase or DNA replication
To test this hypothesis..... Mendel's _____ _____ the plants of the F1 generation (the tall ones)
Self fertilized
After the MCM helicase begins to break the hydrogen bonds between base pairs at the orgin and starts to _______ and ______ the strands; positive supercoiling ahead of each replication fork occurs.
Separate and unwind
Know that.......Eukaryotic Chromosomes Are Inherited in PAIRS, SETS, OR INDIVIDUALLY?
Sets
Mendel conducted the P cross and F1 x F1 cross for all of his _______ ________.
Seven characters
_________ _______ typically requires two organisms and requires gametes such as sperm and eggs. Requires fusion of gametes to form diploid zygotes. The offspring of sexual reproduction are genetically distinct from their parents ...they are not clones.
Sexual Reproduction
For most species, each eukaryotic chromosome contains a ________ _________, which usually appears as a constricted region of a mitotic chromosome connecting two sister chromatids.
Single centromere
The X shaped duplicated structure seen during prophase and prometaphase and metaphase is a ________ _______ made up of two duplicated sister chromatids. The ________ _______ we see during anaphase and telophase are each 1 single chromosome with no duplicate sister chromatids .....just a ________ _______ ________.
Single chromosome, single structures, single unduplicated chromosome
A________________ usually has a few hundred to several thousand different genes
Single eukaryotic chromosome
Chromosomes are compact folded and condensed as _______ structures during anaphase and telophase but exist as compact folded and ____________duplicated structures during ____________ and ____________ and ___________.
Single, condensed, prophase, prometaphase and metaphase.
The two (2) centromere linked-replicated DNA molecules in their condensed state are called...... .
Sister Chromatids
The term _________ _______ can only be used when a chromosome is in its X shaped duplicated structure seen during prophase and prometaphase and metaphase...here it is a _________ ________with two duplicated sister chromatids. These are often called ________-2 chromatids. Once Anaphase separates the sister chromatids by splitting at the centromere......the structures immediately become daughter ____________ (unduplicated-monads) and at that moment there are ZERO..NO...sister chromatids in the cell and there will be none in the cell during telophase or G1 of the next cycle. Once S phase occurs again a new sister will be made
Sister chromatid, single chromosome, dyads, chromosome
Therefore, the term chromosome can refer to either a pair of _______ _________ (a dyad) during G2 and early stages of M phase.
Sister chromatids
On occasion, bacteria can transfer LARGE OR SMALL??? pieces of genetic material to each other, through __________ using a sex pilus structure.
Small, conjugation
Mendel more than likely wondered what happened to the short trait in the F1 and likely may have also reasoned that the short trait might skip a generation. For example Mendels eye color -blue-- was the same as his grandparents—blue-- but not the same as his parents—brown--...his eye color from his grandparents skipped a generation. So maybe LARGE OR SHORT?? plants---that were not present in the F1 at all. would skip a generation and show up in the next round
So maybe short plants
In humans, most _______ cells have 46 chromosomes—two sets of 23 each.
Somatic
In vascular and many nonvascular plants, what type of cells have dispensed with centrosomes altogether.
Somatic cells
What is the shape of chromosomes in bacteria?
Some are circular in bacteria
What is the shape of chromosomes in eukaryotes?
Some are linear in eukaryotes.
The Mitotic Spindle Apparatus Organizes and .........
Sorts Eukaryotic Chromosomes
The majority of eukaryotic genes codes for a __________
Specific cellular proteins
The diploid (2n) primary spermatocyte progresses through meiosis I yielding haploid (n) secondary spermatocytes which enter meiosis II to produce four haploid (n) cells, which are known as.......
Spermatids
The testes contain diploid (2n) _____________ cells that divide by mitosis to produce two cells. One of these remains a diploid _____________ cell, and the other cell becomes a diploid (2n) ___________ _________.
Spermatogonial Spermatogonial Primary spermatocyte
These cells then mature into haploid (n) sperm cells aka......
Spermatozoa
He then obtained pollen from another plant by gently touching its mature anthers with a paintbrush. Mendel applied this pollen to the _________ of the flower that already had its anthers removed.
Stigma
To terminate replication requires that a special polymerase called ______________ replicate the last nucleotide portion of the chromosome to prevent shortening of the ends of chromosomes.
TELOMERASE
Termination of DNA replication in eukaryotes occurs at......
TELOMERES
-The cell elongates even more during this phase. -a nuclear membrane begins to form, from fragments of the parent cell's nuclear membrane, around each set of chromosomes at the poles of the cell. -The chromosomes become less tightly coiled and less apparent or we say the chromosomes decondense back to chromatin. -The nucleoli reappear and the spindle breaks down. The division of genetic material from one nucleus into four different haploid daughters is now almost complete.
TELOPHASE II
In simpler plants, such as mosses, a haploid spore can produce a protenma which generates buds and eventually a large multicellular gametophyte by repeated mitoses and cellular divisions. The gametophyte then produces multicellular gametangia such as antheridia and archegonia. Antheridia produce sperm and archegonia produce eggs. TRUE OR FALSE??
TRUE
The tips of chromosomes called __________ contain tandem repeated sequences and a 3' overhang of 12-16 nucleotides.
Telomeres
They are structures found at the ends of linear chromosomes. They serve several important functions in the replication and stability of the chromosome.
Telomeres
What phase is this?? Opposite of the vents of prophase and prometaphase. -During this phase the chromosomes decondense from their thick folded, coiled, packaged state back to a chromatin state which is loose and stringy and unfolded, and uncoiled. -The nuclear membrane re-forms to produce two separate nuclei. This requires nuclear lamina dephosphorylation via phosphatases. The nucleolus reappears. -The spindle apparatus completely breaks down two diploid daughter nuclei are created by the end of telophase all still contained within one mother cell.
Telophase
After anaphase I: WHAT PHASE IS THIS?? - The nuclear envelope starts to reform around each daughter nuclei. - The chromosomes become less tightly coiled and less apparent or we say the chromosomes decondense back to chromatin. - The nucleoli reappear. - The spindle breaks down. - The division of genetic material from one _______ _______ into two genetically distinct _______ ________ is complete, signaling the end of meiosis I. However, this is not the end of cell division.
Telophase I Diploid nucleus Haploid nuclei
In male animals, spermatogenesis, the production of sperm, occurs within glands known as the.......
Testes
In metaphase I ________ _________ ________ along the 3-D equatorial plane or mid-line plane of a sphere like cell. .
Tetrads are aligned.
The analogy is of "packaging up" the DNA : Let's say you about to move your stuff from your current apartment to a new apartment. To do this in the most efficient manner you go to Lowes and get some large boxes and "Package up" your belongings in to these large boxes. It is much easier to move the large boxes rather than individually moving the 1000s of smaller items within the boxes. The cells DNA is being moved to a new place—a new daughter cell. It is much easier to package up that DNA into a big box—a fully compact 700nm chromosome--- than to move the loose unfolded spread out 7nm nucleosomal DNA
The analogy is this: Let's say you about to move your stuff from your current apartment to a new apartment. To do this in the most efficient manner you go to Lowes and get some large boxes and "Package up" your belongings in to these large boxes. It is much easier to move the large boxes rather than individually moving the 1000s of smaller items within the boxes. The cells DNA is being moved to a new place—a new daughter cell. It is much easier to package up that DNA into a big box—a fully compact 700nm chromosome--- than to move the loose unfolded spread out 7nm nucleosomal DNA
At the molecular level, how similar are homologous chromosomes?
The answer is that the sequence of bases of one homolog would usually differ by less than 1% relative to the sequence of the other homolog. For example, the DNA sequence of chromosome 1 that you inherited from your mother would be greater than 99% identical to the sequence of chromosome 1 that you inherited from your father.
All replication events occurring at the multiple origins of replication result in fork merges along the length of the chromosome at all locations except the _____ ___ _________ which are replicated last.
Tips of chromosomes
An enzyme known as ____________ travels in front of MCM helicase and alleviates positive supercoiling to prevent "DNA tangling.
Topoisomerase
Most species of animals are diploid, and their haploid gametes are considered to be a specialized type of cell. TRUE OR FALSE??
True
Before initiating his cross fertilization studies, Mendel obtained several varieties of peas that were considered to be distinct _______ _______.
True breeders
Know ______ _____ or ____ ______in genetics problems is code for HOMOZYGOUS: A true breeding Tall Pea plant = TT; A true breeding purple flowered pea plant= PP; A true breeding short pea plant= tt; A true breeding green pea plant= yy; A true breeding Yellow pea plant= yy (Yellow=YY-dominant Green=yy-recessive).
True breeding or pure breedingk
For the P cross, both parents are ______ ______ plants. Therefore, each one has identical copies of the height gene. TT......or.......tt
True breeding plants
Mendel began with ______ ______ plants that differed in a single character. Example: ______ _____ Tall Plant and a true breeding Short Plant differ in the Character of Height.
True-breeding
Cells start to divide but can not stop dividing...leading to..........
Tumor formations
Know that... When S phase (DNA replication) is completed, a cell actually has _______ as many chromatids as chromosomes in the G1 phase.
Twice
Humans have how many sets of 23 linear chromosomes?
Two
In the general process for unicellular organisms, a preexisting cell divides to produce ___ new cells—____ new organisms.
Two
Know that.......A diploid cell has _____ sets of chromosomes
Two
_________ _________ are located just outside the nucleus buried within the centrosome.
Two centrioles
Mitosis and cytokinesis ultimately produce _____ ___________ _____having the same number of chromosomes as the mother cell. Barring rare mutations, the two daughter cells are ________ _______ to each other and to the mother cell from which they were derived.
Two daughter cells, Genetically identical
How many origins of replication does bacterial and eukaryotic chromosomes have?
Unlike most bacterial chromosomes, which contain only one origin of replication, eukaryotic chromosomes contain many origins, interspersed approximately every 100,000 bp.
By convention, the __________ letter represents the dominant allele (T for tall height, in this case), and the recessive allele is represented by the same letter in lowercase (t, for dwarf height).
Uppercase
Mitosis was first observed microscopically in the 1870s by the German biologist ________ ________, who coined the term mitosis (from the Greek mitos, meaning thread).
Walther Flemming
The 2n primary oocytes then enter meiosis I prophase I. This occurs while the fetus is still WITHIN THE WOMB/ NOT WITHIN THE WOMB?? of the mother occurring within the embryonic ovaries of the yet to be born progeny.
Within the womb.
WHAT DO THEY DESCRIBE?? A. Characterized by the appearance of _______ which represent the two thicker more condensed homologous chromosomes in their partially condensed state. B. Rough pairing of chromosomes. Homologous chromosomes approach each other and come within 300 nm of each other.
Zygonema Bivalents
M-phase consist of two subdivisions;
a) mitosis b) cytokinesis
In addition to protein coding genes, chromosomes contain three types of regions that are required for chromosomal replication and segregation and stability:
a) origins of replication, b) centromeres c) telomeres
Know the following about homologous chromosomes The two chromosomes in a homologous pair are nearly identical in size—have the same length width etc. The two chromosomes in a homologous pair have the same centromere position which can be: a. __________- centromere is in the middle of the chromosome b. _________- centromere is just below the telomeric end of the chromosome c. ________- centromere is just below or above the middle of the chromosome d. ___________- centromere is at the end of the chromosome
a. metacentric b. acrocentric c. submetacentric- d. telocentric
The seven characters that Mendel studied;
a. plant height, with tall and dwarf variants; Tall Dominant b. flower color, with purple and white variants; Purple Dominant c. flower position, with axial and terminal variants; Axial Dominant c. seed color, with yellow and green variants; Yellow Seed(Pea) Dominant d. seed shape, with round and wrinkled variants; Round aka Smooth was Dominant f. pod color, with green and yellow variants; Green Pod (Fruit) was Dominant g. pod shape, with Inflated and constricted variants. Inflated was Dominant
The goals of Meiosis are:
a. to reduce the species specific diploid chromosome number to the haploid number and thereby ensure species specific diploid number constancy from generation to generation. b. to produce gametes either directly or indirectly via spores. c. to create genetic variability.
The ovaries of a 12 -13 year old female are filled with millions of these primary oocytes all suspended at diplonema. When estrogen levels increase during puberty the ovary responds by taking one primary oocyte each month and re-initiating meiosis I -proceeding to diakenesis followed by metaphase I, _____________ I etc....
anaphase I
The term chromosome can be a bit confusing because it originally meant a.........
distinct structure that is observable with the microscope
The primary purpose of mitosis is to.....
distribute replicated chromosomes, dividing one cell nucleus into two nuclei, so each daughter cell receives the same complement of chromosomes
The ___ _____ ______ arrests and does not go through meiosis II. The __________ _______ begins meiosis II -starting with prophase II and metaphase II at this point in mammals, the haploid (n) secondary oocyte is released from the ovary—an event called __________—and travels down the ______ toward the uterus using cilia propagation. During this journey, if a haploid (n) sperm cell enters the oviduct and penetrates the haploid (n) secondary oocyte, it is stimulated to complete meiosis II—initiating _________ ___- this occurs asymmetrically with the large oocyte-ootid side facing where the sperm penetrated (cytokinesis starts during the onset of ________ ____ to create this size difference creating the larger cell on the sperm penetrating side), then Telophase II occurs creating a haploid nucleus; at this point the large secondary oocyte finishes cytokinesis and produces 2 products a haploid (N) ootid with its own haploid nucleus and a sperm nuclei inside of the ootid as well. The ootid then differentiates into an haploid (n) _______ whose nuclei fuses with the haploid (n) sperm nuclei to form a diploid zygote- The other smaller product of Meiosis II is a _______ ______ _______. The 1st and 2nd polar bodies frequently die via apoptosis and disappear, but in some cases they remain and can be important in the life cycle of the organism. Abnormal asymmetric cytokinesis might lead to twinning if the polar body and ova are both fertilized. .
first polar body Secondary oocyte Ovulation Oviduct Anaphase II Anaphase II Ovum Second polar body
The kinetochore is composed of a group of
flat proteins that link the centromere to the spindle apparatus during mitosis and meiosis specifically to kinetechore microtubules
Therefore, the DNA in a eukaryotic cell must be ________ and _________ by a staggering amount to fit inside the nucleus. Bacteria also compact their chromosomes to fit within the 5µm cell but to a lesser degree than eukaryotes since bacteria have MUCH LESS OR MUCH MORE? DNA to compact.
folded and packaged, much less
Know that.......Gametes (sperm and egg cells or their haploid precursors) are also called ______ ______.
germ cells
b) Bacterial origins include oriC and have_____ and _____ repeats that are AT rich.
have 9 mer and 13 mer
What they have in common? 3. The two chromosomes in a homologous pair have the same banding pattern. 4. The two chromosomes in a homologous pair contain a similar composition of genetic material. 5. If a particular gene is found on one copy of a chromosome, it is also found on the other homolog. However, the two homologs may carry different versions of a given gene, which are called allele. .
homologous chromosomes
During gamete formation these pairs some how uncouple and become individualized within a given gamete. He called this separation property the ______ ____ _______.
law of Segregation
An organelle located in the cytoplasm of all animal cells and some plants, fungi, and protozoa that controls the _______, _______, and _______ ______________ of many of the cell's microtubules throughout the cell cycle.
polymerization, position and polar orientation.
Meiosis I has five phases:
prophase I, metaphase I, anaphase I, telophase I, cytokinesis
Mitosis is subdivided into phases known as........
prophase, prometaphase, metaphase, anaphase, and telophase.
A typical eukaryotic gene is _________________ of base pairs in length.
several thousand to tens of thousands
Meiosis is associated with ______ ________ _______.
sexual reproducing organisms
....A cross in which an experimenter observes one character is called a _____ _____ ______.
single factor cross
In S phase the process of creating a _________ _________involves everything you learned about Eukaryotic Replication.
sister chromatid
Centromeres
sites that link replicated DNA molecules together after the DNA replication phase of the cell cycle...the S phase .
The second step to accomplish greater chromatin compaction is to take nucleosomes and coil them and fold them into 30 nm fibers called.......
solenoids
The third step to accomplish greater chromatin compaction is to take........... This creates chromatin looped fibers that are 300nm in diameter and visible under the light microscope. Figure 10.15 page 251
solenoids and fold them and coil them and then coil those coils again and then loop those coils onto a scaffold of matrix proteins
Each eukaryotic chromosome contains a long, linear DNA molecule that is typically ____________________________in length
tens of millions to hundreds of base pairs
A cylindrical cell structure composed mainly of a protein called _________and found mostly in ___________ ________ ________but not found in 99% of ________ _______.
tubulin, animal eukaryotic cells, plants cells
Each octamer contains: How many copies of histone proteins?
two copies each of four different histone proteins
As shown in Figure 3.2c, for example, a human somatic cell has ______ copies of chromosome 1, _____ copies of chromosome 2, and so forth. Within each pair, the chromosome on the left is a homolog to the one on the right, and vice versa. In each pair, one chromosome was inherited from the mother (maternal homolog) and its homolog was inherited from the father (paternal homolog).
two, two
If an F 1 individual is crossed with another F 1 individual they produce genotypes in the ratio of..... a phenotypic ratio of.......
¼ TT to 2/4 Tt to ¼ tt, ........ from the cross Tt x Tt ¾ tall to ¼ dwarf.