Dhameja BIOL 101 Exam 3

Interphase

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

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

S phase

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

G2 phase

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

M phase

The phase of the cell cycle that includes mitosis and cytokinesis

Mitosis

Division of the nucleus

Karyokinesis

Technical term for mitosis

Cytokinesis

Division of the cytoplasm

Cell cycle control system

Allows or denies cells to carry on the next stage, regulated by internal and external signals

G1, G2, M

Three major checkpoints in the cell cycle

G1

Checkpoint where cell size, nutrients, growth factors, and DNA damage are checked; if the cell received all the necessary things from the mother cell or not

G2

Checkpoint checking whether internal components are correctly replicated; cell size and DNA replication

M

Checkpoint where spindle assembly the focus

Down syndrome

Condition caused by spindle fiber failure to detach from chromosomes correctly + lack of cell arrest

G0 phase

A nondividing state occupied by cells that have left the cell cycle; a quiescent phase

Apoptosis

Process of programmed cell death

Cyclin CDK complex

Class of protein that acts an internal signal to the cell

CDK

Cyclin-dependent kinases

Arrests

If Cyclin CDK complexes do not form, then the cell _____

Maturation Promoting Factor (MPF)

A protein complex required for a cell to progress from late interphase to mitosis. Cyclin CDK complex

Growth factors

May be food or nourishment, stimulates the cells to grow; lack thereof causes cell to go into conservation instead of dividing

Density dependent inhibition (DDI)

Inhibition by density and overcrowding; when there is no more room for cells then cell division will not occur

Tumor

Formed by mutated cells which ignore DDI by growing vertically as horizontal space is filled

Anchorage dependence

Cell's need for an anchor to remain in place for it to grow and divide

Substratum

Foundation cells use in anchorage dependence

Transformation

Process in which normal cells are converted into cancerous ones

Tumor

Cancer cell mass of abnormal cells

Benign

Tumor that remains at the original site

Uninhibited cell proliferation

1st clause of being a cancer

Metastatic spread

2nd clause of being a cancer

Easy extremities

Where benign tumors are typically found; more difficult to invade these surrounding spaces

Malignant

Tumor that invades surrounding tissues

Softer tissues

Where malignant tumors are typically found; extremely easy to invade these tissues

Metastasis

The spread of cancer cells beyond their original site

Secondary tumor

Cancerous tumor that spread from another part of the body to a new part of the body; can be multiple

Primary tumor

Initial tumor

Cancer

Aggregation of several genetic diseases

Mutated, tumor, cancer

Progression of cells into becoming cancer (list states, not a process)

Cancer cells

Show higher rates of mutation, chromosomal abnormalities, and genomic instability

Mutation

Alteration in a DNA sequence

Stem cell

Undifferentiated cell

Cancer stem cell hypothesis

Rare population of tumor cells while proliferating ends up giving rise to certain cancer stem cells

Cancer stem cells

Have been found to possess ability for unchallenged growth, resistance, and recurrence, and by doing so are able to undergo self-renewal

Age-related cancer

Indication that cancer in a cell develops from the accumulation of several mutagens over a period of time

Protease

Protein breaking enzymes

Caspases

Responsible for initiating apoptosis and digesting intracellular components; proteases

Proto-oncogene

Gene whose products promote cell growth and division; needed for proper functioning of a cell

Tumor suppressor gene

Play a role in regulating cell-cycle checkpoints and initiation of apoptosis

Oncogenes

Mutated proto-oncogenes which contribute to the development of cancer

One

Only _____ allele(s) of proto-oncogenes need to be mutated to contribute to cancer

ras

Proto-oncogene that encodes signal transduction molecules associated with the cell membrane; regulate cell growth and division

Constant division

Occurs when ras is converted to an oncogene and freezes it into its active confirmation

p53

Tumor-suppressor gene that encodes nuclear proteins which act as transcription factors for more than 50 genes

Rise

_____ in expression of p53 gene can arrest cell cycle at several phases

Decrease

_____ in expression of p53 gene may cause cells to be unable to arrest at cell-cycle checkpoints or enter apoptosis in response to damage

6x

Asbestos exposure makes people _____ more likely to develop lung cancer

11x

Being a smoker makes people _____ more likely to develop lung cancer

Cell division

Process using karyokinesis and cytokinesis

Allele

Describes the property or version of a gene

Genome

All of an organism's genetic material

Histones

Protein molecules around which DNA is tightly coiled in chromatin

Diploid

Cell with 2 sets of chromosomes

Haploid

Cell with 1 set of chromosomes

46

Diploid number in humans

23

Haploid number in humans

Somatic cells

All body cells except for gametes and germ cells

Germ cells

Only found in gonads and the only cells which undergo meiosis to create gametes

Gametes

Reproductive cells (sperm and egg)

Zygote

Fertilized gametes, use mitosis to grow

Homologous chromosomes

Two chromosomes in a pair; each pair includes one chromosome from each parent

Similar

Homologous chromosomes are _____

Sister chromatids

Identical chromosomes that are exactly the same

Locus

Specific location of a gene on a chromosome

Mitosis

Cell division that produces identical daughter cells

Meiosis

Cell division that produces 4 unique daughter cells called gametes

Fertilization

Union of gametes (sperm + egg)

Gametes

The only cell produced by meiosis rather than mitosis

Germ

The only cell to undergo meiosis

Prophase

Phase when chromatin condenses into chromosomes and they are first visible

Metaphase

Phase when chromosomes line up in the diameter of the cell

Anaphase (Mitosis)

Phase where sister chromatids separate and move towards opposite ends of the cell (state mitosis or meiosis I/II)

Telophase

Phase where daughter nuclei are at opposite ends of the cell and nuclear division is complete; separation of chromosomes already occurred

Late telophase

When cytokinesis is underway

Centrosomes

Region where spindle fibers/microtubules are attached at the end of the cell

Centromere

Area where chromosomes are attached

Prophase I

Phase when crossing over occurs

Crossing over

Process in which homologous chromosomes exchange portions of their chromatids during meiosis; contributes to genetic variation

Anaphase I (Meiosis)

Phase when homologous chromosomes separate and are moved to opposite ends of the cell (state mitosis or meiosis I/II)

Telophase I

Phase when first nuclear division is complete in meiosis

Prophase II

Phase when chromosomes are already visible and prepare themselves to move to metaphase plate

Anaphase II

Phase when non-identical sister chromatids separate and move to opposite ends of the cell (state mitosis or meiosis I/II)

Telophase II

Phase when second nuclear division is complete in meiosis

4

At the end of meiosis, there are _____ non-identical daughter cells

Independent assortment of chromosomes

In this process, each pair of chromosomes assorts itself independently of other pairs

Recombinant chromosomes

Chromosomes that carry genes from each parent, result of crossing over

Gregor Mendel

Father of modern genetics, discovered basic principles of heredity

Pea plants

What Mendel experimented with

Flower color

Most commonly studied aspect of Mendel's pea experiments

True breeding

Plants that produce offspring of the same variety when they self-pollinate (PP or pp)

Hybrid

Offspring who receives two different traits from two different parents for each character the parents have (Pp)