Meiosis and Mutation Vocab. Chapter 10

deletion

A deficiency in a chromosome resulting from the loss of a fragment through breakage; a mutational loss of one or more nucleotide pairs from a gene.

karyotype

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

Chromosomal abnormalities

A missing, extra, or irregular portion of chromosomal DNA. It can be from an atypical number of chromosomes or a structural abnormality in one or more chromosomes.

meiosis

A modefied type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. This results with half the number of chromosome sets as the original set

homologous pairs

A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One homologous chromosome is inherited from the organisms father, the other from the mother. Also called homologs or homologous chromosomes.

Mitosis

A process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. Mitosis conserves chromosomes number by allocating replicated chromosomes equally to each of the daughter nuclei

duplication

An aberration in chromosome structure due to fusion with a fragment from a homologous chromosome, such that a portion of a chromosome is duplicated.

translocation

An aberration in chromosome structure resulting from attachment of a chromosomal fragment to a nonhomologous chromosome

inversion

An aberration in chromosome structure resulting from reattachment of a chromosomal fragment in a reverse orientation to the chromosome from which it originated.

nondisjunction

An error in meiosis or mitosis in which each members of a pair of homologous chromosomes or sister chromatids fail to separate properly from each other.

somatic cells

Any cell in a multicellular organism except a sperm or egg or their precursor

random fertilization

Any possible egg can be fertilized by any possible sperm.

diploid

Containing two complete sets of chromosomes, one from each parent

genetic variation

Differences among individuals in the composition of their genes or other DNA segements.

independent assortment

Formation of random combinations of chromosomes in meiosis and of genes on different pairs of homologous chromosomes by the passage according to the laws of probability of one of each diploid pair.

germ line cells

Gamete cells

genetic recombination

General term for the production of offspring with combinations of traits that differ from those found in either parent.

homologous

Pairing at meiosis and having the same structural features and patterns of genes

spermatogenesis

The continuous and prolific production of mature sperm cells in the testis.

zygote

The diploid cell produced by the union of haploid gametes during fertilization; a fertilized egg

egg

The female gamete

meiosis I

The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosomes as the original cell.

reduction division

The first division of meiosis

sperm

The male gamete

DNA Replication

The process by which a DNA molecule is copied; also called DNA synthesis.

Oogenesis

The process in the ovary that results in the production of female gametes.

crossing over

The reciprocal exchange of genetic material between non-sister chromatids during prophase one of meiosis

meiosis II

The second division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original set

sister chromatids

Two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms. While joined, two sisters chromotids make up one chromosome.. Chromatids are eventually seperated during mitosis or meiosis two.

monosomy

a diploid cell that has only one copy of a particular chromosome instead of a the normal one

trisomy

a diploid cell that has three copies of a particular chromosome instead of the normal two

trisomy X female

a form of chromosomal variation characterized by the presence of an extra X chromosome in each cell of a human female

turners syndrome female

a genetic defect in which women only have one X chromosome, causing developmental abnormalities and infertility

gametes

a haploid reproductive cell, such as an egg or sperm. They unite during sexual reproduction to produce a diploid zygote

down syndrome

a human genetic disease usually caused by the presence of an extra chromosome 21; characterized by developmental delays and heart and other defects that are generally treatable or non-life-threatening

binary fission

a method of asexual reproduction by "division in half." In prokaryotes, binary fission does not involved mitosis, but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process.

budding

a method of asexual reproduction in which a new organism develops from an outgrowth of bud due to cell division at one particular site. The new organism remains attached as it grows, separating from the parent organism only when it is mature leaving behind scar tissue

amniocentesis

a sampling of amniotic fluid used to test for developmental abnormalities in a fetus

Prokaryotic Cells

a type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with prokaryotic cells (bacteria and archaea) are called prokaryotes.

Eukaryotic cells

a type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with eukaryotic cells (protists, plants, fungi, and animals) are called eukaryotes

sexual reproduction

a type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from both parents vie that gametes.

syndrome

extra or missing chromosomes that cause birth defects or miscarriages

Changes in chromosome structure (mutations at the gene level)

many different kinds , deletion, duplication, inversion, and translocation, all resulting in gene mutations

sex chromosomes abnormalities

occurs as a result of chromosome mutations brought on by mutagens or problems that occur during meiosis.

Asexual reproduction

the generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts). In most cases, the offspring are genetically identical to the parent.

trisomy 21

the most common form of down syndrome caused by an extra copy of chromosome 21

genetic testing

the sequences of DNA used to discover genetic ''differences, anomalies, or mutations

fertilization

the union of haploid gametes to produce a diploid zygote

jacob's syndrome male

when a man has an extra sex chromosome (XYY)

klinefelter's syndrome

when males have an extra X chromosome (XXY); results in a tall thin physique, small infertile testes, and enlarged breasts