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193 Cards in this Set

  • Front
  • Back

Meiosis can occur in the:

a. toes

b. hair follicle

c. ovaries

d. digestive tract


What happens during S phase?

a. DNA replication

b. cell is doing its thing

c. error-checking

d. cellular division

DNA replication

Cell division is not complete once Mitosis is over. There is still one more phase that has to happen.

True or False


One chromosome #8 from Mom and one chromosome #8 from Dad are together called:

Homologous Pair

A human cell that has only one full set of chromosomes (23) would be called:


The name of the protein that the spindles attach to is:


In Metaphase of Mitosis:

a. chromosomes split apart

b. chromosomes move to the middle

c. nuclear membrane reforms

d. chromosomes duplicate

Chromosomes move the middle

G1, S & G2 are together called:

a. mitosis

b. meiosis

c. growth phase

d. interphase


Spindle fibers attach to the chromosomes at the centrosome.

True or False


Coat color in Labrador retrievers is controlled by alleles on two genes: This is an example of:

a. Dominance

b. Incomplete dominance

c. Codominance

d. Epistasis

e. Pleiotropy


An allele whose effect masks the effect of other alleles is called:


When Mendel crossed a white flower (pp) with a purple flower (PP), the offspring (Pp) were all purple. What is the fancy biology word for those offspring, since they have two different alleles?

Heterozygous and F1

After Mendel did di-hybrid crosses, he found new combinations of traits in the second-generation offspring that didn't look anything like the parental. This led to his theory of:

a. Segregation

b. Parent-offspring disequivalency

c. Independent assortment

Independent assortment

For pea color, green is dominant to yellow. If a heterozygous plant is crossed with a yellow pea plant, what is the likelihood that the offspring will have yellow peas?

a. 0

b. 1/4

c. 1/2

d. 3/4

e. 100%


For human blood types, A is dominant to O and B is dominant to O, but A & B are ____________ to each other:

a. Recessive

b. Dominant

c. Incompletely dominant

d. Codominant


Can there be human genes that are typically possessed by males but not females?

a. Yes, genes that are on the X chromosome are typically possessed by only males.

b. No, all genes in the human genome are typically possessed by both sexes.

c. Yes, genes that are on the Y chromosome are typically possessed by only males.


When pairs of chromosomes do not properly separate during Meiosis, we call this:



All calico cats are female because...

a. The calico coloration pattern is a result of Barr body formation.

b. The males die during embryonic development

c. The Y chromosome has a gene blocking orange coloration


The X chromosome carries a gene for "femaleness".

True or False


A person who has trisomy for the X-chromosome will be phenotypically ________ and will also be ___________.

a. Male; normal

b. Male; sterile

c. Female; normal

d. Female; sterile

Female; Normal

Colorblindness is an X-linked recessive disorder. If a man who is colorblind has kids with a woman who is not colorblind (not a carrier), what is the likelihood that their MALE offspring will be colorblind?

a. 0%

b. 25%

c. 50%

d. 75%

e. 100%


Robert disease is an autosomal recessive disorder. If two carriers have children, what is the likelihood that their offspring will have Robert disease?

a. 0%

b. 25%

c. 50%

d. 75%

e. 100%


Buchwald disease is autosomal dominant. If a man with the disease (heterozygous) has kids with a woman that does not have the disease, what is the likelihood that their offspring will have the disease?

a. 0%

b. 25%

c. 50%

d. 75%

e. 100%


How do most prokaryotes, including bacteria, divide?

Asexually, called "Binary Fission"

How do Eukaryotes divide?

Mitosis and Meiosis

During prokaryotic cell division, first ____________, then _____________

copy the DNA; Divide

After prokaryotic cell division, each daughter cell is ___________________ of the parent cell

Genetically Identical

Multicellular organisms depend on cell division for:



Growth & Division

Tissue Renewal

Why do cells divide?




1. Reproduction

2. Repair

3. Growth

The life of a cell from the time it is first formed from a dividing parent cell until its own division into 2 daughter cells.

The cell cycle

The entire complex of DNA & proteins that is the building material of chromosomes.

Long, loosely-wrapped strand of DNA & various proteins.


DNA molecules are packaged into these super condensed structures


All body cells except the reproductive cells

Somatic cells

Differences between Mitosis vs. Meiosis

6 each

1. Somatic Cells vs. Reproductive Cells

2. 1 split: 2 daughters vs. 2 splits: 4 daughters

3. Daughter cells are diploid vs. haploid

4. No crossing over vs. crossing over

5. No tetrad vs. tetrad

6. Anaphase-Sister chromatids pulled apart vs. homologous pairs in Anaphase 1

Interphase of the cell cycle includes:

G1, S phase, and G2

In G1, what happens?

Main growth phase, organelles duplicate, cell stuff, DNA is chromatin

In S phase, what happens?

DNA replication, no cell stuff, "cell takes a break"

In G2, what happens?

Second growth phase, error checking, cell stuff

In the nuclei of human somatic cells, each contain _______ chromosomes, made up of 2 sets (mom & dad) of _________

46; 23

Fertilized egg


Reproductive cells (eggs & sperm)


After replication: Joined copies of the original chromosome, each containing identical DNA information

Sister chromatids

Before replication: Each chromosome is composed of two single DNA molecules, one from mom and one from dad

Similar but slightly different

Homologous pair

2 complete sets of chromosomes


1 set of chromosomes


The middle part of a chromosome where sister chromatids attach to each other


You can tell a cell has been through S phase by identifying:

Sister chromatids

Chromatin wraps around proteins called...


The "magnets" that give rise and shoot out microtubles.

Sub cellular region containing material that functions throughout the cell cycle to organize the cells microtubules


Begins to form during Prophase, consists of microtubules and associated proteins

Network of microtubules that attach to the chromosomes

Mitotic spindle

The division of the genetic material in the nucleus, nuclear division


"Fishing-line" that pushes and pulls the chromosomes during Mitosis/Meiosis


Protein protector on centromere where spindles attach


The steps of Mitosis are:








Chromosomes form, nuclear envelope dissolves, spindle begins to form, centrosomes start to move towards opposite poles


Spindles attach to Kinetochores


Centrosomes now at opposite poles of the cell, chromosomes line up in the middle (metaphase plate).


Sister chromatids are pulled to opposite poles of the cell.


Spindles are depolymerized, nuclear envelopes begin to form.


Division of cytoplasm, becomes 2 new daughter cells.


A cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle.

Cell cycle control system

How is cell growth controlled?


Control point where stop & go-ahead signals can regulate the cycle. Register inside & outside of the cell


Where crowded cells stop dividing

Density-dependent inhibition

To divide, they must be attached to a substratum (inside of culture jar or the extracellular matrix of a tissue)

Anchorage dependence

Cell "decides" to divide, primary point for external signal influence

G1 checkpoint

Cell makes a commitment to mitosis, assesses success of DNA replication

G2 checkpoint

Cell ensures that all chromosomes are attached to the spindle

M checkpoint

Cancer cells __________ exhibit density-dependent inhibition


Unrestrained, uncontrolled growth of cells, failure of cell cycle control


The transmission of traits from one generation to the next (also called inheritance)


The scientific study of heredity and hereditary variation


Parents endow their offspring with coded information in the form of hereditary units genes. Program the specific traits that emerge as we develop from fertilized eggs into adults.

Section of DNA thats heritable


A single individual is the sole parent and passes copies of all its genes to its offspring without the fusion of gametes.

asexual reproduction

2 parents give rise to offspring that have unique combinations of genes inherited from the 2 parents. Offspring vary genetically from their siblings and both parents

Sexual reproduction

The generation-to-generation sequence of stages in the reproductive history of an organism, from conception to production of its own offspring

Life cycle

XX and XY

Sex chromosomes

All chromosomes besides sex chromosomes are called...


The human life cycle begins when a haploid sperm from the father fuses with a haploid egg from the mother, this union of gametes, culminating in fusion of their nuclei is called...


The resulting zygote after fertilization is _________ because it contains 2 _________ sets of chromosomes bearing genes representing the maternal and paternal family lines.

Diploid; haploid

Made up of Meiosis and fertilization

Sexual life cycle

____________ undergoes Meiosis to __________, _____________ then join to make offspring

Diploid; haploid; haploid

In sexually reproducing organisms, gamete formation involves this type of cell division. Reduces the number of sets of chromosomes from 2 to 1 in the gametes, counterbalancing the doubling that occurs at fertilization. Each human sperm and egg is haploid (n=23)


Meiosis > _____________ > _____________....

Fertilization; Mitosis

Meiosis 1 separates _____________ chromosomes


When does synapsis (tetrad) occur in Meiosis?

Prophase 1

3 unique events to Meiosis in Meiosis 1:




Synapsis and crossing over

homologous pairs at the metaphase plate instead of sister chromatids

separation of homologs instead of sister chromatids

Both sets of sister chromosomes from each homologs are all closely associated


Features of Meiosis include:




Meiosis includes 2 rounds of division

Synapsis (tetrad

Independent assortment of homologous chromosomes

Chromosomes coil tighter and become visible. Synapsis between paired homologs, forms tetrad. Crossing over happens between non-sister chromatids. Centrosome movement to opposite poles, spindle-formation, nuclear envelope breakdown

Prophase 1

Pairs of homologous chromosomes are arranged on metaphase plate. Microtubules attached at kinetochores.

Metaphase 1

Homologs separate, sister chromatids remain attached

Anaphase 1

2 diploid cells form; each chromosome still consists of 2 sister chromatids

Telophase 1

No _____________ _______________ occurs between Meiosis 1 and Meiosis 2

chromosome duplication

Separates sister chromatids after homologs

Meiosis 2

Sister chromatids (not genetically identical) move towards opposite poles

Anaphase 2

Nuclei form, chromosomes de condense, and cytokinesis occurs. Now have 4 daughter haploid cells

Telophase 2

The 3 mechanisms that contribute to the genetic variation arising from sexual reproduction are....

Independent assortment, crossing over, and random fertilization

Random orientation of pairs of homologous chromosomes at Metaphase 1

Independent Assortment of chromosomes

Produces recombinant chromosomes, individual chromosomes that carry genes (DNA) derived from 2 different parents. Genetic recombination between non sister chromatids in a tetrad. Allows the homologs to exchange chromosomal material. Begins in early stage of Prophase 1

Crossing over

In humans, each male and female gamete represents 1 of 8.4 million possible chromosome combinations. The fusion of an egg and sperm during fertilization will produce a zygote of about 70 trillion diploid combinations

Random Fertilization

In metaphase 1, orientation of each pair of homologs on the spindle is __________ making it the second level of ______________

Random; recombination

In anaphase 1, _________________ of maternal and paternal chromosomes occur. Third level of __________________

Independent Assortment; recombination

After Telophase 1, sister chromatids are....

no longer identical because of crossing over

Failure of chromosomes to move to opposite poles during either meiotic division. Pairs of chromosomes do not separate properly.


Non-disjunction leads to ___________ gametes


Gametes with missing or extra chromosomes. Improper chromosome numbers

Aneuploid gametes

The most common cause of miscarriage in humans is....


A heritable feature that varies among individuals


Each variant for a character


Varieties that, over many generations of self-pollination, had produced only the same variety as the parent plant. (Mendel example)


Crossing of 2 true-breeding varieties


True-breeding parents

P generation

P generations hybrid offspring

F1 generation

F1 self-pollinates or cross-pollinates with other F1 hybrids

F2 generation

Father of modern genetics, monk/scientist, 7 years- 29,000 pea plants, rediscovered early 1900's, info was ignored for decades.

Gregor Mendel

Type or form of a gene


Two copies of same allele


Two non-identical alleles


Allele whose effect masks effect of other alleles.


Allele whose effect can be masked by other alleles


The 2 alleles for a heritable character segregate (separate from each other) during gamete formation and end up in different gametes. No telling which allele will be passed on

Law of Segregation

Homozygous is ____________

True-breeding, PP or pp

Heterozygous is not ____________

True-breeding, Pp

An organisms appearance/observable traits: Purple flower or white flower


Which two alleles? genetic makeup: Purple allele P vs. white allele p


While doing punnet squares, the most important generation to look at is the....

F2 generation

4 tenets of Mendels Model:





1. Alleles account for variations in characters, which are called "traits"

2. For each character, organisms inherit 2 alleles: one from each parent

3. If the alleles on homologous chromosomes differ (heterozygous), the dominant allele determines the appearance.

4. Law of Segregation

Monohybrid crosses formed Mendels law of...


Dihybrid crosses formed Mendels law of...

independent assortment

Each pair of alleles segregates independently of each other pair of alleles during gamete formation. Traits are not linked*

The law of independent assortment

Segregation and assortment lead to...

genetic variation

"Mendelian" automatically codes for...

Dominant and recessive

The phenotypes of the heterozygous and the dominant homozygote are indistinguishable

Complete dominance

A third, intermediate phenotype results from flowers of the heterozygotes having less of something than the homozygote. Not totally dominant, phenotype is in-between effect of two homozygous conditions. Carnation example

Incomplete dominance

2 alleles each affect the phenotype in separate, distinguishable ways. Effects of both alleles are expressed. Blood type example


Blood type A, B, AB, and O are...




In blood type AO, ____ is expressed


In blood type AB, they are ____________


In blood type BO, _____ is expressed


When a dominant allele coexists with a recessive allele in a heterozygote, they....

don't actually interact at all

An inherited disorder in humans, which inhibits the metabolization of certain lipids. These lipids accumulate in the brain cells to cause seizures, blindness, and degeneration of motor and mental performance. Dies within a few years, only children that inherit 2 copies of the TS allele (homozygous) have the disease. Mutation on chromosome 15. High among Jews from central-europe

Tay-sachs disease; autosomal recessive.

1 phenotypic expression of 2 genes, labrador example. B/b - how much melonin, E/e - melanin in fur or not.


To get a black fur lab, you would need....

BbEe or BBEE

To get a brown fur lab, you would need...


To get a yellow fur lab, you would need...

_ _ ee

A gene with multiple phenotypic effects, these alleles are responsible for cystic fibrosis, marfan syndrome, and sickle cell disease. Effected heavily by environmental influences. Issues in human genetic disorders.


Autosomal dominant disease, FBN1 on chromosome 15, causes disproportionately long limbs and digits, speech disorders, vision problems, collapsed lung, aorta heart problems.

Marfan Syndrome

Several genes affect phenotypic outcome, usually influenced by the environment, spectrum of phenotypes. Indicated by quantitative variation; an additive effect of 2 or more genes on a single phenotypic character. Height and skin color as example.

Polygenic Inheritance

Affects nerve cell protein, expansion mutation, neurodegenerative dementia, morbidity high after reproductive age. A degenerative disease of the nervous system, is caused by a lethal dominant allele that has no obvious phenotypic effect until the individual is about 35 to 45 years old. 1 out of every 10,000 in US are affected.

Huntington's Disease; Autosomal Dominant

Most people with an autosomal dominant disease will be _______________, ________________ is even MORE rare

heterozygous, homozygous

Extreme premature aging, non-inherited mutation on LMNA gene, improper nuclear envelope- "blobular", impairs cell division and protein synthesis, error in making eggs or sperm.

Progeria; autosomal dominant

Examples of Autosomal dominant diseases are...

Dwarfism, Huntington's disease, Progeria

Cysts and Fibroids in pancreas, CFTR gene on chromosome 17, persistent lung infections, poor growth, overly thick mucus, movement of water and ions in and out of cells, leads to multiple pleiotropic effects.

Cystic Fibrosis; autosomal recessive

Two copies of abnormal gene must be present (homozygous), carriers with no symptoms, inbreeding. Cultural background is a factor.

Autosomal recessive disorders

Examples of autosomal recessive diseases are...

Albinism, cystic fibrosis, sickle-cell, tay-sachs, ellis-van creveld syndrome

Most common inherited disorder among African descendants, 1 out of every 400, caused by substitution of 1 amino acid in the hemoglobin protein of red blood cells, club and clog blood vessels, the 2 alleles are codominant.

Sickle-cell disease; autosomal recessive

Many genes, affect production of melanin


Type of fetal testing, extraction of amniotic fluid with needle


Type of fetal testing, extraction of placenta tissue with a tube.

Chorionic Villus Sampling

Geneticists collect information about a families history for a particular trait and assembles this info into a family tree describing the traits of parents and children across the generations.


Sex-determining gene is called.... (codes for boy)

SRY gene

A gene located on either sex chromosome

Sex-linked gene

Those located on Y chromosome, because there are so few of these genes, there are very few disorders that are passed on. Only 78.

Y-linked genes

The human X chromosome contains approximately 1,100 genes

X-linked genes

Fathers pass X-linked alleles to...

all of his daughters but none of his sons

Mothers can pass X-linked alleles to...

both daughters and sons

Far more ______ than _______ have X-linked recessive disorders

males; females

Various levels of cognitive impairment, characteristic eye shape and facial features. 1/700, result of extra chromosome on 21, increased risk to birth child with this disorder with maternal age.

Trisomy 21; Down-Syndrome

Low rate of survival, serious internal organ and structural disorders, extra chromosome on 18, increased risk to birth child with this disorder with maternal age.

Trisomy 18; Edwards Syndrome

All monosomy disorders...

result in a miscarriage, always die.

Change in chromosomal structure, occurs when a chromosomal fragment is lost, missing certain genes


Change in chromosomal structure, repeats a segment


Change in chromosomal structure, reverses a segment within a chromosome


Change in chromosomal structure, moves a segment from 1 chromosome to a non-homologous chromosome


An example of a duplication disorder is...

Fragile X

On chromosome 5, form of deletion disorder, genes important for cerebral development, difficulty swallowing, cognitive and motor delays.


In each female cell, 1 X chromosome is turned off and is condensed into a barr body, ensures an equal expression of genes from the sex chromosomes even though females have 2 X chromosomes and males have only 1, females heterozygous for genes on the X chromosome are genetic mosaics

X inactivation

Mosaic, either X from mom or either from dad gets inactivated, always female, creates different colored fur. Heterozygous on X, one gets inactivated.

Calico Cats

If disease-carrying gene is on X or Y, will affect ratio of males to females who are affected, can be dominant or recessive, but mostly recessive

Sex-linked diseases

Disease-causing gene on X chromosome, almost all are recessive, woman are usually the carriers while more men than women are affected

X-linked disorder

Some examples of X-linked disorders are...

hemophilia, color-blindness, Duchenne muscular dystrophy

The disease where blood cannot properly clot is called...


The disease where there altered structure of light receptors in the eye, 7-10% of males are affected.


The disease where there's no dystrophin to support muscle cells, in a wheelchair by 12 and respiratory failure in the mid-20's.

Duchenne Muscular Dystrophy

Very few because of few genes on it, every male in a lineage would be affected, genes on it are important for proper sperm morphology

Y-linked disorders

Type of sex chromosome aneuploid disease that makes you short, infertile, no secondary sexual characteristics, neck webbing, and are phenotypically female

X0- Turners Syndrome

Type of sex chromosome aneuploid disease that causes being overweight, tall, feminizing effects, infertile, phenotypically male

XXY- Klinefelter syndrome

This sex chromosome aneuploid makes you male and normal.


This sex chromosome aneuploid makes you female and normal, 2 bar bodies and x inactivation

Trisomy XXX; can also be XXXX

The largest risk factor of genetic disorders for non-disjunction is....

maternal age

The largest risk factor of genetic disorders for autosomal recessive is...

cultural background