Term
| Pairing of homologous chromosomes and crossing over occurs in which phase of meiosis? |
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Definition
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Term
| Meiosis typically results in the production of: |
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Definition
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Term
| During which phase of the cell cycle are chromosomes replicated? |
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Definition
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Term
| Which of the following is the proper sequence for mitosis? |
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Definition
prophase, metaphase, anaphase, telophase
(PMAT) |
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|
Term
| Cells have mechanisms to control: |
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Definition
-cell growth
-DNA replication
-cell division |
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Term
| Various forms of a gene at a given locus are called: |
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Definition
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Term
| Which of the following designates a normal human male? |
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Definition
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Term
| A human X-linked recessive trait may be: |
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Definition
| passed to sons from their mothers |
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Term
| The theory of segregation: |
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Definition
| explains the behavior of a pair of alleles during meiosis |
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Term
| Which of the following indicates homozygous genotypes? |
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Definition
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|
Term
| How do prokaryotic cells reproduce? |
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Definition
| asexually by prokaryotic fission |
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Term
This copies DNA and divides a nucleus, producing two
identical nuclei |
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Definition
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Term
This is a nuclear division that produces haploid gametes for
sexual reproduction |
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Definition
|
|
Term
| A chromosome consists of DNA that is wrapped around ________ and ________ |
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Definition
| proteins (histones); condensed |
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Term
Each histone and the DNA wrapped around it make up a
________, the smallest unit of structural organization in
chromosomes |
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Definition
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Term
A sequence of three stages (interphase, mitosis, and cytoplasmic
division) through which a cell passes between one cell division
and the next |
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Definition
|
|
Term
Consists of three stages, during which a cell
increases in size, doubles the number of cytoplasmic
components, and duplicates its DNA |
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Definition
|
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Term
|
Definition
• G1: Interval of cell growth and activity
• S: Interval of DNA replication (synthesis)
• G2: Interval when the cell prepares for division |
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Term
| Interphase: Most cell activity takes place during __? |
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Definition
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Term
Interphase: Control mechanisms work at certain points in the cell cycle;
some can keep cells in |
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Definition
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|
Term
Mitosis produces __ ____ _______with the same number and kind
of chromosomes as the parent |
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Definition
|
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Term
• A dynamic network of microtubules that forms during nuclear
division
• Grows into the cytoplasm from opposite poles of the cell and
attaches to duplicated chromosomes
• Microtubules from opposite poles attach to different sister
chromatids and separate them |
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Definition
|
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Term
|
Definition
|
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Term
|
Definition
|
|
Term
| What are the four main stages of mitosis? |
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Definition
1)prophase
2)metaphase
3)anaphase
4)telophase
PMAT |
|
|
Term
• Chromosomes condense
• Microtubules form a bipolar spindle
• Nuclear envelope breaks up
• Microtubules attach to the chromosomes |
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Definition
|
|
Term
All duplicated chromosomes line up midway between the spindle
poles |
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Definition
|
|
Term
Microtubules separate the sister chromatids of each chromosome
and pull them to opposite spindle poles |
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Definition
|
|
Term
• Two clusters of chromosomes reach the spindle poles
• A new nuclear envelope forms around each cluster
• Two new nuclei are formed, each with the same chromosome
number as the parent cell |
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Definition
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|
Term
|
Definition
|
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Term
|
Definition
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Term
|
Definition
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Term
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Definition
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Term
|
Definition
|
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Term
|
Definition
|
|
Term
In most kinds of eukaryotes, the cell cytoplasm divides
between late ________ and the end of ________, but the
mechanism of division differs |
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Definition
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|
Term
| The process of cytoplasmic division is called _____________. |
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Definition
|
|
Term
Animal cells:
• A ________ _____ partitions the cytoplasm
• A band of _____ _______ ________ the cell midsection, contracts, and
pinches the cytoplasm in two |
|
Definition
| contractile ring; actin filaments rings |
|
|
Term
Plant cells:
• A _____ _______ forms midway between the spindle poles; it partitions the
cytoplasm when it reaches and connects to the parent cell wall |
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Definition
|
|
Term
________ can activate other molecules to stop the cell cycle or
cause cells to die |
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Definition
|
|
Term
| _______ _______ can activate kinases to start mitosis |
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Definition
|
|
Term
When all checkpoint mechanisms fail, a cell loses control over
its cell cycle and may form a ___________ in
surrounding tissue |
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Definition
|
|
Term
• Abnormal masses of cells that lack control over how they grow
and divide
• Benign neoplasms (such as ordinary skin moles) stay in one place
and are not cancerous
• Malignant neoplasms are cancerous |
|
Definition
|
|
Term
• Cells grow and divide abnormally; capillary blood supply to the
cells may increase abnormally
• Cells may have altered plasma membrane and cytoplasm;
metabolism may shift toward fermentation
• Cells have altered recognition proteins and weakened adhesion;
may break away and invade distant tissues (metastasis) |
|
Definition
| Cancers (malignant neoplasms) |
|
|
Term
_______ ________ produces genetically identical copies of
a parent (clones) |
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Definition
|
|
Term
_______ ________ introduces variation in the combinations
of traits among offspring |
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Definition
|
|
Term
_______ are regions in an organism’s DNA that encode
information about heritable traits |
|
Definition
|
|
Term
| _______ are different forms of the same gene |
|
Definition
|
|
Term
A nuclear division mechanism that precedes cytoplasmic division
of immature reproductive cells in sexually-reproducing eukaryotic
species |
|
Definition
|
|
Term
A ______ ______ has two nonidentical copies of every chromosome
(except XY sex chromosomes) |
|
Definition
|
|
Term
Meiosis in germ cells halves the diploid number of chromosomes
(2n) to the haploid number (n), producing haploid gametes
• Eggs and sperm have 23 unpaired chromosomes |
|
Definition
|
|
Term
The diploid number (23 pairs) is restored at fertilization, when
two haploid gametes fuse and form a diploid _______, the first
cell of a new individual |
|
Definition
|
|
Term
In meiosis, DNA is replicated once and divided twice (meiosis I
and meiosis II), forming _____ haploid nuclei |
|
Definition
|
|
Term
|
Definition
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Term
|
Definition
|
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Term
|
Definition
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|
Term
• The process by which a chromosome and its homologous partner
exchange heritable information in corresponding segments
• Occurs during condensation in prophase I |
|
Definition
|
|
Term
|
Definition
|
|
Term
Diploid bodies with specialized structures that form spores
(haploid cells) that give rise to gametophytes through mitosis |
|
Definition
|
|
Term
A multicelled haploid body inside which one or more gametes
form |
|
Definition
|
|
Term
_______ cells (chromosome number 2n) have pairs of genes on
homologous chromosomes |
|
Definition
|
|
Term
| A ________ is a permanent change in a gene |
|
Definition
|
|
Term
| A ________ has nonidentical alleles for a trait |
|
Definition
|
|
Term
An allele is ________ if its effect masks the effect of a
recessive allele paired with it |
|
Definition
|
|
Term
Garden pea plants inherit ____ “units” of information for a
trait, one from each parent |
|
Definition
|
|
Term
• A method of determining if an individual is heterozygous or
homozygous dominant
• An individual with unknown genotype is crossed with one that is
homozygous recessive (AA x aa) or (Aa x aa) |
|
Definition
|
|
Term
• Testcrosses that check for a dominance relationship between two
alleles at a single locus
• May be crosses between true breeding (homozygous) individuals
(AA x aa), or between identical heterozygotes (Aa x Aa) |
|
Definition
|
|
Term
• Diploid cells have pairs of genes on pairs of homologous
chromosomes
• The two genes of each pair separate during meiosis, and end up
in different gametes |
|
Definition
| Mendel’s law ofsegregation |
|
|
Term
Many genes are sorted into gametes independently of other
genes |
|
Definition
| Mendel’s law of independent assortment |
|
|
Term
• Tests for dominance relationships between alleles at two loci
• Individuals that breed true for two different traits are crossed
(AABB x aabb)
• F2 phenotype ratio is 9:3:3:1 (four phenotypes)
• Individually, each dominant trait has an F2
ratio of 3:1 –
inheritance of one trait does not affect inheritance of the other |
|
Definition
|
|
Term
• Two nonidentical alleles of a gene are both fully expressed in
heterozygotes, so neither is dominant or recessive
• May occur in multiple allele systems |
|
Definition
|
|
Term
• Genes with three or more alleles in a population
• Example: ABO blood types |
|
Definition
|
|
Term
• One allele is not fully dominant over its partner
• The heterozygote’s phenotype is somewhere between the two
homozygotes, resulting in a 1:2:1 phenotype ratio in F2 offspring
Ex) Snapdragon color
• RRis red
• Rris pink
• rris white |
|
Definition
|
|
Term
• Two or more gene products influence a trait
• Typically, one gene product suppresses the effect of another
• Example: Coat color in dogs
• Alleles B and b designate colors (black or brown)
• Two recessive alleles ee suppress color |
|
Definition
|
|
Term
• One gene product influences
two or more traits
• Example: Some tall, thin
athletes have Marfan
syndrome, a potentially fatal
genetic disorder |
|
Definition
|
|
Term
The ________ apart two genes are on a chromosome, the more
often crossing over occurs between them |
|
Definition
|
|
Term
• All genes on one chromosome
• Linked genes are very close together; crossing over rarely occurs
between them |
|
Definition
|
|
Term
• Traits with a range of small differences
• The more factors that influence a trait, the more continuous the
distribution of phenotype |
|
Definition
|
|
Term
When continuous phenotypes are divided into measurable
categories and plotted as a bar chart, they form a bell-shaped
curve |
|
Definition
|
|
Term
The _____ gene on the Y chromosome is the master gene for
male sex determination
• Triggers formation of testes, which produce the male sex
hormone (testosterone)
• Without testosterone, ovaries develop and produce female sex
hormones (estrogens) |
|
Definition
|
|
Term
• A micrograph of all metaphase chromosomes in a cell, arranged
in pairs by size, shape, and length
• Detects abnormal chromosome numbers and some structural
abnormalities |
|
Definition
|
|
Term
A ______ ______ ______ is expressed in homozygotes and heterozygotes
• Tends to appear in every generation
• With one homozygous recessive and one heterozygous parent,
children have a 50% chance of inheriting and displaying the trait
• Examples: achondroplasia, Huntington’s disease |
|
Definition
| dominant autosomal allele |
|
|
Term
_______ _______ _______ are expressed only in homozygotes; heterozygotes are carriers and do not have the trait
• A child of two carriers has a 25% chance of expressing the trait
• Example: galactosemia |
|
Definition
| Autosomal recessive alleles |
|
|
Term
Most __________ disorders do not follow simple patterns of Mendelian inheritance
• Depression, schizophrenia, bipolar disorders |
|
Definition
|
|
Term
X chromosome alleles give rise to phenotypes that reflect
________ patterns of inheritance |
|
Definition
|
|
Term
More ______ than _______ have X-linked recessive genetic disorders
• Males have only one X chromosome and can express a single
recessive allele
• A female heterozygote has two X chromosomes and may not
show symptoms |
|
Definition
|
|
Term
| DNA sequences are repeated two or more times; may be caused by unequal crossovers in prophase I |
|
Definition
|
|
Term
Loss of some portion of a chromosome; usually causes serious
or lethal disorders
• Example: Cri-du-chat |
|
Definition
|
|
Term
Part of the sequence of DNA becomes oriented in the reverse
direction, with no molecular loss |
|
Definition
|
|
Term
Typically, two broken chromosomes exchange parts (reciprocal
translocation) |
|
Definition
|
|
Term
| Too many or too few copies of one chromosome |
|
Definition
|
|
Term
| Three or more copies of each chromosome |
|
Definition
|
|
Term
• Changes in chromosome number can be caused by
__________, when a pair of chromosomes fails to separate
properly during mitosis or meiosis
Ex)
• Monosomy (n-1 gamete)
• Trisomy (n+1 gamete) |
|
Definition
|
|
Term
• A standardized chart of genetic connections
• Used to determine the probability that future offspring will be
affected by a genetic abnormality or disorder |
|
Definition
|
|
Term
A rare or uncommon version of a trait; not inherently life
threatening |
|
Definition
|
|
Term
An inherited condition that causes mild to severe medical
problems, characterized by a specific set of symptoms (a
syndrome) |
|
Definition
|
|
Term
• Starts with parental genotypes, pedigrees, and genetic testing for
known disorders
• Information is used to predict the probability of having a child
with a genetic disorder |
|
Definition
|
|
Term
| Three types of prenatal diagnosis |
|
Definition
• Amniocentesis
• Chorionic villus sampling (CVS)
• Fetoscopy |
|
|
Term
(widespread, routine testing for alleles associated with genetic disorders)
• Provides information on reproductive risks
• Identifies family members with a genetic disorder
• Used to screen newborns for certain disorders
• Used to estimate the prevalence of harmful alleles in a
population |
|
Definition
|
|
