Bio 111 Genetics

Allele

A version of a gene that are produced by a mutation.

Sex-linked traits

Characteristics that are influenced by genes on the sex chromosomes.

Female and Male Sex Symbols

XX-female, XY-male

Heterozygous

An organism that has two different alleles for a trait.

Homozygous

An organism that has two identical alleles for a trait.

Homologous Chromosome

Chromosomes that have the same length, appearance, and Copies of genes, although the alleles may differ.

Pathogenesis

The manner in which a disease develops.

Genotype

The genetic makeup of an organism.

Phenotype

A phenotype is a physical or behavioral trait that an organism expresses that often involves an interaction of the environment with the genotype. The arctic fox is an example of this because their coats change to white in the winter time to help them blend in with the snow and in the summer time it turns back to brown for camouflage. The temperatures and time(photoperiod) change them by affecting the gene expression.

Dominant Alleles

An allele whose trait always shows up in the organism when the allele is present.

Recessive Alleles

Alleles that show their effects only when both alleles are the same

Heterozygosity

The presence of two different alleles at a particular gene locus

Gene

A segment of DNA on a chromosome that codes for a specific trait

Mutation

A random error in gene replication that leads to a change

Mitosis

Cell division in which the nucleus divides into nuclei containing the same number of chromosomes. Interphase, PMAT, Cytokeneisis

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms. Interphase, PMAT 1, Cytokinesis, PMAT 2, Cytokenesis

Binary Fusion

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

Genome

The complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

Conjugation

In bacteria, the direct transfer of DNA between two cells that are temporarily joined.

Pila

Acts as a trapdoor that closes the aperture of the shell when the soft part of the animal is withdrawn.

Plasmid

A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome.

Codominance

Condition in which neither of two alleles of a gene is dominant or recessive. Both are expressed

Indirect heritance

When an individual's phenotype is influenced by genetic variation in conspecifics

Direct inheritance

The transmission of genes from parent to offspring

Nuclear genome

The complete set of DNA within the nucleus of any organism

Karyotype

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

Mitochondrial genome

In eukaryotic cells, the DNA in the mitochondria.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Prokaryotes

Cells that do not contain nuclei (bacteria and archaea)

Eukaryotes

Organisms made up of one or more cells that have a nucleus and membrane-bound organelles. ANIMALS, PLANTS, PROTISTS, FUNGI

Zygote

Fertilized egg

Incomplete dominance

A situation in which one allele is not completely dominant over another allele

Linked Traits

How two genes that are located close to each other on a chromosome are often inherited together.

PMAT

Prophase, Metaphase, Anaphase, Telophase

PMAT 2

Two haploid cells with replicated chromosomes divide in half, forming four haploid cells. Prophase, Metaphase, Anaphase, Telophase repeated

Somatic cells

Any cells in the body other than reproductive cells

Chromosome

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

Gametic cells

Reproductive cells (sperm and egg)

Crossing over

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

Diploid

An organism or cell having two sets of chromosomes or twice the haploid number

Haploid

An organism or cell having only one complete set of chromosomes.

Tetraploid

Four sets of chromosomes

Octoploid

8 sets of chromosomes

Polygenic

Trait controlled by two or more genes

Allele frequency

Number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene.

Base pair probability,

Get independent probabilities. .25, .25, .25, .25. Multiply them together.

Triploid

3 sets of chromosomes