Unit IV: Cell Division, Genetics, and Biotechnology

Vocabulary flashcards covering cellular division, Mendelian and non-Mendelian genetics, ancestry, molecular biology, and biotechnology based on Unit IV lecture notes.

Reproduction

The creation of new individuals from existing ones; one of the characteristics of life.

Asexual reproduction

The production of offspring from one parent, resulting in offspring that are genetically identical to the parent.

Sexual reproduction

The production of offspring from two parents through the fusion of gametes, leading to genetic variation and adaptability.

Mitosis

Cell division where a cell makes an exact duplicate of itself for growth or the repair of damaged, infected, or worn-out cells.

Meiosis

The type of cell division that occurs when producing gametes, such as eggs and sperm.

Daughter cells

The name given to the cells produced by the process of cell division.

Parent cell

The name given to a cell that undergoes division to produce daughter cells.

Diploid number

The number of chromosomes found in body cells, designated as $2n$; in humans, this number is 46.

Haploid number

Half the diploid number, designated as $n$; in humans, this number is 23 and is found only in eggs and sperm.

Interphase

The state of a cell's existence most of the time where it performs necessary tasks and makes a copy of each chromosome.

Chromatid

One of the two identical copies of a replicated chromosome.

Prophase

The first phase of mitosis where chromatin condenses into visible chromosomes, the nuclear envelope breaks down, and spindle fibers form.

Metaphase

The phase of mitosis where chromosomes line up along the center and spindle fibers attach to the centromere of each chromosome.

Anaphase

The phase of mitosis where sister chromatids are pulled apart to opposite poles of the cell.

Telophase

The phase of mitosis where chromosomes arrive at opposite poles, decondense into chromatin, and the nuclear envelope reforms.

Cytokinesis

The final stage of cell division where the cytoplasm divides, resulting in two separate cells.

Crossing over

A process in Prophase I of meiosis that results in a different combination of alleles, leading to variation or diversity within a species.

Homologous pairs

Pairs of chromosomes containing one paternal copy and one maternal copy.

Karyotype

An analytical tool and photographic representation of chromosomes arranged in order from largest to smallest to assess chromosomal abnormalities.

Nondisjunction

An error where homologous chromosomes fail to separate during meiosis I or sister chromatids fail to separate during meiosis II.

Down syndrome

The most common trisomy involving three copies of the same chromosome, resulting in specific facial characteristics and shorter stature.

Heredity

The passing of characteristics from parents to offspring via genes.

Dominant traits

Traits that mask or cover up other traits, represented with capital letters.

Recessive traits

Traits that are masked by dominant ones and are presented by lowercase letters.

Allele

A copy or variation of a gene that can be passed from a parent.

Homozygous

An individual inheriting two of the same allele from both parents.

Heterozygous

An individual inheriting two different alleles from its parents.

Genotype

The specific alleles present in an individual.

Phenotype

The physical appearance or what an individual looks like as a result of their alleles.

Punnett Square

A device used to determine the probability of the genotype and phenotype of offspring.

Carrier

An individual who inherits one recessive allele for a disease and one dominant allele that masks it.

Pedigree

A tool useful for determining the inheritance pattern for a specific allele, where females are circles and males are squares.

Incomplete dominance

An inheritance pattern where neither allele is completely dominant, resulting in an intermediate phenotype in heterozygotes.

Multiple allelism

When a single gene has more than two alleles in the gene pool, such as the human ABO blood group system.

Codominance

An inheritance pattern where both alleles are fully expressed in heterozygotes, resulting in a joint phenotype like AB blood type.

Polygenic traits

Traits influenced by multiple genes, typically recognized by a normal bell curve distribution, such as skin color or height.

Sex-linked traits

Traits coded for on sex chromosomes, such as red/green color blindness, which cannot be passed from father to son.

Mitochondrial DNA (mtDNA)

Extranuclear DNA inherited directly from the mother, used to trace maternal lines back approximately 200,000 years.

Nucleotides

The individual building blocks of DNA, each containing a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases.

Codon

A group of three nucleotides along one side of a DNA or RNA strand that codes for one amino acid.

Transcription

The process of copying a gene's DNA sequence into mRNA, which occurs in the nucleus.

Translation

The process of converting mRNA into a sequence of amino acids to form a protein, which occurs in the cytoplasm.

Mutation

A change to the sequence of DNA within a coding region that alters the DNA bases.

DNA Fingerprint

A unique DNA pattern of an individual, also known as a DNA profile, created using short tandem repeats (STRs).

Gel electrophoresis

A process where DNA fragments are separated by size to form bands that make up a DNA profile.

Genetic counseling

A process providing information and support to help individuals understand risks, make medical decisions, and plan for the future regarding genetic conditions.

Transgene

A gene or genetic material transferred naturally or by genetic engineering techniques from one organism to another.

Gene replacement therapy

A medical application where a virus is used to integrate a correct copy of a gene into the DNA of a person with a genetic disorder.

Bioremediation

Using genetically engineered organisms to clean up environmental pollutants, such as oil spills.

CRISPR-Cas9

A genome editing technology that allows genetic material to be added, removed, or altered at particular locations in the genome.

Genome

The complete set of genetic material (DNA) in an organism, including all of its genes and non-coding sequences.