Bio 1030 Clemson Exam 3

Allele

Different forms of a gene

Anaphase

the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles

anchorage dependence

The requirement that to divide, a cell must be attached to a solid surface.

Apoptosis

programmed cell death

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

Autosome

Any chromosome that is not a sex chromosome

benign tumor

An abnormal mass of cells that remains at its original site in the body.

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

Cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division

carcinoma

cancer that arise in external or internal body coverings

cell cycle

series of events that cells go through as they grow and divide

cell cycle control system

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

cell division

reproduction at the cellular level

cell plate

A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

Centromere

Area where the chromatids of a chromosome are attached

Centrosome

A structure in animal cells containing centrioles from which the spindle fibers develop.

Mitotic checkpoint

occurs after metaphase; cell determines whether or not the chromosomes are attached to the spindle and correctly lined up in the middle of the cell

Chiasma

site of crossing over

Chromatid

one of two identical "sister" parts of a duplicated chromosome

Chromatin

the entire complex of DNA and proteins that is the building material of chromosomes

chromosome

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

cleavage furrow

The area of the cell membrane that pinches in and eventually separates the dividing animal cell

crossing over

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

Cytokinesis

Division of the cytoplasm during cell division

Deletion

A change to a chromosome in which a fragment of the chromosome is removed.

density-dependent inhibition

crowded cells stop dividing

diploid cell

A cell containing two sets of chromosomes (2n), one set inherited from each parent.

DNA repair gene

this gene fixes errors made in DNA replication
"spell check"

Down Syndrome

a condition of intellectual disability and associated physical disorders caused by an extra copy of chromosome 21.

Duplication

change to a chromosome in which part of the chromosome is repeated

Euchromatin

a region of DNA that is uncoiled and undergoing active transcription into RNA

Fertilization

Process in sexual reproduction in which male and female reproductive cells join to form a new cell

Gamete

sex cell

G1 stage

first stage in interphase, during which cellular growth and development takes place

G2 stage

third stage of interphase during which organelle replication and protein synthesis takes place

genetic recombination

The regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents.

growth factors

Regulatory proteins that ensure that the events of cell division occur in the proper sequence and at the correct rate.

haploid cell

A cell containing only one set of chromosomes (n).

Heterochromatin

Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed.

Histones

protein molecules around which DNA is tightly coiled in chromatin

homologous chromosomes

Chromosomes that have the same sequence of genes and the same structure

HPV (human papilloma virus)

virus that causes cervical cancer

Interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

Inversion

chromosome rearrangement in which a segment of a chromosome is reversed end to end

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

Leukemia

cancer of white blood cells

life cycle

The generation-to-generation sequence of stages in the reproductive history of an organism.

loci

Location of a gene on a chromosome

lymphoma

malignant tumor of lymph nodes and lymph tissue

malignant tumor

An abnormal tissue mass that can spread into neighboring tissue and to other parts of the body; a cancerous tumor.

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

Metaphase

Chromosomes line up in the middle of the cell

matastasis

the spread of cancer cells from one part of the body to another

Mitosis

part of eukaryotic cell division during which the cell nucleus divides

mitotic phase (M phase)

The part of the cell cycle when the nucleus divides (via mitosis)

mitotic spindle

An assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis.

Nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

Nucleosome

repeating subunit of chromatin fibers, consisting of DNA coiled around histones

Pap test

test for cervical or vaginal cancer

phragmoplast

In dividing plant cells, a structure formed by overlapping microtubules that guide vesicles containing cell wall components to the middle of the cell.

Prometaphase

The second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes.

Prophase

first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus

Proto-oncogenes

the corresponding normal cellular genes that are responsible for normal cell growth and division

sarcomas

Cancers that arise in the connective tissue cells, including bones, ligaments, and muscles.

sex chromosomes

X and Y chromosomes.

sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

sister chromatids

Identical copies of a chromosome; full sets of these are created during the S subphase of interphase.

somatic cells

body cells

Telomerase

An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.

telomerase gene

telomeres shorten after every division... unless the telomerase gene has a mutation and they never shorten, resulting in cancer.

Telophase

After the chromosome seperates, the cell seals off, Final Phase of Mitosis.

tetrad

structure containing 4 chromatids that forms during meiosis

translocation

Change to a chromosome in which a fragment of one chromosome attaches to a nonhomologous chromosome.

Trisomy 21

Down syndrome

tumor

mass of rapidly dividing cells that can damage surrounding tissue

tumor suppressor genes

make proteins that stop cell division and kill cells

Zygote

fertilized egg

ABO blood groups

Genetically determined classes of human blood that are based on the presence or absence of carbohydrates A and B on the surface of red blood cells.

achondroplasia

A form of human dwarfism caused by a single dominant allele; the homozygous condition is lethal

amniocentesis

needle puncture of the amniotic sac to withdraw amniotic fluid for analysis

blending concept of inheritance

parents of contrasting appearance always produce offspring of intermediate appearance

Carrier

A person whose genotype includes a gene that is not expressed in the phenotype.

character

any observable feature, or trait, of an organism, whether acquired or inherited

chorionic villus sampling (CVS)

Prenatal diagnostic technique that involves taking a sample of tissue from the chorion.

chromosome theory of inheritance

A basic principle in biology stating that genes are located on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.

Codominant

Inheritance pattern in which a heterozygote expresses the distinct trait of both alleles.

complete dominance

a relationship in which one allele is completely dominant over another

cross

mating of two organisms

cross-fertilization

process by which sperm from one flower's pollen fertilizes the eggs in a flower of a different plant

cystic fibrosis

A genetic disorder that is present at birth and affects both the respiratory and digestive systems.

dihybrid cross

A cross between individuals that have different alleles for the same gene

Dominant

Describes a trait that covers over, or dominates, another form of that trait.

Duchenne muscular dystrophy

A human genetic disease caused by a sex-linked recessive allele; characterized by progressive weakening and a loss of muscle tissue.

F1 generation

the first generation of offspring obtained from an experimental cross of two organisms

f2 generation

offspring of the F1 generation

Genetics

The scientific study of heredity

Genotype

genetic makeup of an organism

Hemophilia

A hereditary disease where blood does not coagulate to stop bleeding

Heredity

Passing of traits from parents to offspring

Heterozygous

An organism that has two different alleles for a trait