Human Heredity: Principles and Issues

A set of vocabulary flashcards derived from lecture notes on Human Heredity, focusing on key genetic terms and definitions.

Genetics

The scientific study of heredity.

Trait

Any observable property of an organism.

Gene

The fundamental unit of heredity and the basic structural and functional unit of genetics.

DNA

A helical molecule consisting of two strands of nucleotides that is the primary carrier of genetic information.

Homozygous

Having identical alleles for one or more genes.

Heterozygous

Carrying two different alleles for one or more genes.

Phenotype

The observable properties of an organism.

Genotype

The specific genetic constitution of an organism.

Dominant trait

The trait expressed in the F1 (or heterozygous) condition.

Recessive trait

The trait unexpressed in the F1 but re-expressed in some members of the F2 generation.

Segregation

The separation of members of a gene pair from each other during gamete formation.

Independent assortment

The random distribution of genes into gametes during meiosis.

Epistasis

The interaction of two or more non-allelic genes to control a single phenotype.

Codominance

Full phenotypic expression of both members of a gene pair in the heterozygous condition.

Incomplete dominance

Expression of a phenotype that is intermediate to those of the parents.

Gametes

Haploid cells produced from germ cells during meiosis that unite during fertilization.

Meiosis

The process of cell division during which one cycle of chromosomal replication is followed by two successive cell divisions to produce four haploid cells.

Cell cycle

The sequence of events that takes place between successive mitotic divisions.

Mitosis

Form of cell division that produces two cells, each of which has the same complement of chromosomes as the parent cell.

Cytokinesis

The process of cytoplasmic division that accompanies cell division.

Pedigree analysis

The construction of family trees and their use to follow the transmission of genetic traits in families.

Mendelian inheritance

The inheritance of traits as determined by allele segregation and independent assortment.

Alleles

One of the possible alternative forms of a gene.

Chromatid

One of the strands of a duplicated chromosome, joined by a single centromere to its sister chromatid.

Chromosome

The threadlike structures in the nucleus that carry genetic information.

Cystic Fibrosis

A genetic disorder caused by mutations in the CFTR gene that affects the respiratory and digestive systems, leading to thick mucus production.

Huntington's Disease

A neurodegenerative genetic disorder caused by mutations in the HTT gene, characterized by progressive movement and cognitive decline.

Sickle Cell Anemia

A genetic blood disorder caused by a mutation in the HBB gene, resulting in abnormal hemoglobin that deforms red blood cells into a sickle shape.

BRCA Genes

Genes that, when mutated, increase the risk of breast and ovarian cancer; BRCA1 and BRCA2 are the most well-known examples.

Nondisjunction

An error in cell division that results in gametes with an abnormal number of chromosomes, leading to conditions like Down syndrome.

Incomplete Dominance

A form of inheritance in which the phenotype of a heterozygote is intermediate between those of the homozygotes.

Codominance

A genetic scenario where both alleles contribute to the phenotype, as seen in AB blood type where both A and B antigens are present.

Linked Genes

Genes that are located close to each other on the same chromosome and tend to be inherited together due to reduced recombination.

Translocation

A chromosomal abnormality where a segment of one chromosome is transferred to another chromosome, potentially disrupting gene function.

Environmental Influences

External factors such as diet, stress, and exposure to chemicals that can impact gene expression and lead to phenotypic variations.

Somatic Mutations

Mutations that occur in somatic cells and are not passed on to offspring; can lead to cancers and other diseases in the individual.

Germline Mutations

Mutations that occur in germ cells and can be passed on to the next generation, potentially leading to inherited disorders.

Transcription

The process by which the genetic information encoded in DNA is copied to produce a complementary RNA strand.

Translation

The process of synthesizing proteins from mRNA templates, with the help of ribosomes and transfer RNA (tRNA).

Mutation Types

Different categories of mutations including point mutations, insertions, deletions, and frameshift mutations, each affecting protein function differently.

Phenotypic Variation

Differences in appearance or function among individuals of the same species, often caused by genetic and environmental factors.

Gene Regulation

The mechanisms and processes that control the expression of specific genes in response to environmental or developmental cues.

T cell Activation

The process by which T cells of the immune system recognize antigens and become activated to combat infections and tumors.

Antibody Production

The immune response where B cells produce antibodies specific to antigens, which are critical for fighting infections and diseases.

Viral Genomics

The study of the genetic material of viruses and how it interacts with the host genome, impacting both viral replication and host immune response.

Genetic Disorders

Common genetic diseases include Cystic Fibrosis, Huntington's Disease, Sickle Cell Anemia, and genetic cancers like BRCA-related breast cancer and Lynch syndrome.

Mendelian Inheritance

Inheritance patterns that follow Mendel's laws, including dominant and recessive traits where alleles segregate independently during gamete formation.

Non-Mendelian Inheritance

Inheritance patterns that do not follow Mendel's laws, including incomplete dominance (where the phenotype is a blend) and codominance (where both traits are expressed).

Chromosomal Structure

Made up of DNA and proteins, chromosomes consist of centromeres, telomeres, and gene loci, crucial for proper segregation during cell division.

Punnett Square

A tool used to predict the genotypes and phenotypes of offspring from genetic crosses by mapping possible allele combinations from parents.

Pedigree Analysis

A method for tracking the inheritance of genetic traits across generations in a family tree format, useful for assessing genetic diseases.

Karyotype

The number and appearance of chromosomes in an individual’s cells, helping identify chromosomal abnormalities such as aneuploidies.

DNA Sequencing

The process of determining the sequence of nucleotides in a DNA molecule, vital for understanding genetic mutations and variants.

RNA Structure

RNA is typically single-stranded and consists of ribose sugar, phosphate groups, and nitrogenous bases (adenine, uracil, cytosine, guanine).

Gene Therapy

A cutting-edge treatment strategy that modifies a person's genes to treat or prevent diseases by introducing, removing, or altering genetic material within a cell.

Protein Synthesis

The process through which cells construct proteins by transcribing DNA into messenger RNA (mRNA) and subsequently translating mRNA into amino acid sequences.

Meiosis

A specialized type of cell division that produces haploid gametes (sperm and eggs) from diploid cells, involving two rounds of division and genetic recombination.

Chromosome Mutations

Changes to the structure or number of chromosomes (e.g., deletions, duplications, inversions) that can lead to genetic disorders or cancer.

Gene Expression

The process by which information from a gene is used to synthesize a functional gene product, typically a protein, controlling the traits expressed in the organism.

Epigenetics

The study of heritable changes in gene expression that do not involve alterations to the underlying DNA sequence, influenced by environmental factors and lifestyle.

Mutations

Permanent alterations in the DNA sequence that can lead to different traits and potentially cause diseases; includes point mutations, insertions, and deletions.

Immune System Interaction

The immune response towards pathogens, where immune cells recognize and react to viruses, influencing genetic expression related to immunity and disease susceptibility.

Basic Chemical Principles

Fundamental concepts in chemistry essential to understanding molecular interactions, bonding, and reactions that underlie biological processes.