AP BIOLOGY UNTIT 4 AND 5 VOCAB

Addition Rule

the probability that any one of two or more mutually exclusive events will occur is calculated by adding together their individual probabilities. ("OR")

Alleles

The different forms of one gene.

Anchorage dependence

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

Apoptosis

Programmed cell death involving a cascade of specific cellular events (starting with a chemical signal) leading to death and destruction of the cell.

Binary Fission

type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells

both Binary fission and Mitosis produce

genetically identical daughter cells from their respective parent cells

Cell Cycle Control System

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

Cell Cycle

sequence of events from the production of a eukaryotic cell to the time the cell itself reproduces

Centromere

The region of the chromosome that holds the two sister chromatids together during mitosis

Centrosome

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.

Chromatin

granular material visible within the nucleus; consists of DNA tightly coiled around proteins

Chromosomal inversion(Chromosomal mutation that occurs during crossing over)

Pieces of DNA that broke off to cross over inert upside down

chromosomal Translocation(Chromosomal mutation that occurs during crossing over)

piece of DNA Goes to the wrong chromosome

Chromosome

condensed threads of genetic material formed from chromatin as a cell prepares to divide

Cleavage [Furrow]

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

Crossing Over

process in which homologous chromosomes exchange portions of their chromatids during meiosis

Cyclic AMP

Second messenger made from ATP by adenylyl cyclase, inactivated by phosphodiesterase which converts it to AMP

Cyclin dependent kinases

A protein kinase (enzyme) that is active only when attached to a particular cyclin. Cyclin binds to the kinase during interphase and mitosis, triggering and controlling activities during the cell cycle.

Density Dependent Inhibition

cells stop dividing when they come into contact with one another (crowded cells stop dividing)

Dihybrid

Crosses between individuals that differ in two traits (tracking two traits in a cross)

Dominant Allele

An allele whose trait always shows up in the organism when the allele is present. This allele produces more proteins for its trait than its counterpart does

Down Syndrome

a congenital disorder caused by having an extra 21st chromosome (Trisomy 21); results in a flat face and short stature and mental retardation

Genome

the complete genetic material contained in an individual that makes the individual unique

Genomic Imprinting

a phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent.

Heterozygote

when an organism's genotype has dominent and recessive genes for a trait (ex. Bb)

Homozygote

when an organism's genotype has either both dominant genes for a trait or both recessive genes (ex. BB or bb)

Hormone

signal molecule released into the bloodstream that triggers particular responses

how does cytokineses happen in plant cells?

through the formation of a cell plate. This cell plate, a new cell wall, forms between the two newly divided nuclei

How many alleles are in one genetic locus on a chromosome

2 alleles one from the maternal and one from paternal

How many cells are produced in mitosis

2 diploid cells that are genetically identical. They are clones of the parent cell

How many chromosomes do gametes have

23 chromosomes

How many chromosomes do Somatic cells have

46 chromosomes

How many gametes are formed by meiosis

4 for every diploid cell used

How many pairs of Autosomes Do Humans have

22 pairs

How many pairs of SEX CHROMOSOMES do humans have

1 pair

how many sets of chromosomes does a somatic cell contain

2 sets of chromosome that occur in a homologous pair ( one from female and one from male parent)

how many times is DNA replicated in meiosis

once

independent assortment

process that result in more than one possible arrangement of tetrads in metaphse 1

Karyotype

A picture of all the chromosomes in a cell arranged in pairs

Law of Independent assortment

Mendelian principle stating that genes for different traits are inherited independently of each other (genes of one trait don't interfere with genes of another trait)

Law Segregation

Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair (each parent) is present in each gamete.

Ligand

A signal molecule that binds specifically to a receptor site of another molecule

Linkage Map

A genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes.

Linked Genes

genes located on the same chromosome that tend to be inherited together in genetic crosses

Locus

the specific site of a particular gene on its chromosome

Malignant Tumor

mass of abnormal cells resulting from uncontrolled cancer cell division (can spread throughout the body)

Meiosis is a form of

reductive cell division

Metastasis

spread of cancer cells beyond their original site in the body

Mitotic Spindle

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

Monohybrid

genetic crosses that involve one trait

Monosomy

a condition in a diploid cell in which one chromosome of one pair is missing as a result of nondisjunction during meiosis

Multiplication Rule

A rule of probability stating that the probability of two or more independent events occurring together/simultaneously can be determined by multiplying their individual probabilities. ("AND")

nondisjunction

homologous chromosomes fail to separate at anaphase one
or sister chromatids fail to separate in anaphase two

Polyploidy

condition in which an organism has a full extra set of chromosomes

Protein Kinases

Enzymes that activate or inactivate other proteins by adding a phosphate group to them

Protein Phosphatases

An enzyme that removes phosphate groups from proteins, often functioning to reverse the effect of a protein kinase.

Recessive Allele

an allele that is masked when a dominant allele is present

Recombinant Chromosomes

a chromosome created when crossing over combines the DNA from two parents into a single chromosome

Second Messengers

A small, nonprotein, water-soluble molecule or ion, such as calcium ion or cyclic AMP, that relays a signal to a cell's interior in response to a signal received by a signal receptor protein.

Sex-linked gene

a gene located on a sex chromosome

Signal Transduction Pathway

A series of steps linking a mechanical or chemical stimulus to a specific cellular response.

Sister Chromatid

one of a pair of identical chromosomes created before a cell divides

Trisomy

A genetic condition of having three chromosomes instead of two (an extra chromosome).

True Breeding

describes organisms or genotypes that are homozygous for a specific trait and thus always produce offspring that have the same phenotype for that trait (purebreds)

what are 2 types of asexual reproduction

binary fission and mitosis

What are gametes

Reproductive/sex cells

what are Gametes

Sex cells

What are haploid cells?

Haploid cells have only one copy of each chromosome. Gametes are haploid.

What are oncogenes?

mutated proto-oncogenes which do not produce proper proteins to regulate cell cycle

What are protooncogenes?

Genes that code for cell-cycle regulatory proteins

What are Somatic cells

Cells in the body that are NOT reproductive/Sex cells and are not specialized for reproducing

What are the chromosomal mutations that occur during crossing over

-duplication
-deletion
-inversion
-translocation

what are the errors in meiosis

nondisjunction,aneuploidy

what are the two basic strategies of cell reproduction

asexual reproduction and sexual reporduction

What are tumor suppressor genes?

genes for proteins that stop cell division if conditions are not favorable,When mutated cells override checkpoints

What can animals produce to stimulate cell divisions

growth factors

what causes genetic variation in asexual reproduction

Mutations or changes int he dna sequence due to environmental factors or copying errors

what do prokaryotes use to asexually reproduce

Binary fission

what do single cell and multicellular eukaryotes use to asexually reproduce

mitosis

What does centrosome position determine

The plane of cell division

What does sexual reproduction involve?

involves fusion of gamete

What happens in Anaphase of mitosis?

The chromosomes separate forming chromatids and daughter chromsomes move toward the opposite ends of the cell

What happens in Anaphase one of meiosis?

Kinetochore spindle fibers pull tetrads apart and pull chromosomes to opposite ends of the cell

What happens in cytokinesis in animal cells?

Cell forms cleavage furrow actin and myosin form in the inner surface of the membrane and form contractions to pinch the cell in two

What happens in cytokinesis in plant cells?

The cell plate divides the cytoplasm and forms a cell wall

What happens in G1 phase of interphase

The cell gathers nutrients and synthesizes RNA and protiens for DNA Synthesis and Chromosome replication in the S phase

What happens in metaphase of mitosis?

chromosomes line up on metaphase plate. Chromosomes align at the center of the cell and form the metaphase plate.

What happens in metaphase one of meiosis

-kinetochore spindle fibers drag tetrads onto metaphase plate
and line them up

What happens in prometaphase of mitosis?

sister chromatids become attached to the kinetochore (strandy part of the spindle), which are attached to the centrsome, nuclear envelope breaks

What happens in prophase of mitosis

Nuclear Envelope disappears, Chromosomes or condense, mitotic spindle forms and attach to kinetochores.

what happens in prophase one of meiosis

-mitotic spindle begins to form
nuclear membrane begins to break down
synapsis occurs to form tetrads
crossing over occurs to increase genetic variation

What happens in telophase of mitosis?

-chromosomes uncoil
-spindle fibers disintegrate
-nuclear memberane forms

What happens in telophase one of meiosis

nuclear envelope forms around separated chromosomes
chromosomes decondense
nucleolus reappears

What happens in the G2 phase of the interphase?

Cell creates micro tubules for segregating chromosomes and cell checks its DNA for errors

What happens in the S phase of Interphase

DNA is replicated in the S Phase

What is a centrosome?

an organelle near the nucleus of a cell that contains the centrioles (in animal cells) and from which the spindle fibers develop in cell division.

What is a diploid cell?

A cell with two sets of chromosomes

What is a genetic locus

The location of a particular gene on a chromosome

what is a homolog

pair of chromosomes that carry the same genes one from mother and one from father

What is a sister chromatid?

one half of a duplicated chromosome