since i’m a biology student i had an idea that i’ll tweet luke a biology word + definition everyday until he follows me ! lmao sjdhs this means i get to study + luke might see this thread, learn new words and follow me hehe

day one – @Luke5SOS ‘autosome’ this is any chromosome other than a sex chromosome

day two – @Luke5SOS ‘erythrocyte’ is a type of cell in vertebrate blood, it has a small/disc shape and lacks most internal organelles. it contains large amounts of haemoglobin which is a protein that transports oxygen and also gives the cells its red colour !

day three – @Luke5SOS ‘cytoskeleton’ this is a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence

day four – @Luke5SOS ‘karyotype’ this is the appearance of the chromosomal makeup of a somatic cell in an individual or species (including the number, arrangement, size and structure of the chromosomes)

day five – @Luke5SOS ‘nucleotide’ this is the basic structural unit and building block for DNA! they’re composed of 3 parts:

* five-sided sugar
* phosphate group
* nitrogenous base

day six – @Luke5SOS ‘mutation’ this is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors. mutations are the raw material of genetic variation therefore are essential to evolution !

day seven – @Luke5SOS ‘gamete’ this is the male or female reproductive cell that contains half the genetic material of the organism

day eight - @Luke5SOS ‘zygote’ this is the cell formed by the union of a male sex cell (a sperm) and a female sex cell (an ovum). the zygote develops into the embryo following the instruction encoded in its genetic material

day nine - @Luke5SOS ‘allele’ this is each of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

day ten - @Luke5SOS ‘homeostasis’ this is the ability or tendency to maintain internal stability in an organism to compensate for environmental changes !

day eleven – @Luke5SOS ‘antigen’ this is a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies

day twelve – @Luke5SOS ‘myosin’ is a fibrous protein which forms (together with actin) the contractile filaments of muscle cells and is also involved in motion in other types of cell.

day thirteen – @Luke5SOS ‘genome’ this is the entire set of genetic material contained within the chromosomes of an organism, organelle or virus!

day fourteen – @Luke5SOS ‘adenosine triphosphate (ATP)’ is an energy-carrying molecule found in the cells of all living things. ATP captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processes !

day fifteen – @Luke5SOS ‘genotype’ this is the part of the genetic makeup of a cell, and therefore of any individual, which determines one of its characteristics

day sixteen – @Luke5SOS ‘phenotype’ this is the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment

day seventeen – @Luke5SOS ‘eukaryote’ this is an organism whose cells contain a nucleus within a membrane. the genetic material and information of a eukaryote is contained within this nucleus.

day eighteen – @Luke5SOS ‘carrier proteins’ carry substances from one side of a biological membrane to the other. many carrier proteins are found in a cell’s membrane, as well as in the membranes of internal organelles. two types are channel proteins and transport proteins!

day nineteen – @Luke5SOS ‘coenzyme’ this is an organic non-protein compound that binds with an enzyme to catalyze a reaction. a coenzyme cannot function alone, but can be reused several times when paired with an enzyme!

day twenty – @Luke5SOS ‘denaturing’ is when a biological molecule loses its three-dimensional (3d) structure. since molecules like proteins and DNA depend on their structure to accomplish their function, denaturation is accompanied by a loss of function.

day twenty-one – @Luke5SOS ‘somatic cells’ these are any cell in the body that are not gametes (sperm or egg), germ cells (cells that go on to become gametes), or stem cells.

day twenty-two – @Luke5SOS ‘ligand’ this is any molecule or atom which binds reversibly to a protein. a ligand can be an individual atom or ion. it can also be a larger and more complex molecule made from many atoms

day twenty-three – @Luke5SOS ‘pedigree’ this is a diagram that depicts the biological relationships between an organism and its ancestors !!

day twenty-four – @Luke5SOS ‘symbiosis’ this is an interaction between two different organisms living in close physical association, typically to the advantage of both.

day twenty-five – @Luke5SOS ‘tissues’ these are groups of cells that have a similar structure and act together to perform a specific function. there are four different types of tissues in animals:

* connective
* muscle
* nervous
* epithelial

day twenty-six – @Luke5SOS ‘gland’ this is a group of cells or a “secreting organ” that excretes a chemical substance. this substance can take the form of hormones, sweat, saliva, mucus, or acids (i.e. HCl acid in gastric glands).

day twenty-seven – @Luke5SOS ‘trachea’ is the pipe serving as the principal passage for movement of air to and from the lungs, in humans and other vertebrates. it extends from the larynx to the bronchus !!

day twenty-eight – @Luke5SOS ‘plasmid’ is a small, circular piece of DNA that is different than the chromosomal DNA. plasmids are mainly found in bacteria, but they can also be found in archaea and multicellular organisms !

day twenty-nine – @Luke5SOS ‘apoptosis’ this is a process that occurs in multicellular when a cell intentionally “decides” to die. this often occurs for the greater good of the whole organism, such as when the cell’s DNA has become damaged and it may become cancerous.

day thirty – @Luke5SOS ‘active site’ an enzymes active site is the site at which the enzyme binds to the substrates and increases their chances of reacting. enzymes are proteins which drastically increase the speed of chemical reactions by lowering their activation energy !

day thirty-one – @Luke5SOS ‘white blood cell’ this is a type of blood cell that is made in the bone marrow and found in the blood and lymph tissue. they are part of the body’s immune system and help the body fight infection and other diseases !

day thirty-two – @Luke5SOS ‘gluconeogenesis’ this is the metabolic process by which organisms produce sugars (namely glucose) for catabolic reactions from non-carbohydrate precursors (examples are lactate and amino acids)

day thirty-three – @Luke5SOS ‘pathogen’ this is a bacterium, virus, or other microorganism that can cause disease

day thirty-four – @Luke5SOS ‘ectotherm’ this is an organism which derives the heat it requires from the environment. an ectotherm can regulate its temperature behaviorally, by moving into warmer areas or positioning themselves to reduce heat loss.

day thirty-five – @Luke5SOS ‘endotherm’ are organisms use internally generated heat to maintain body temperature. their body temperature tends to stay steady regardless of environment.

day thirty-six – @Luke5SOS ‘vesicles’ are compartments formed by a lipid bilayer separating its contents from the cytoplasm or a fluid-based extracellular environment. they can contain either liquids or gases and have a wide range of functions in cells

day thirty-seven – @Luke5SOS ‘stamen’ is the male reproductive organ of flowering plant species that produces pollen. the stamen is comprised of an anther, which is connected to a filament

day thirty-eight – @Luke5SOS ‘natural selection’ this is a process by which species of animals and plants that are best adapted to their environment survive and reproduce, while those that are less well adapted die out.

day thirty-nine – @Luke5SOS ‘xylem’ is a type of tissue in vascular plants that transports water and some nutrients from the roots to the leaves. the main function of xylem is to transport water, and some soluble nutrients including upwards from the roots to the rest of the plant

day forty – @Luke5SOS ‘phloem’ is the complex tissue, which acts as a transport system for soluble organic compounds within vascular plants. the phloem moves photoassimilates, mainly in the form of sucroseand proteins, from the leaves to the rest of the plant.

day forty-one – @Luke5SOS ‘soma’ this is the parts of an organism other than the reproductive cells.

day forty-two – @Luke5SOS ‘centromere’ this is a specialized condensed region of each chromosome that appears during mitosis where the chromatids are held together to form an X shape

day forty-three – @Luke5SOS ‘aerobic’ occurring in the presence of oxygen or requiring oxygen to live. in aerobic respiration, which is the process used by the cells of most organisms, the production of energy from glucose metabolism requires the presence of oxygen.

day forty-four – @Luke5SOS ‘wild type (WT)’ this refers to the phenotype of the typical form of a species as it occurs in nature.

day forty-five – @Luke5SOS ‘hormone’ this is a chemical substance produced in the body that controls and regulates the activity of certain cells or organs. many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland !

day forty-six – @Luke5SOS ‘ovule’ this is part of the makeup of the female reproductive organ in seed plants. it’s the place where female reproductive cells are made and contained, and it develops into a seed after fertilization, the seed then ripens and produces an adult plant.

day forty-seven – @Luke5SOS ‘artery’ this is any of the muscular-walled tubes forming part of the circulation system by which blood (mainly that which has been oxygenated) is conveyed from the heart to all parts of the body.

day forty-eight – @Luke5SOS ‘recessive gene’ this is a gene that can be masked by a dominant gene. a recessive allele has to team up with another recessive allele in order to for them phenotype to show up!

day forty-nine – @Luke5SOS ‘vein’ a blood vessel that carries blood that is low in oxygen content from the body back to the heart. veins are part of the afferent wing of the circulatory system, which returns blood to the heart.

day fifty – @Luke5SOS ‘codon’ this is a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis

day fifty-one – @Luke5SOS ‘single-nucleotide polymorphism (SNP) is a substitution of a single nucleotide that occurs at a specific position in the genome, where each variation is present at a level of more than 1% in the population

day fifty-two – @Luke5SOS ‘haplotype’ this is a group of alleles in an organism that are inherited together from a single parent

day fifty-three – @Luke5SOS ‘niche’ this is the match of a species to a specific environmental condition. it describes how an organism or population responds to the distribution of resources and competitors and how it in turn alters those same factors

day fifty-four – @Luke5SOS ‘ecosystem services’ grouped into 4 categories: provisioning, eg production of food/water; regulating, eg the control of climate/disease; supporting, eg nutrient cycles & oxygen production; and cultural, eg spiritual & recreational benefits

day fifty-five – @Luke5SOS ‘parasitism’ is a relationship between species, where one organism, the parasite, lives on or in another organism, the host, causing it some harm, and is adapted structurally to this way of life

day fifty-six – @Luke5SOS ‘hibernation’ this is the condition or period of an animal or plant spending the winter in a dormant state.

day fifty-seven – @Luke5SOS ‘autotroph’ an organism that produces complex organic compounds from simple substances present in its surroundings, generally using energy from light or inorganic chemical reactions. they are the producers in a food chain

day fifty-eight – @Luke5SOS ‘keystone species’ every ecosystem has certain species are critical to the survival of the other species in the system. the keystone species could be a huge predator or an unassuming plant, but without them the ecosystem may not survive.

day fifty-nine – @Luke5SOS ‘anabolism’ this is the synthesis in living organisms of more complex substances (e.g., living tissue) from simpler ones together with the storage of energy

day sixty – @Luke5SOS ‘catabolism’ this is the breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism

day sixty-one – @Luke5SOS ‘epiglottis’ is a leaf-shaped flap in the throat that prevents food from entering the windpipe and the lungs. it stands open during breathing, allowing air into the larynx.

day sixty-two – @Luke5SOS ‘transcription factor’ this is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence.

day sixty-three – @Luke5SOS ‘rod cell’ this is one of two kinds of photoreceptors in the vertebrate retina; sensitive to black and white and enables night vision.

day sixty-four – @Luke5SOS ‘cone cells’ are photoreceptor cells in the retinas of vertebrate eyes. they respond differently to light of different wavelengths, and are thus responsible for color vision and function best in relatively bright light

day sixty-five – @Luke5SOS ‘invasive species’ this is a species that is not native to a specific location (an introduced species), and that has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health.

say sixty-six – @Luke5SOS ‘a clone’ is an identical genetic copy of either a piece of deoxyribonucleic acid (DNA), a cell, or a whole organism. identical twins are clones, as are two daughter cells produced by mitosis .

day sixty-seven – @Luke5SOS ‘asexual reproduction’ this occurs when an organism makes more of itself without exchanging genetic information with another organism through sex.

day sixty-eight – @Luke5SOS ‘carotenoids’ are a type of accessory pigment, created by plants to help them absorb light energy and convert it to chemical energy. there are two types of carotenoids, xanthophylls and carotenes, which differ only in their oxygen content

day sixty-nine – @Luke5SOS ‘arthropod’ this is an invertebrate animal having an exoskeleton, a segmented body, and paired jointed appendages. arthropods form the phylum euarthropoda, which includes insects, arachnids, myriapods, and crustaceans

day seventy – @Luke5SOS ‘cellulose’ this is an insoluble substance which is the main constituent of plant cell walls and of vegetable fibres such as cotton. it is a polysaccharide consisting of chains of glucose monomers

day seventy-one – @Luke5SOS ‘active immunity’ this is usually long-lasting immunity that is acquired through production of antibodies within the organism in response to the presence of antigens

day seventy-two — @Luke5SOS ‘enantiomers’ these are each of a pair of molecules that are mirror images of each other

day seventy-three – @Luke5SOS ‘cerebellum’ this is the part of the brain at the back of the skull in vertebrates, which coordinates and regulates muscular activity.

day seventy-four – @Luke5SOS ‘cerebrum’ the most anterior part of the brain in vertebrates, located in the front area of the skull. it is responsible for the integration of complex sensory and neural functions and the initiation and coordination of voluntary activity in the body.

day seventy-five – @Luke5SOS ‘the hardy–weinberg principle’ states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences

day seventy-six – @Luke5SOS ‘gene pool’ the collection of different genes within an interbreeding population. the concept usually refers to the sum of all the alleles at all of the loci within the genes of a population of a single species. includes genes that are expressed/not

day seventy-seven – @Luke5SOS ‘true breeding’ organisms that can transit certain traits to all their offspring. appear to be similar to each other in appearance are homogenous for many characteristics that differentiate them from other members of the same species.

day seventy-eight – @Luke5SOS ‘genetic drift’ this is when alleles change frequency within a population due to random sampling. as a result, it does not produce adaptations

day seventy-nine – @Luke5SOS ‘gene flow’ this differs from genetic drift because it is the transfer of alleles or gametes from one population to another. it happens when a population migrates or becomes geographically isolated.

day eighty – @Luke5SOS ‘bottleneck effect’ occurs when a population's size is reduced for at least one generation. genetic drift acts more quickly to reduce genetic variation in small populations, undergoing a bottleneck can reduce a population's genetic variation by a lot

day eighty-one – @Luke5SOS ‘blood vessel’ a tubular structure carrying blood through the tissues and organs; a vein, artery, or capillary.

day eighty-two – @Luke5SOS ‘aestivation’ this is a prolonged torpor or dormancy of an insect, fish, or amphibian during a hot or dry period.

day eighty-three – @Luke5SOS ‘evolution’ the process by which different kinds of living organism are believed to have developed from earlier forms during the history of the earth.

day eighty-four – @Luke5SOS ‘torpor’ this is a state of decreased physiological activity or suspended animation in hibernating animals, characterised by reduced body temperature and metabolic rate.

day eighty-five – @Luke5SOS ‘the alimentary canal’ is a continuous passage starting from the mouth and ending at the anus, which carries food through different parts of the digestive system and allows waste to exit the body.

day eighty-six – @Luke5SOS ‘the central nervous system (CNS)’ consists of the brain and spinal cord. this body system is responsible for integrating and coordinating the activities of the entire body

day eighty-seven – @Luke5SOS ‘hydrophobic’ literally means “the fear of water”. hydrophobic molecules and surfaces repel water. they are usually non-polar, meaning the atoms that make the molecule do not produce a static electric field.

say eighty-eight – @Luke5SOS ‘hydrophilic’ these molecules are attracted to water. water is a polar molecule dissolves other polar and hydrophilic substances. in biology, many substances are hydrophilic, which allows them to be dispersed throughout a cell or organism.

day eighty-nine – @Luke5SOS ‘phospholipid bilayer’ a thin polar membrane made of two layers of lipid molecules. phospholipids with certain head groups can alter the surface chemistry of a bilayer and can, for example, serve as signals as well as "anchors" for other molecules

day ninety – @Luke5SOS ‘neuron’ a specialised cell transmitting nerve impulses; a nerve cell

day ninety-one – @Luke5SOS ‘glial cells’ surround neurons and provide support for and insulation between them. types of glial cells include oligodendrocytes, astrocytes, ependymal cells, schwann cells, microglia, and satellite cells.

day ninety-two – @Luke5SOS ‘muscle tissue’ is a soft tissue that composes muscles in animal bodies, and gives rise to muscles' ability to contract. this is opposed to other components or tissues in muscle such as tendons or perimysium.

day ninety-three – @Luke5SOS ‘microtubule’ a microscopic tubular structure present in numbers in the cytoplasm of cells, sometimes aggregating to form more complex structures.

day ninety-four – @Luke5SOS ‘medulla oblongata’ helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing. it is a center for respiration and circulation. sensory and motor neurons from the forebrain and midbrain travel through the medulla

day ninety-five – @Luke5SOS ‘microglial cells’ are a specialised population of macrophages that are found in the central nervous system (CNS). they remove damaged neurons and infections and are important for maintaining the health of the CNS.

day ninety-six – @Luke5SOS ‘action potential’ the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell.

day ninety-seven – @Luke5SOS ‘hypothalamus’ a small region of the brain. located at the base of the brain, near the pituitary gland. while it's very small, the hypothalamus plays a crucial role in many important functions: releasing hormones. regulating body temperature

say ninety-eight – @Luke5SOS ‘thyroid’ a large ductless gland in the neck which secretes hormones regulating growth and development through the rate of metabolism.

day ninety-nine – @Luke5SOS ‘sarcomere’ a structural unit of a myofibril in striated muscle, consisting of a dark band and the nearer half of each adjacent pale band.

day one-hundred – @Luke5SOS ‘titin’ also known as connectin, is a protein that is encoded by the TTN gene in humans. functions as a molecular spring which is responsible for the passive elasticity of muscle in addition to keeping myosin molecules in place

day one-hundred and one – @Luke5SOS ‘ganglion’ a cluster of neural bodies outside the central nervous system. a spinal ganglion, for instance, is a cluster of nerve bodies positioned along the spinal cord at the dorsal and ventral roots of a spinal nerve.

day one-hundred and two – @Luke5SOS ‘endocytosis’ is the process of actively transporting molecules into the cell by engulfing it with its membrane. endocytosis and exocytosis are used by all cells to transport molecules that cannot pass through the membrane passively.

day one-hundred and three – @Luke5SOS ‘abiogenesis’ is the creation of organic molecules by forces other than living organisms. While organisms can create carbon-carbon bonds relatively easily thanks to enzymes, to do so otherwise requires large inputs of energy.

day one-hundred and four – @Luke5SOS ‘goblet cells’ are a major secretory cellular lineage in the intestinal epithelium that produce mucus, which is composed chiefly of mucins and inorganic salts suspended in water

day one-hundred and five – @Luke5SOS ‘thrombocytes’ are pieces of very large cells in the bone marrow called megakaryocytes. they help form blood clots to slow or stop bleeding and to help wounds heal.

day one-hundred and six – @Luke5SOS ‘vena cava’ a large vein carrying deoxygenated blood into the heart. there are two in humans, the inferior vena cava (carrying blood from the lower body) and the superior vena cava (carrying blood from the head, arms, and upper body).

day one-hundred and seven – @Luke5SOS ‘satellite cells’ are small multipotent cells with very little cytoplasm found in mature muscle. satellite cells are precursors to skeletal muscle cells, able to give rise to satellite cells or differentiated skeletal muscle cells.

day one-hundred and eight – @Luke5SOS ‘stable cells’ are cells that multiply only when needed. they spend most of the time in the G₀ phase of the cell cycle, but can be stimulated to enter the cell cycle when needed. examples include: the liver and endocrine glands

day one-hundred and nine (ignore that i missed 2 days oops) – @Luke5SOS ‘induced pluripotent stem cells’ adult cells that have been genetically reprogrammed to an embryonic stem cell–like state by being forced to express genes and factors

day one-hundred and ten – @Luke5SOS ‘myocardial infarction’ also known as a heart attack, occurs when blood flow decreases or stops to a part of the heart, causing damage to the heart muscle.

day one-hundred and eleven – @Luke5SOS ‘taxonomy’ is the science of naming, defining (circumscribing) and classifying groups of biological organisms on the basis of shared characteristics.

day one-hundred and twelve – @Luke5SOS ‘sexual dimorphism’ is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs. the condition occurs in many animals and some plants.

day one-hundred and thirteen – @Luke5SOS ‘teratoma’ is a rare type of tumor that can contain fully developed tissues and organs, including hair, teeth, muscle, and bone. teratomas are most common in the tailbone, ovaries, and testicles, but can occur elsewhere in the body.

day one-hundred and fourteen – @Luke5SOS ‘mast cell’ a cell filled with basophil granules, found in numbers in connective tissue and releasing histamine and other substances during inflammatory and allergic reactions.

day one-hundred and sixteen – @Luke5SOS ‘femur’, also called thighbone, upper bone of the leg. head forms a ball-and-socket joint with the hip (at the acetabulum), being held in place by a ligament (ligamentum teres femoris) within the socket and by strong surrounding ligaments

day one-hundred and seventeen – @Luke5SOS ‘islet cells’ clusters of cells that produce hormones in the pancreas. there are several different types of cells in an islet. for example, alpha cells make the hormone glucagon, which raises the glucose level in the blood.

day one-hundred and eighteen – @Luke5SOS ‘zoonotic diseases’ is an infectious disease caused by bacteria, viruses and parasites that spread from non-human animals (usually vertebrates) to humans. major modern diseases such as ebola virus disease and salmonellosis are zoonoses

day one-hundred and nineteen – @Luke5SOS ‘fundamental niche’ is the entire set of conditions under which an animal (population, species) can survive and reproduce itself.

day one-hundred and twenty – @Luke5SOS ‘realised niche’ is the set of conditions actually used by given animal (pop, species), after interactions with other species (predation and especially competition) have been taken into account.

day one-hundred and twenty-one – @Luke5SOS ‘tubulin’ a protein that is the main constituent of the microtubules of living cells.

day one-hundred and twenty-two – @Luke5SOS ‘negative control’ is part of a well-designed scientific experiment. the negative control group is a group in which no response is expected.

day one-hundred and twenty-three – @Luke5SOS ‘intercostal muscles’ several groups of muscles that run between the ribs, and help form chest wall. mainly involved in the mechanical aspect of breathing and help expand and shrink the size of the chest cavity to facilitate breathing.

day one-hundred and twenty-four – @Luke5SOS ‘central chemoreceptors’ (medullary neurons) primarily function to regulate respiratory activity. this is an important mechanism for maintaining arterial blood pO2, pCO2, and pH within appropriate physiological ranges.

day 125 – @Luke5SOS ‘microsatellite’ a tract of repetitive DNA in which certain motifs are repeated, typically 5–50 times. occur at thousands of locations within a genome and have a higher mutation rate than other areas of DNA, leads to high genetic diversity

day 126 - @Luke5SOS ‘VO2 max’ the maximum or optimum rate at which the heart, lungs, and muscles can effectively use oxygen during exercise, used as a way of measuring a person's individual aerobic capacity.

day 127 – @Luke5SOS ‘genetic diversity’ the total number of genetic characteristics in the genetic makeup of a species. genetic diversity serves as a way for populations to adapt to changing environments.

day 128 – @Luke5SOS ‘karyotype’ is simply a picture of a person's chromosomes. in order to get this picture, the chromosomes are isolated, stained, and examined under the microscope. most often, this is done using the chromosomes in the white blood cells.

day 129 – @Luke5SOS ‘cartilage’ firm, flexible connective tissue found in various forms in the larynx and respiratory tract, in structures such as the external ear, and in the articulating surfaces of joints.

day 130 lmao – @Luke5SOS ‘myelin’ is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. it is made up of protein and fatty substances and allows electrical impulses to transmit quickly and efficiently along the nerve cells.

day 131 – @Luke5SOS ‘pulmonary artery’ carries deoxygenated blood from the right ventricle to the lungs. the blood here passes through capillaries adjacent to alveoli and becomes oxygenated as part of the process of respiration.

day 132 – @Luke5SOS ‘vena cava’ a large vein carrying deoxygenated blood into the heart. there are two in humans, the inferior vena cava (carrying blood from the lower body) and the superior vena cava (carrying blood from the head, arms, and upper body).

133 – @Luke5SOS ‘ligand’ a substance that forms a complex with a biomolecule to serve a biological purpose. in protein-ligand binding, the ligand is usually a molecule which produces a signal by binding to a site on a target protein.

134 – @Luke5SOS ‘metabolism’ this is the chemical processes that occur within a living organism in order to maintain life.

135 – @Luke5SOS ‘pseudopod’ is a temporary arm-like projection of a eukaryotic cell membrane that are developed in the direction of movement. filled with cytoplasm, pseudopodia primarily consist of actin filaments and may also contain microtubules and intermediate filaments.

day 136 – @Luke5SOS ‘amoeba’ is a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods. amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms

day 137 – @Luke5SOS ‘helper T cells’ a type of T cell that provides help to other cells in the immune response by recognizing foreign antigens and secreting substances called cytokines that activate T and B cells

day 138 – @Luke5SOS ‘frontal lobe’ each of the paired lobes of the brain lying immediately behind the forehead, including areas concerned with behaviour, learning, personality, and voluntary movement.

day 139 – @Luke5SOS ‘the brainstem’ is the lowest part of the brain that merges with the spinal cord; it consists of a structure called the medulla oblongata, the midbrain and the pons.

day 140 – @Luke5SOS ‘arbor vitae‘ is a part of the brain. it is the cerebellar white matter, so called for its branched, tree-like appearance. it brings sensory and motor information to and from the cerebellum and is located deep in the cerebellum.

day 141 – @Luke5SOS ‘the central sulcus’ is a prominent landmark of the brain, separating the parietal lobe from the frontal lobe and the primary motor cortex from the primary somatosensory cortex.

day 142 – @Luke5SOS (PLEASE LOOK) ‘tendon’ a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.
the hamstring of a quadruped.

day 143 – @Luke5SOS ‘cell junctions’ (or intercellular bridges) are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals.

day 144 – @Luke5SOS ‘thyroid’ a large ductless gland in the neck which secretes hormones regulating growth and development through the rate of metabolism.

day 145 – @Luke5SOS ‘antibody’ a blood protein produced in response to and counteracting a specific antigen. antibodies combine chemically with substances which the body recognizes as alien, such as bacteria, viruses, and foreign substances in the blood.

day 146 – @Luke5SOS ‘blood clot’ a gelatinous mass of fibrin and blood cells formed by the coagulation of blood.

day 147 – ‘antigen’ a substance capable of stimulating an immune response or reaction.

day 148 – @Luke5SOS ‘lymphocyte’ a type of white bloodcell, varieties of which include B cells and Tcells, or B lymphocytes and T lymphocytes.

day 149 – @Luke5SOS ‘phagocyte’ a cell that engulfs and digests another cell

day 150 – @Luke5SOS ‘immune system’ is a network of organs, glands, and tissues that protects the body from foreign substances.

day 151 – @Luke5SOS ‘adrenal glands’ located on top of each kidney, these two glands are involved in the body’s response to stress and help regulate growth, blood glucose levels, and the body’s metabolic rate. receive signals from the brain and secrete several different hormones.

day 152 (of tryna get lukes follow lol) – @Luke5SOS ‘metamorphosis’ is a process that some animals go through in which they change from an immature form to an adult form.

day 153 – @Luke5SOS ‘coevolution’ refers to the evolution of at least two species, which occurs in a mutually dependent manner. it functions by reciprocal selective pressures on two or more species, analogous to an arms race in an attempt to outcompete each other.

day 154 – @Luke5SOS ‘blood-brain barrier’ a diffusion barrier between the brain vasculature and the substance of the brain formed by tight junctions between capillary endothelial cells.

day 155 – @Luke5SOS ‘larva’ the active immature form of an insect, especially one that differs greatly from the adult and forms the stage between egg and pupa, e.g. a caterpillar or grub.

day 156 – @Luke5SOS ‘sulcus’ is a shallower groove on the brain’s cerebrum (deeper grooves are called fissures).

day 157 – @Luke5SOS ‘axon terminal’ the very end of the axon, where electrochemical signals are passed through the synapse to neighboring cells by means of neurotransmitters and other neurochemicals.

day 158 – @Luke5SOS ‘capsid’ is the protein shell of a virus. it consists of several oligomeric structural subunits made of protein called protomers. the capsid encloses the genetic material of the virus.

day 159 – ‘caspases’ are a family of protease enzymes playing essential roles in programmed cell death and inflammation. they are named caspases due to their specific cysteine protease activity – a cysteine in its active site nucleophilically attacks and cleaves a target protein

day 160 – ‘metatarsals’ part of the bones of the mid-foot and are tubular in shape. they are named by numbers and start from the medial side outward. the medial side is the same side as the big toe.

dsy 161 — @Luke5SOS ‘oropharynx’ the part of the throat at the back of the mouth behind the oral cavity. it includes the back third of the tongue, the soft palate, the side and back walls of the throat, and the tonsils.

day 162 – @Luke5SOS ‘hematopoiesis’ is the term used to describe the differentiation of blood cells from hematopoietic stem cells. this process is continually required to maintain the levels of circulating blood cells in the body.

day 163 — @Luke5SOS ‘mast cell’ a cell filled with basophil granules, found in numbers in connective tissue and releasing histamine and other substances during inflammatory and allergic reactions

day 164 — @Luke5SOS ‘neuropathy’ disease or dysfunction of one or more peripheral nerves, typically causing numbness or weakness.

day 165 — @Luke5SOS ‘amygdala’ part of the brain’s limbic system, this primitive brain structure lies deep in the center of the brain and is involved in emotional reactions, such as anger or fear, as well as emotionally charged memories.

day 166 – @Luke5SOS ‘cerebellar tonsil’ is analogous to a rounded lobule on the undersurface of each cerebellar hemisphere, continuous medially with the uvula of the cerebellar vermis and superiorly by the flocculonodular lobe.

day 167 – @Luke5SOS ‘hyperarousal, or the acute stress response)’ is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival! commonly known as flight or fight response

day 168 – @Luke5SOS ‘immunity’ the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells.

day 169 – @Luke5SOS ‘primer’ a primer is a short single-stranded nucleic acid utilized by all living organisms in the initiation of DNA synthesis.

day 170 – @Luke5SOS ‘dermis’ the thick layer of living tissue below the epidermis which forms the true skin, containing blood capillaries, nerve endings, sweat glands, hair follicles, and other structures.

day 171 – @Luke5SOS ‘duct’ a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance eg “the tear duct was obstructed"

day 172 – @Luke5SOS ‘fibula’ the outer and usually smaller of the two bones between the knee and the ankle (or the equivalent joints in other terrestrial vertebrates), parallel with the tibia.

day 173 – @Luke5SOS ‘femur’ the bone of the thigh or upper hindlimb, articulating at the hip and the knee.

day 174 – @Luke5SOS ‘cerebrospinal fluid’ a clear, colorless body fluid found in the brain and spinal cord. it is produced by specialised ependymal cells in the choroid plexuses of the ventricles of the brain, and absorbed in the arachnoid granulations!

day 175 – @Luke5SOS ‘cytokine(s)’ any of a number of substances, such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system and have an effect on other cells.

day 176 – @Luke5SOS ‘keratin’ a hard insoluble protein substance found in hair, nails of mammals, scales of reptiles and bird feathers. this substance is responsible for the structure of hair, nails, scales, etc.

day 177 – @Luke5SOS ‘platelet’ a small colourless disc-shaped cell fragment without a nucleus, found in large numbers in blood and involved in clotting.

day 178 – ‘natural killer cells (nk cells)’ are a type of lymphocyte (a white blood cell) and a component of innate immune system. nk cells play a major role in the host-rejection of both tumours and virally infected cells.

day 179 – @Luke5SOS ‘immunoglobulin’ any of a class of proteins present in the serum and cells of the immune system, which function as antibodies

day 180 – @Luke5SOS ‘clavicle’ a bone of the shoulder girdle typically serving to link the scapula and sternum (also called collarbone)

day 181 – @Luke5SOS ‘ligament’ a short band of tough, flexible fibrous connective tissue which connects two bones or cartilages or holds together a joint.

day 182 – @Luke5SOS ‘hepatocytes’ are cells of the liver that carry out many metabolic functions, including the production of bile.

day 183 – @Luke5SOS ‘melatonin’ a hormone secreted by the pineal gland which inhibits melanin formation and is thought to be concerned with regulating the reproductive cycle.

day 184 – @Luke5SOS ‘the ulna gives structure to the forearm. the ulna is located on the opposite side of the forearm from the thumb. it joins with the humerus on its larger end to make the elbow joint, and joins with the carpal bones of the hand at its smaller end’

day 185 – @Luke5SOS ‘the talus bone ‘or ‘ankle bone’ is one of the group of foot bones known as the tarsus. the tarsus forms the lower part of the ankle joint. it transmits the entire weight of the body from the lower legs to the foot.

day 186 – @Luke5SOS ‘cilia’ found in the lungs, respiratory tract and middle ear. these cilia have a rhythmic waving or beating motion. they work, for instance, to keep the airways clear of mucus and dirt, allowing us to breathe easily and without irritation.

day 197 – @Luke5SOS ‘primary producer’ green plants, algae and some bacteria called the cyanobacteria which produce their own food by a process called photosynthesis. they are found at the beginning of the food chain.

day 188 – @Luke5SOS ‘bile’ is a fluid that is made and released by the liver and stored in the gallbladder. Bile helps with digestion. it breaks down fats into fatty acids, which can be taken into the body by the digestive tract.

day 189 – @Luke5SOS ‘uvula’ a fleshy extension at the back of the soft palate which hangs above the throat.

day 190 – @Luke5SOS ‘aquaporins’ also called water channels, are integral membrane proteins from a larger family of major intrinsic proteins that form pores in the membrane of biological cells, mainly facilitating transport of water between cells.

day 191 – @Luke5SOS ‘capillary action’ is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. plants use capillary action to draw water upwards, i.e. from the root through the xylem vessels.

day 192 – @Luke5SOS ‘carbon cycle’ continuous movement of carbon between different living organisms and between living organisms and the environment, through natural processes like photosynthesis, respiration, and decomposition in the soil, and also the burning of fossil fuels

day 193 – @Luke5SOS ‘chromatin’ is a substance within a chromosome consisting of DNA and protein. the DNA carries the cell's genetic instructions. the major proteins in chromatin are histones, which help package the DNA in a compact form that fits in the cell nucleus

day 194 – @Luke5SOS ‘external fertilisation’ is a case in which fusion of male and female gametes takes place in outside environment/ medium and not in the body of the female. for example, in frogs the female releases eggs in the water at the same time sperms are released too.

day 195 – @Luke5SOS ‘barr body’a small, densely staining structure in the cell nuclei of females, consisting of a condensed, inactive X chromosome. it is regarded as diagnostic of genetic ‘femaleness’

day 196 – @Luke5SOS ‘endospore’ a resistant asexual spore that develops inside some bacteria cells.

day 197 – @Luke5SOS ‘macroevolution’ major evolutionary change, especially with regard to the evolution of whole taxonomic groups over long periods of time.

day 198 – @Luke5SOS ‘mesenchyme’ is a type of connective tissue found mostly during embryonic development of bilateral animals (triploblasts). it is composed mainly of ground substance with few cells or fibers.

day 199 – @Luke5SOS ‘notochord’ a cartilaginous skeletal rod supporting the body in all embryonic and some adult chordate animals.

day 200 – @Luke5SOS (c’mon pls follow it’s been 200 days of me tweet u random biology words) ‘phagocytosis’ a process in which phagocytes engulf and digest microorganisms and cellular debris; an important defense against infection

day 201 – @Luke5SOS ‘zygospore’ the thick-walled resting cell of certain fungi and algae, arising from the fusion of two similar gametes.

day 202 – @Luke5SOS ‘agglutination’ is the clumping of particles. agglutination is the process that occurs if an antigen is mixed with its corresponding antibody called isoagglutinin. this term is commonly used in blood grouping.

day 203 – @Luke5SOS ‘saprophyte’ a plant, fungus, or microorganism that lives on dead or decaying organic matter.

day 204 – @Luke5SOS ‘periostracum’ the external, outermost covering of the shell of some mollusks. it helps to protect the slender slimy inner portions as well as provides the shell with colour.

day 205 – @Luke5SOS ‘vesicle’ is a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. vesicles form naturally during the processes of secretion (exocytosis), uptake (endocytosis) and transport of materials within the plasma membrane

day 206 – @Luke5SOS ‘steroid hormone’ is a steroid that acts as a hormone. they can be grouped into two classes: corticosteroids and sex steroids.

day 207 – @Luke5SOS ‘poikilothermic’ (of all animals except birds and mammals) having a body temperature that varies with the temperature of the surroundings

day 208 – @Luke5SOS ‘skeleton’ an internal or external framework of bone, cartilage, or other rigid material supporting or containing the body of an animal or plant.

day 209 – @Luke5SOS ‘circulation’
the transport of oxygenated blood through the arteries to the capillaries, where it nourishes the tissues, and the return of oxygen-depleted blood through the veins to the heart, where the cycle is renewed.

day 210 – @Luke5SOS ‘adrenergic nerve fibre’ is a neuron for which the neurotransmitter is either adrenaline (epinephrine), noradrenaline or dopamine. these are released at a location known as the synapse (a junction between the axon of one nerve cell and the dendrite of another)

day 211 – @Luke5SOS ‘receptor potential’ initial response of a receptor cell to a stimulus, consisting of a change in voltage across the receptor membrane proportional to the stimulus strength.

day 212 – @Luke5SOS ‘relative fitness’ the contribution of one genotype to the next generation compared to that of alternative genotypes for the same locus.

day 213 – @Luke5SOS ‘RuBisCO’ ribulose carboxylase, the enzyme that catalyzes the first step (the addition of CO2 to RuBP, or ribulose bisphosphate) of the calvin cycle.

day 214 – @Luke5SOS ‘recombination’ formation of new gene combinations; in eukaryotes, may be accomplished by new associations of chromosomes produced during sexual reproduction or crossing over; in prokaryotes, may be accomplished through transformation, conjugation,transduction

day 215 – @Luke5SOS ‘cholesterol’ is a type of fat found in your blood. the liver makes cholesterol for your body + you can also get cholesterol from foods such as meat, fish, eggs, butter, cheese, and milk.

taking a break from this thread for a while to tweet about more important issues!