Chromosome Flashcards
_______are structures within livin g cells that contain the g enetic material._____ are physically located within chromosomes
Chromosomes
Genes
each chromosome contains a very long segment of____, which is the g enetic material, and p roteins, which are bound to the DNA and p rovide it with an or g anized structure.
DNA
In eukar y otic cells, this com p lex between DNA and p roteins is called_____
chromatin
Bacteria and archaea are referred to as______, from the Greek meanin g “______,” because their chromosomes are not contained within a membranebound nucleus of the cell.
Prokaryotes
prenucleus
usually have a single type of circular chromosome in a re g ion of the cytoplasm called the_____
Prokaryotes
nucleoid
, from the Greek meanin g “______,” include some sim p le s p ecies, such as sin g le-celled p rotists and some fun g i ( such as y east ) , and more com p lex multicellular s p ecies, such as p lants, animals, and other fun g i.
Eukaryotes
true nucleus
In addition to the nucleus, certain or g anelles in eukar y otic cells contain a small amount of their own DNA. These include the________, which p la y s a role in ATP s y nthesis,
mitochondrion
is the field of g enetics that involves the microsco p ic examination of chromosomes.
chromosomal com p osition of a p articular cell.
Cytogenetics
For eukar y otic s p ecies, this is usuall y accom p lished b y observin g the______ as the y are found in activel y dividin g cells.
chromosomes
When a cell is p re p arin g to divide, the chromosomes become more ti g htl y coiled, which shortens them, thereb y increasin g their diameter. The conse q uence of this shortenin g is that distinctive sha p es and numbers of chromosomes become____ with a li g ht microsco p e.
visible
An or g anized re p resentation of the chromosomes within a cell is called a _______
It reveals how man y chromosomes are found within an activel y dividin g somatic cell.
Karyotype
e do g has ____ chromosomes p er set ( 78 total ) , the fruit fl y has___ chromosomes p er set ( 8 total ) , and the tomato has___ p er set ( 24 total )
39
4
12
When a s p ecies is di p loid, the members of a p air of chromosomes are called________ ; each t yp e of chromosome is found in a ________
Homologs
Homologous pair
the two homologs may carry different versions of a g iven g ene, which are called______.
alleles
T or F
The X and Y chromosomes are not considered homolo g ous chromosomes, thou g h the y do have short re g ions of homolo gy .
TRUE
They are not homologs
An individual carr y in g these two homologous chromosomes is______ for the dominant allele of g ene A, which means that both homolo g s carr y the same allele.
homozygous
The individual is______, Bb, for the second g ene, meanin g that the homolo g s carr y different alleles.
Heterozygous
The p h y sical location of a g ene is called its
locus (p lural: loci ) .
are structures that contain the enetic material, which is DNA.
Chromosomes
______ cells are sim p le and lack cell com p artmentalization, whereas ______cells contain a cell nucleus and other comp artments ( see Fi g ure 2.1 ) .
Prokaryotic
Eukaryotic
One purpose of cell division is __________. In this p rocess, a preexistin g cell divides to p roduce two new cells.
By convention, the ori g inal cell is usuall y called the mother cell, and the two new cells are the dau g hter cells.
When species are unicellular, the mother cell is j ud g ed to be one individual, and the two dau g hter cells are two new se p arate or g anisms.
Asexual reproduction
_________is how bacterial cells p roliferate. In addition, certain unicellular eukar y otes, such as the amoeba and baker’s y east ( Saccharom y ces cerevisiae ) , can reproduce______
Asexual reproduction
Another p ur p ose of cell division is_______ . S p ecies such as p lants, animals, most fun g i, and some p rotists are derived from a sin g le cell that has under g one re p eated cell divisions.
multicellularity
bacteria re p roduce b y a p rocess called
binary fission.
Prior to division, the chromosome re p licates to p roduce two identical co p ies. These two co p ies se g re g ate from each other, with one co py g oin g to each dau g hter cell.
Binary fission
Binar y fission is an______ form of re p roduction because it does not involve g enetic contributions from two different g ametes. On occasion, bacteria can exchan g e small p ieces of g enetic material with each other.
asexual
The DNA found in these or g anelles is referred to as__________, DNA to distin g uish it from the DNA that is found in the cell nucleus.
extranuclear, or extrachromosomal
the strikin g similarities between homolo g ous chromosomes do not a pp l y to the p air of_____ chromosomes. These chromosomes differ in size and g enetic com p osition.
sex chromosomes XY
. A p rotein called_____ assembles into a rin g at the future site of the se p tum. _____ is thou g ht to be the first p rotein to move to this division site
FtsZ
is the main com p onent of microtubules, which p la y a ke y role in chromosome sortin g in eukar y otes.
tubulin
Both _________form structures that p rovide cells with or g anization and p la y ke y roles in cell division.
FtsZ and tubulin
are structures that contain the g enetic material, which is DNA.
Chromosomes
are simple and lack cell com p artmentalization, whereas
Prokaryotic cells
contain a cell nucleus and other comp artments
eukaryotic cells
Chromosomes can be examined under the microsco p e. An or g anized re p resentation of the chromosomes from a sin g le cell is called a
Karyotype
In______, the chromosomes are found in sets.
In eukaryotic species
Eukaryotic cells are often diploid, which means that each t yp e of chromosome occurs in a____\
homologous pair
Bacteria divide b y
binary fission
To divide, eukar y otic cells advance through
cell cycle
Prior to cell division, eukaryotic chromosomes are replicated to
form
sister chromatids
