Biology 1 - Fall 2011 = Chap 9+10

Flashcards For MGCCC 2011 Fall Biology 1 Class - Chapters 9+10
 
Created Nov 1, 2011
by 24psmith
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One of the characteristics of living things is their ability to ... ?
Reproduce their kind
Heredity is the transfer of biological information from ... ?
Parent to offspring
Genetics is the branch of biology concerned with the structure, transmission, and ... ?
Expression of hereditary information
Genes are the ... ? 
Units of heredity 
Chromosomes (colored bodies) are the nuclear packages in which ... ?
Genetic information is stored
Chromosomes are composed of a tangle of darkly staining fibers called ... ?
Chromotins
Chromotin is composed of ... ?
60% protein, 35% DNA, and 5% RNA
THe length of DNA in a single cell nucleus is estimated to be ... ?
About 1 yard
Each chromosome contains .... ?
Thousands of genes
Each gene is a unit of information which determines a specifically hereditary trait and occupies...
Specific location on a chromosome
Some genes are capable of transmitting their chromosomal ... ?
DNA information to RNA molecules
RNA molecules contain the code sequence of amino acids (the building blocks of proteins) of...
Within the organism
Humans have ... ?
About 75,000 genes
Everyy individual in a given species possesses a specific number of chromosomes. These chromosomes...
Virtually every cell of the body.
Human body cells have 46 chromosomes. For this reason 46 is termed the ... number?
Somatic
The somatic number is also identified as the ... number?
Diploid number (2n)
The number of chromosomes present in the sex cells gametes) is 23. This is the ... number ?
Haploid number (1n)
The number of chromosomes between animal species varies from 2 to several hundred (The crayfish...
Also have 46 chromosomes
Once cells reach a certain size, they must stop growing or divide. However, some cells do not...
Nerve cells, cardiac muscle cells, and mature red blood cells (RBCs)
The cell cycle includes all the activities of the cell during which it is ... ?
Actively growing and dividing
The completing of the cell cycle is termed .... ?
Generation time
The time to duplicate an average cell is ... ?
About 24 hours
The cell cycle is divided into ... ?
Four phases
In the M (mitosis) phase, active cell division occurs and lasts about .... ?
1-2 hours
In the G1 (gap 1) phase, organelles begin to double in number and this phases lasts about......
8-10 hours
In the S (synthesis) phase, the DNA replicates and this phase lasts about ... ?
6-8 hours
In the G2 (gap 2) phase, synthesis of proteins occurs  and this phases lasts about ......
4-6 hours
Mitosis occupies approximately ... ?
5% of the total cell cycle
Cell duplication involves ... ?
2 main processes 
Mitosis (greek for threads) is a division of the nucleus that produces an equal sharing of...
2 resulting cells
Cytokinesis is the division of the cytoplasm that is ... ?
Coincident with mitosis
The 5 phases of mitosis are ... ?
Interphase, Prophase, Metaphase, Anaphase, and Telophase.
What's the first phase of mitosis?
Interphase
What's the second phase of mitosis?
Prophase
What's the thirdphase of mitosis?
Metaphase
What's the fourth phase of mitosis?
Anaphase
What's the five phase of mitosis?
Telophase
Interphase is the normal working phase of the clel. Structures and substances such as organelles...
Synthesized and accumulated
Does any cell division take place during Interphase?
NO
Interphase lasts about 95% of the cell cycle and the chromatin in the nucleus is "unorganized"....
Visible
In prophase, the nuclear membrane and .... disappear?
Nucleolus
In Prophase, the chromatin begins to "organize" by coiling and folding and becoming...
Chromosomes become visible
During organization in Prophase, the chromosomes, which duplicated during the S-phase of the...
Sister chromatids
Prophase: The constructed part of the chromosome that joins the sister chromatids is...
A centromere
Prophase: Each sister chromatid has a long or short arm which extends from the centromere....
"p" and the long arm by "q".
In animal cells, the centrosome, and the two centrioles contained within it, duplicate and...
The centrosome is.
Prophase: As each pair of centrioles migrate to their respective poles, they pull one set of...
Termed the kinetochore
Microscopically, the centrioles and their associated microtubules somewhat resemble starbursts...
Called asters (stars) 
During aster formation the chromosomes begin to organize along the ... ?
Center (equator) of the cell
The appearance of the 2 asters, with their microtubules radiating to the cell's equator, is...
The mitotic spindle
Metaphase: The chromosomes line up along the equator of the cell with the centromeres...
The equators midline
Metaphase: The mitotic spindle is complete. SPindle fibers can be seen to run from the...
Centromere on the equator
Metaphase: The chromosomes are very distinct and are ... ?
Used for genetic studied at this stage
Anaphase: Sister chromatids separate at their centromeres. At this point they become...
Independent chromosomes.
Anaphase: The separated chromosomes are pulled to opposite poles by their ... ?
Attached spindle fibers
Anaphase: Anaphase ends when all the chromosomes have ... ?
Reached the poles
Telophase: The chromosomes begin to uncoil to form ... ?
Chromatin threads
Telophase: The spindle ... ?
Dissolves
Telophase: The nucleolus ... ?
Reappears
Telophase: The cytoplasm divides forming the two daughter cells with the ... ?
Return to interphase
Cytokinesis: Cytokinesis is the division of the cytoplasm in .... ?
The formation of daughter cells
Cytokinesis: It begins during ... ?
Telophase
Cytokinesis: A cleavage furrow forms--the precursor of the cell membrane. This...
Each with a new complete nucleus
Cytokinesis: In plants, a cell plate forms which is ... ?
Part of the cell wall
Mitosis: Each replicated cell receives exactly the same chromosomes .... ? 
As the original cell
Mitosis: The cytoplasmic organelles are evenly distributed during cytokinesis and...
Replicate by themselves
Mitosis is ... , not sexual.
Asexual
The daughter cells are exact clones ... ?
Of the original cell
The significance of meiosis is to half the number of chromosomes during gamete formation (......
To maker smaller
Involves .... ?. There are 2 parents.
Sexual reproduction
Each parent contributes a specialized sex cell (hamete). The gamete is ... ?
Haploid (1n).
The male gamete is the ... ?
Spermatozoon (sperm)
The female gemete is the ... ?
Ovum (egg)
Gemetogenesis is the development of gametes and occurs ... ?
In the gonads
Male gonads are ... ?
Testes
Female gonads are ... ?
Ovaries
During fertilization, the sperm and egg fuse to form a zygote (2n). Subsequent divisions ......
Are diploid.
The net effect of meiosis is to provide the offspring with the ... ?
Genetic background of both parents
The chance of combinations of these haploid gametes can result in zygote configurations (mutations)...
Survive; and the bad do not.
There are two cell divisions, but the chromosomes are only duplicated once. In mitosis there...
One duplication of chromosomes 
All the resulting cells are ... ?
Haploid (1n)
In a diploid somatic (body) cell, chromosomes ... ?
Occur as pairs
Each set of chromosomes is a homologous pair and each member is a ... ?
Homologous chromosome or homologue or chromatid.
One member of the homologous pair was inherited from the female parent; the ... ?
Other was inherited from the male parent.
Homologues look alike. THey have the same length, centromere position, and ... ?
Banding patterns.
A specific location on one homologue contains the same gene that occurs at the same location...
Homologue.
First meiotic division: this phase is also called meiosis 1 or .... ?
Reduction division
Prior to meiosis 1, DNA replication occurs forming 2 sister chromatids for ... 
Each chromosome
During meiosis 1, homologous chromosomes come together and line up on the equator side by side....
Synapses
In synapsis, the two sets (pairs) of homologous chromosomes are ... ?
Described as  tetrads or bivalents
Crossing-over .... ?
Occurs at this point
Nonsister chromatid arms cross each other at various points in a .... ?
Seemingly arbitrary fashion
The points where the arms cross are termed chiasmata (singular: chiasma), and serve as junctures...
That of its sister chromatid.
Because of crossing-over, the genetic instructions from a father and a mother are mixed, and...
Chromosomes with recombined genes.
Crossing over increases genetic ... ?
Variability
The homologues of each tetrad separate and move to opposite poles. The centromeres remain intact,...
They do not cleave
Cytokinesis separates the 2 daughter cells ... ?
Which are now haploid
Second meiotic division. This phase is also called ... ?
Meiosis II or equatorial division
No replication of chromosomes .... ?
Occurs at this stage
The centromeres cleave (separate) releasing the 2 sister chromatids, each of which migrates...
To an opposite pole
Cytokinesis separates the 2 sister chromatids which then ... ? 
Develop into haploid gametes
Genetic recombination insures that offspring have a different combination of genes than their...
1) Crossing-over of nonsister chromatids, 2) Independent assortment of homologous chromosomes,...
What's the first mechanism?
Crossing-over of nonsister chromatids
What's the second mechanism?
Independent assortment of homologous chromosomes
What's the third mechanism?
Fertilization results in combinations of genetically different gametes
Crossing-over of ... ?
Nonsister chromatids
Independent assortment of ... ?
Homologous chromosomes
Independent assortment of homologous chromosomes: Independent alignment of tetrads at the equator...
Different combinations of chromosomes
Comparison of meiosis to mitosis: DNA replication takes place only once during both meiosis...
Only one during mitosis
Comparison of meiosis to mitosis: Four daughter cells (gametes) are produced by meiosis. Mitosis...
Two daughter cells
Comparison of meiosis to mitosis: The four gametes formed by meiosis are hapoid. The daughter...
The parental cell (mother cell)
Comparison of meiosis to mitosis: The four daughter cells from meiosis are not genetically...
To the mother cell
Meiosis occurs in the gonads during spermatogenesis and ... ? 
Oogenesis in humans
Oogenesis occurs in the ... ?
Ovaries
Spermatogenesis occurs in the ... ?
Testes
A primary spermatocyte, with 46 chromosomes, divides by meiosis to form two secondary spermatocytes...
23 duplicated chromosomes
Secondary spermatocytes divide to produce four spermatids ... ?
Also with 23 daughter chromosomes
Spermatids then differentiate ... ?
Into motile sperm
Meiotic cell division in mals always results in ... ?
Four cells that become sperm
Unlike the four sperm produced from a single primary spermatocyte, only one ovum is generated...
Site within the uterus.
A priamry oocyte, with 46 chromosomes, divides by meiosis to form two cells, each with ......
23 duplicated chromosomes
One of the cells, a secondary oocyte, receives ... ?
Most of the cytoplasm
The other cell,  a polar body (the first polar body), is ... ?
Discarded and disintegrates
A secondary oocyte begins meiosis II, but then temporarily stops to undergo ovulation, which...
Release from the ovary
The ovum enters the oviduct (Fallopian tube) where fertilization by a ... ?
Sperm may occur
If a sperm enters the secondary oocyte, the oocyte is activated to continue meiosis II ......
Through to completion
Another polar body (the second polar body) is ... ?
Generated and discarded
The result of fertilization is mature diploid cel termed a zygote which becomes the .... ?
First diploid cell of a new individual
Mitosis comes from the Greek word mitos which means ... ?
Threads
What process occurs in organisms that reproduce asexually? 
Mitosis
 What process is absolutely necessary for sexual reproduction to occur?
Meiosis
Eukaryote DNA molecules have large amounts of ______________ dispersed among the DNA molecules.
Proteins
Each chromosome contains thousands of ... ?
Genes
Define chromosomes: 
Colored bodies containing genetic information
Define chromatid:
Concentrated form of a chromatin
Define sister chromatid:
Homologous pair
A chromatin is the chromosome in the ... ?
Nucleus
Chromatids that are attached at the Centromere are called what kind of chromatids?
Sister
Define centromere:
Centromere is the constricted part of the chromatin that joins the sister
Centromere joins duplicated DNA molecules that are called ... ?
Sister chromatids
Centromere position along the chromosome will not be in the exact location for every chromosome...
Varies
Microtubules attach to the kintochore of ... ?
Centromeres
Is a centromere permanent or temporary?
Temporary
Centromere is the attachment site for ... ?
Spindle fibers
What makes spindle fibers?
Microtubules
Different organisms have different number of chromosomes.  Some organisms have as many...
1000
All members of the same species will have the same ______________________ of chromosomes
Number 
The number of chromosomes remains  ?   throughout a life cycle
Constant
List in proper sequence the stages of Mitosis
Prophase, Metaphase, Anaphase, Telophase (PMAT)
In which stages of mitosis does each chromosome consist of two DNA molecules?
Prophase and Metaphase
Chromatids detach from one another and become visibly separate chromosomes during what...
Anaphase and Telophase
New nuclei are formed during what stage of mitosis?
Telophase
Are homologous chromosomes paired during mitosis?  (yes/no)
Yes and No (wth?)
In .... ? ... chromosomes align at the spindle equator (think stages of mitosis)
Metaphase
In .... ? ... sister chromatids become individual chromosomes  (think stages of mitosis)
Anaphase
In .... ? ... centromeres divide (think stages of mitosis)
Prophase (not completely sure about this)
In .... ? ... chromosomes move apart  (think stages of mitosis)
Anaphase
In .... ? ...  spindle microtubules shorten, pulling chromosomes toward the...
Anaphase
Chromosomes are duplicated during  ?  of the cell’s life cycle
Interphase
Plants have a rigid cell wall which prevents the plant cell from being pinched in two. Instead...
Cell-plate
Chromosomes (containing DNA and carrying genes) replicate during _____ of the cell cycle
Mitosis
Chromosomes condense and microtubular spindle develops during this phase of mitosis ... ?
Prophase
During what stage of mitosis does homologous pairs of chromosomes line up on the equatorial...
Metaphase
At this stage of mitosis sister chromatids joined at their centromeres are attached to spindle...
Metaphase
During this phase of mitosis the centromeres break apart as the separated sister chromatids...
Anaphase
Cytokinesis occurs at the end of  ________
Telophase
New daughter nuclear membranes form during this phase of mitosis. _____
Telophase
Spindle fibers are about 25nm in diameter and are formed from ______
Microtubules
Physical separation of the cytoplasm occurs during ________
Cytokinesis
_____ move to opposite poles and form spindle fibers
Centrioles
. Two sister chromatids are joined at the ___________
Centromere
Chromosome name changes during its life cycle from chromatin to chromatid.  What name...
Sister-chromatid
Sexual reproduction results in new combinations of genetic _____
Traits
If meiosis did NOT occur in sexually reproducing organisms, the chromosome number would...
Increase
Through ________________________, offspring are provided with new gene combinations
Meiosis
Through meiosis, parental DNA is divided and distributed to forming gametes.  This results...
Haploid number
Meiosis allows alternate forms of genes to be _____ This enables offspring to have a new...
Shuffled
Different, or alternative, forms of the same gene are called ______
Alleles
In meiosis, each gamete receives one member of each pair of homologous chromosomes and...
Gametes
Homologous chromosomes are in pairs, one chromosome from each pair comes from the father...
Mother
Homologous chromosomes may exchange parts during ____________ of meiosis
Crossing-over (prophase1 )
Crossing over alters the composition of chromosomes and results in new combinations of  ___________...
Alleles
Crossing over is one of the most important events in meiosis because it produces new arrays...
Alleles
 If a diploid organism has a genome consisting of 3 chromosomes, it can produce ________...
8
The haploid number for human chromosomes is ____.  The diploid number is _____.  Altogether...
23,46,92
spermatogonium is ... ?
Diploid
 primary spermatocyt ... ?
Diploid
 secondary spermatocyte ... ?
Haploid
spermatids ... ?
Haploid
oogonium ... ?
Diploid
primary oocyte ... ?
Diploid
secondary oocyt ... ?
Haploid
ovum ... ?
Haploid
polar bodies ... ?
Haploid
Polar bodies do ________________ develop into a gamete
Not
A pine tree is called a sporophyte because it produces spores by (mitosis or meiosis?)
Meiosis

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