IB Biology Topic 3 Definitions

The destruction method involving sticking pathogens together to make phagocytosis easier

A disease characterized by a low white blood cell count caused by HIV

Various specific forms of a gene that only differ from each other by one or a few bases

A systemic reaction to a normally harmless substance, caused by basophil and mast cell oversecretion of histamine

A structural change in haemoglobin when oxygen binds to one of its haem groups, increasing the affinity of the other subunits for oxygen

The smallest component in the lungs where gas exchange occurs

A method of fetal cell sampling whereby a needle is inserted into the abdomen to remove amniotic fluid from the amniotic sac around the fetus

A stationary point during contraction

A pair of muscles that exert forces in opposite directions to one another

A chemical produced by microorganisms that kills or controls the growth of bacteria by blocking prokaryotic cell processes and not eukaryotic ones

Surface molecules expressed on any organism or virus

A connection between bones

Classification of species on the basis of visual observation

A process by which a substance is radioactively labelled, coated with photographic film, and then viewed under a microscope

The destruction method involving binding to bacteria and viruses to prevent them from binding to cells

The change in the oxygen dissociation curve due to variations in pH, carbon dioxide levels, and temperature, affecting haemoglobin's oxygen affinity

An individual that is heterozygous for a genetic disease

When a stream of water is broken in a xylem, which cannot be repaired and renders the xylem unusable

The part of the brain that coordinates balance and fine-tunes motor skills

The largest part of the brain, divided into two hemispheres and four lobes (temporal, frontal, occipital, and parietal), responsible for higher brain functions such as speech, planning, and memory

A method of fetal cell sampling whereby placental cells are taken with a needle

The daily rhythm of light from day and night

A group of organisms that has evolved from a common ancestor

The study of classifying clades

An inherited genotype of two dominant alleles that express a joint phenotype

The destruction method involving binding to pathogens to allow complement proteins to attack the pathogen by lysis

The division of characteristics into an infinite number of forms

The phenomenon where the binding of oxygen to one haemoglobin subunit increases the affinity of the other subunits for oxygen

A disease caused by the build-up of plaques that occlude the vessel and restrict blood flow, eventually leading to a heart attack

The occlusion of an artery by blood clots caused by the rupture of a plaque

Excessive loss of water that raises the internal solute concentration

Growth that occurs for a specific amount of time up to a determined point

A tool used for identifying organisms based on a series of choices that lead to the correct name of the given item

The division of characteristics into a finite number of different groups

Short sequences of conserved DNA that are specific and unique to each species, used for species identification

An allele who's phenotype is expressed over a recessive allele. Dominant alleles are capitalized (A)

A chronic and progressive disease characterized by a breakdown of alveolar walls leading to larger air sacs with thicker and less permeable walls

The study of incidence and causes of disease

The process of removing waste products from the body

The fusion of an egg and sperm outside the body, such as in fish and frogs

The fusion of pollen and an ovule to form a zygote

The fusion of an egg and sperm

An embryo that has developed skeletal tissue by 8 weeks

The uncoordinated contraction of cardiac muscle

Sex cell

The process of oxygen and carbon dioxide diffusing across the walls of the alveoli

The process by which leaves expel oxygen and obtain carbon dioxide

A heritable factor that consists of a length of DNA and influences a characteristic

All the genes in an organism

The alleles than an organism contains to exhibit a characteristic

The positive correlation between the number of differences between two species and the time since they diverged from a common ancestor

Deep folds on the surface of the cerebrum that increase its surface area

A plant that has adapted itself to a saline environment to conserve water

The passing of blood out of a vein into a semi-permeable dialysis membrane tube in dialysis fluid

The presence of two different alleles (Aa)

A infection that is notoriously difficult to treat beause it infects lymphocytes involved in antibody production and can destroy them over time, preventing antibody production

An organism's ability to maintain it's internal environment

The presence of two of the same alleles (AA or aa)

A cell that was formed from the fusion of a myeloma and memory cell

A novel method used to overcome fertility problems in males or females

A novel method used to overcome fertility problems in males or females

Growth that occurs indefinitely for an entire lifetime

A point that moves during contraction

The fusion of an egg and sperm inside the body, such as in humans

Non-native species that spread widely in a new habitat, often causing harm to the environment, economy, or human health

The disturbance of circadian rhythms due to travelling

An image showing an organism's homologous chromosome pairs in order of decreasing length to determine an individual's sex or or diagnose chromosomal abnormalities

A person's number and type of chromosomes

The surgical implantation of another individual’s donated kidney. Living donors can donate one kidney or dead donors one kidney to two people

A connective tissue that attaches bone to bone to keep them together and in place, only allowing movement in certain directions

Genes that are on the same chromosome

A specific position on a chromosome

The ability of memory cells to produce antibodies at a higher rate and quantity when an antigen is encountered again

A white blood cell involved in the non-specific immune response that ingests pathogens via phagocytosis and presents its antigen to a specific T-helper cell

A B cell clone that stays in the body after plasma cells have degraded and provide long term immunity

A 4-week repeating process of egg development and release for fertilization

A process by which plant stem cells are cultured in cytokinin and gibberella gel to grow an entirely new plant

Identical antibodies produced by hybridoma cells

The sliding of actin and myosin filaments over each other to pull the ends of each sarcomere together and shorten the entire muscle fiber

A large multinucleated cell that composes skeletal muscle

A substance capable of causing a mutation

A random change to the base sequence of a gene

A fatty insulating sheath around neurons in the peripheral nervous system (PNS) synthesized by Schwann cells, and in the central nervous system (CNS) by oligodendrocytes

A type of tumor cell

Long contractile fibers within a muscle cell

A protein in muscle tissue composed of one α chain with one haem group, having a higher affinity for oxygen and storing it for muscle respiration

Classification of species on the basis of genetic similarity

The process whereby substances decrease each other's levels

Supporting cells in the nervous system that provide structural and functional support to neurons

A nervous system cell that carries electrical impulses from the brain to the body or vice versa

The destruction method involving binding to toxins produced by pathogens to minimize their effect

Genes that are on different chromosomes

An immune response lead by phagocytes that consumes any pathogen that enters the body

The production of female gametes in the ovaries, commencing in puberty and lasting until the eggs are run out

The destruction method involving binding to pathogens and labelling them for phagocytes

An organism that does not control its own internal concentration and thus it is the same as the external solute concentration

An organism's control of its internal solute concentration

An organism that maintains a constant internal solute concentration, regardless of the external solute concentration

Excessive intake of water lowers the internal solute concentration

An organism or virus that causes a disease

A wave of muscle contraction that passes along the entire digestive tract

The endocytosis of pathogens by phagocytes

The characteristic physically exhibited by an organism

Plant vessels that transport organic compounds from sugar production sources to sugar storage sinks

A directional growth response to light

A B cell clone with a large rough endoplasmic reticulum to produce antibodies against the presented antigen

Small cell fragments that circulate in the blood and involved in clotting

The supplying of pollen to other plants to facilitate fertilization

The inheritance of multiple genes coding for a single characteristic

The fertilization of an egg by more than one sperm, which increase chromosome number, usually resulting in cell death or birth to sterile offspring

The process whereby substances increase each other's levels

A directional growth response to light towards the source of light

Growth of a plant in length

The sense of the relative position of body parts and strength of effort employed in movement, detected by receptors in muscles and joints

The circulation that carries unoxygenated blood through the lungs to be oxygenated and sent back to the heart

An allele who's phenotype is masked by a dominant allele. Recessive alleles are lowercase (a)

A new combination of linked genes made via recombinatinon during crossing over in prophase I

The plasma membrane of a muscle fiber

The smallest contractile unit of a myofibril

A network of tubules in muscle fibers that stores calcium ions and coordinates muscle contraction

Growth of a plant in width

The release of seeds so they can germinate and grow into more plants, often assisted by animals eating and defecating seeds or wind carrying the seeds to spread out the plants

The phenomenon of offspring inheriting one allele from each parent due to the formation of haploid nuclei during meiosis

A condition dependent on the sex of the individual because the allele is present on the X chromosome

Muscle attached to bone

A group of organisms that can potentially interbreed

An immune response lead by lymphocytes that produces antibodies to specific pathogens that enters the body

The production of male gametes in the testes, commencing during puberty and lasting indefinitely

Deep grooves in the cerebrum that divide the hemispheres into lobes

The process of increased follicular development

A moving connection between bones, but it only allows movement in certain directions

The circulation that supplies oxygenated blood to the body and brings unoxygenated blood back to the heart

The scientist that studies species classification

A connective tissue that attaches muscle to bone

The volume of air inhaled or exhaled

The loss of water as an inevitable consequence of gas exchange

The flow of water caused by evaporation at the leaf putting tension on the column of water

A growth response to an environmental factor

The consistent removal and replacement of air in the lungs via inhalation and exhalation of air

The number of inhalations or exhalations per minute

A plant that has adapted itself to a desert environment to conserve water

Plant vessels that transport water to replace the losses of transpiration