SHS Biology A Final Study Guide

Biotechnology

The use of living organisms cells

Codon

A sequence of three nucleotides in DNA or RNA that corresponds to a specific amino acid or stop signal during protein synthesis.

Connective Tissue

A type of tissue in the body that supports connects

Differentiation

The process by which unspecialized cells such as stem cells

Epithelial Tissue

A type of tissue that forms the outer layer of the body and lines internal organs and structures providing protection

Frameshift Mutation

A genetic mutation caused by the insertion or deletion of a nucleotide which shifts the reading frame of the genetic code and often results in nonfunctional proteins.

Gel Electrophoresis

A laboratory technique used to separate DNA RNA

Gene Expression

The process by which genetic information in DNA is transcribed into RNA and translated into proteins resulting in the manifestation of traits.

Gene Therapy

A medical technique that involves modifying or replacing defective genes to treat or prevent diseases.

Genetic Code

The set of rules by which the sequence of nucleotides in DNA or RNA is translated into amino acids which form proteins.

Homologous Chromosome

A pair of chromosomes one inherited from each parent

Messenger RNA (mRNA)

A type of RNA that carries the genetic information from DNA to the ribosome where it serves as a template for protein synthesis.

Muscle Tissue

A type of tissue composed of fibers that can contract producing movement or maintaining posture in the body. It includes skeletal

Mutation

A change in the DNA sequence that can alter gene function and may lead to variations or disorders.

Mutagen

An agent such as radiation or chemicals

Multipotent

Refers to stem cells that can differentiate into a limited range of cell types related to a specific tissue or organ.

Nervous Tissue

A type of tissue composed of neurons and supporting cells that transmits electrical signals and processes information in the nervous system.

Pluripotent

Refers to stem cells capable of differentiating into almost all cell types in the body except for extra embryonic tissues.

Point Mutation

A mutation affecting a single nucleotide in a DNA sequence which may result in a change to a protein.

Polypeptide

A chain of amino acids linked by peptide bonds that folds into a functional protein.

Protein

A biomolecule composed of one or more polypeptides responsible for various functions in the body

RNA Polymerase

An enzyme that synthesizes RNA from a DNA template during the process of transcription.

Recombinant DNA

DNA molecules formed by combining genetic material from different sources to create new genetic sequences.

Restriction Enzyme

An enzyme that cuts DNA at specific nucleotide sequences often used in genetic engineering and molecular cloning.

Ribosome

A molecular structure in cells where mRNA is translated into proteins by linking amino acids in the correct order.

Stem Cell

An unspecialized cell capable of self-renewal and differentiation into specialized cell types.

Transcription

The process by which a segment of DNA is copied into RNA by RNA polymerase.

Transfer RNA (tRNA)

A type of RNA that brings the appropriate amino acids to the ribosome during protein synthesis.

Translation

The process in which the sequence of a messenger RNA (mRNA) is decoded to produce a specific protein.

Totipotent

Refers to stem cells that can differentiate into all cell types including both embryonic and extra embryonic tissues

Allele

Different versions of a gene that determine a specific trait.

Autosome

Any chromosome that is not a sex chromosome.

Chromosomal Mutation

A change in the structure or number of chromosomes which can lead to genetic disorders.

Carrier

An individual who has one copy of a recessive allele but does not show the trait though they can pass it on.

Codominance

A type of inheritance where both alleles in a heterozygous individual are fully expressed (e.g. AB blood type).

Crossing-over

The exchange of genetic material between homologous chromosomes during meiosis increasing genetic diversity.

Diploid

A cell that contains two sets of chromosomes (one from each parent) written as 2n.

Dihybrid

A genetic cross that involves two traits such as seed shape and seed color in pea plants.

Fertilization

The fusion of a sperm and egg cell to form a zygote.

Gamete

A reproductive cell (sperm or egg) that carries half the genetic material of an organism.

Gene

A section of DNA that codes for a specific protein and determines traits.

Genetics

The study of heredity and how traits are passed from parents to offspring.

Genome

The complete set of genetic material in an organism.

Genotype

The genetic makeup of an organism represented by allele combinations (e.g.

Haploid

A cell that has only one set of chromosomes (half the usual number) written as n (e.g.

Heterozygous

Having two different alleles for a gene (e.g. Bb).

Homologous Chromosome

A pair of chromosomes (one from each parent) that have the same genes but may have different alleles.

Homozygous

Having two identical alleles for a gene (e.g. BB or bb).

Incomplete Dominance

A type of inheritance where the heterozygous phenotype is a blend of the two alleles (e.g. red and white flowers making pink flowers).

Karyotype

A picture of all the chromosomes in a cell used to identify chromosomal abnormalities.

Law of Dominance

Mendel’s principle that states that some alleles are dominant and will be expressed over recessive alleles.

Law of Independent Assortment

Mendel’s principle stating that genes for different traits are inherited independently of one another.

Law of Segregation

Mendel’s principle that states that allele pairs separate during gamete formation so that each gamete carries only one allele for each gene.

Meiosis

A type of cell division that reduces the chromosome number by half producing four genetically different haploid gametes.

Monohybrid

A genetic cross that involves only one trait.

Multiple Alleles

When a gene has more than two possible alleles (e.g. blood type: A

Nondisjunction

The failure of chromosomes to separate properly during meiosis leading to disorders like Down syndrome.

Pedigree

A chart used to track inheritance patterns of traits within a family.

Phenotype

The physical expression of a trait (e.g. blue eyes

Polygenic Traits

Traits controlled by multiple genes such as skin color or height.

Punnett Square

A diagram used to predict the possible genetic outcomes of a cross.

Sex Chromosome

Chromosomes that determine an organism’s sex (X and Y in humans).

Sex-linked Gene

A gene located on a sex chromosome often affecting traits like color blindness in males.

Somatic Cell

Any body cell that is not a gamete (e.g. skin cells

Trait

A characteristic determined by genes such as eye color or blood type.

Zygote

A fertilized egg cell the first cell of a new organism.

Adaptation

A trait or characteristic that helps an organism survive and reproduce in its environment.

Allele Frequency

How common a specific form of a gene (allele) is in a population. It’s usually shown as a percentage.

Analogous Structure

Body parts that have a similar function but different structures and evolutionary origins. For example wings of birds and wings of insects.

Clade

A group of organisms that share a common ancestor and all of its descendants.

Cladogram

A diagram that shows evolutionary relationships between different groups of organisms based on shared traits.

Directional Selection

A type of natural selection where one extreme version of a trait is favored causing the population to shift in that direction.

Disruptive Selection

A type of natural selection where extreme traits are favored over the average ones possibly leading to two distinct groups.

Derived Character

A trait that evolved in the most recent common ancestor of a clade and sets members of that clade apart from other groups.

Evolution

The process of change in species over time through natural selection and other mechanisms.

Fitness

An organism’s ability to survive and reproduce in its environment. High fitness means better chances of passing on genes.

Fossil

Preserved remains or traces of organisms that lived in the past often found in sedimentary rock.

Geographic Isolation

When populations of a species are separated by physical barriers like mountains or bodies of water preventing them from mating.

Gene Pool

All the genes including all the different alleles

Homologous Structure

Body parts that are similar in structure but may have different functions showing common ancestry. Example: human arm and whale flipper.

Natural Selection

The process where organisms better suited to their environment are more likely to survive and reproduce.

Phylogeny

The evolutionary history and relationships among species or groups of species.

Reproductive Isolation

When different groups of organisms can no longer mate successfully with each other leading to the formation of new species.

Selective Pressure

Factors in the environment that influence which traits are advantageous and therefore become more common.

Speciation

The formation of new species from an existing species due to evolutionary processes like natural selection and genetic isolation.

Species

A group of organisms that can interbreed and produce fertile offspring.

Stabilizing Selection

A type of natural selection where the average trait is favored and extremes are selected against keeping a population stable.

Vestigial Structure

Body parts that have lost their original function through evolution but are still present. Example: human appendix.

Autotroph

An organism that produces its own food using light water

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem. This includes diversity within species between species

Biogeochemical Cycle

The cycling of substances (such as water carbon

Bioaccumulation

The buildup of substances (like pesticides or heavy metals) in an organism over time typically because the organism absorbs the substance faster than it can be metabolized or excreted.

Biomass

The total mass of living organisms in a given area or volume. It's often measured in terms of dry weight.

Biosphere

The regions of the surface atmosphere

Biomagnification

The increasing concentration of a substance (like a toxin) in the tissues of organisms at successively higher levels in a food chain.

Carbon

A chemical element that is the main component of organic compounds and is essential for all known life on Earth. It cycles through the environment in the carbon cycle.

Carrying Capacity

The maximum population size of a species that an environment can sustain indefinitely given the available resources such as food water

Commensalism

A symbiotic relationship between two organisms of different species where one benefits and the other is neither harmed nor helped.

Community

An interacting group of various species in a common location. For example a forest community might include trees

Consumer

An organism that feeds on other organisms or organic matter. Consumers obtain energy by eating producers or other consumers. They are also called heterotrophs.