Year 10 Biology Semester 2: Evolution, Primates, Biotechnology, Cells, and Microscopy

Comprehensive vocabulary flashcards covering the Year 10 Biology Semester 2 curriculum: evolutionary mechanisms, primate and hominin evolution, biotechnology, cell biology, and microscopic calculation techniques.

Evolution

The gradual genetic change in the characteristics of biological populations over successive generations.

Microevolution

Evolutionary changes that occur within a species or population over a short time frame without resulting in the formation of a new species.

Macroevolution

Major evolutionary transitions over geological time that lead to the formation of new species (speciation).

Species

A group of organisms that can interbreed in nature to produce viable, fertile offspring.

Speciation

The evolutionary process by which an ancestral population separates and evolves into distinct, reproductively isolated species.

Reproductive Isolation

The inability of related populations or species to successfully interbreed and produce fertile offspring due to physical, behavioral, or geographical barriers.

Gene Flow

The movement and transfer of genetic information (alleles) between interbreeding populations.

Selection Pressure

Biotic factors (e.g., predation, disease, competition) or abiotic factors (e.g., temperature, water availability, fire) that influence the survival and reproduction of individuals in a population.

Adaptation

A physical or physiological characteristic of an organism that improves its ability to survive and reproduce in a specific environment.

Fossil

The preserved remains, impressions, or traces of past living organisms found in sedimentary rock layers.

Index Fossil

A fossil of an organism that was geographically widespread but existed for only a brief, well-defined geological time period, used to match and correlate rock layers.

Relative Dating

A method of estimating whether a rock layer or fossil is older or younger relative to others based on stratigraphy, assuming deeper rock strata are older than overlying ones.

Absolute Dating

A technique that determines the exact chronological age of a fossil or rock stratum using the decay rates of radioactive isotopes.

Half-Life

The time required for half of the radioactive nuclei in an isotope sample (such as Carbon-14, which has a half-life of $5,730\,\text{years}$) to decay.

Evidence to support theory of evolution: Homologous Structures

Anatomical structures in different species that share a common ancestral origin and structural plan, indicating close evolutionary relationships.

Evidence to support theory of evolution: Vestigial Structures

Body structures reduced in complexity and function that are inherited from an ancestral species in which they were functional.

Evidence to support theory of evolution: Molecular comparison evidence

Comparison of amino acid or DNA base sequences between organisms, where fewer differences signify a more recent common ancestor and closer evolutionary relationship.

Evidence to support theory of evolution: Extinction Events

Mass events in Earth's history where large numbers of species across the globe died out and disappeared from the fossil record over a relatively short period of geological time.

Lamarck's Evolutionary Theory

The early theory proposing that organisms acquire characteristics through the use or disuse of body parts during their lifetime and pass these acquired traits to their offspring.

Natural Selection

The mechanism of evolution described by Darwin and Wallace wherein individuals possessing favourable inherited traits best suited to their environment survive, reproduce, and pass those traits to the next generation.

Overproduction

A premise of natural selection where populations produce more offspring than the environment's resources (food, shelter) can support.

Variation

Differences in phenotypic traits and genetic alleles among individuals within a population.

Artificial Selection

A human-directed process (selective breeding) where humans intentionally choose and breed parent organisms displaying desirable traits over multiple generations.

Antibiotic Resistance

The evolved ability of bacteria to survive antibiotic exposure, resulting from random mutations and selective survival due to antibiotic overuse or misuse.

Primate

A placental mammal distinguished by a relatively large brain, binocular stereoscopic vision, nails instead of claws, and opposable digits.

Hominin

A taxonomic group that includes modern humans (Homo sapiens), extinct ancestral humans, and related upright bipedal species such as the genus Australopithecus.

Hominization

The evolutionary transition and morphological changes involved in the development of human characteristics from ancestral hominin lines.

Bipedalism

A form of terrestrial locomotion where an organism walks upright on two rear limbs or feet.

Stereoscopic Vision

Binocular vision resulting from forward-facing eyes with overlapping visual fields, allowing three-dimensional sight and accurate depth perception.

Opposable Thumb

A thumb that can be brought into contact with other fingertips of the same hand, enabling precise grasping and tool manipulation.

Prosimians

The most primitive primate group, characterized by features including grooming claws, a tooth comb, scent glands, and primarily nocturnal tree-dwelling habits.

New World Monkeys

Arboreal primates from the Americas (e.g., Howler Monkey) characterized by prehensile gripping tails, widely spaced nostrils, and quadrupedal movement.

Old World Monkeys

Primates native to Africa and Asia (e.g., Mandrills) that lack a prehensile tail, have downward-pointing nostrils set close together, and frequently dwell on the ground.

Apes

Tail-less primates with arms longer than legs, prominent bony eye ridges, and quadrupedal knuckle-walking or brachiating locomotion.

Australopithecus

An early hominin genus characterized by habitual bipedalism, a relatively small body size, and a lower cranial capacity compared to the genus Homo.

Homo Genus

The hominin genus characterized by taller posture, a substantially larger brain capacity, reduced canines and eye ridges, and a more parabolic dental arcade.

Foramen Magnum

The large opening at the base of the skull for the spinal cord, which migrated to a more central, forward position underneath the skull to support upright bipedal posture.

Nutcracker Man

A robust early hominin skull (Paranthropus boisei) discovered in 1959 by Louis and Mary Leakey in Olduvai Gorge, Tanzania.

Laetoli Footprints

Fossilized footprints discovered in Tanzania by Mary Leakey proving that Australopithecus walked upright with bipedal locomotion.

Turkana Boy

A nearly complete 1.6-million-year-old fossilized skeleton of Homo erectus discovered by Richard Leakey near Lake Turkana, Kenya.

Biotechnology

The technological application of biological systems, living organisms, or their derivatives to create or modify products and processes.

Recombinant DNA

A DNA molecule formed artificially in a laboratory by combining genetic material from two or more different sources or organisms.

Restriction Enzyme

A bacterial endonuclease enzyme that recognizes and cuts double-stranded DNA at specific nucleotide base-pair sequences.

DNA Ligase

An enzyme that facilitates the joining of cut DNA strands by catalyzing the formation of phosphodiester bonds, effectively gluing genes into plasmids.

Plasmid

A small, circular, self-replicating loop of double-stranded DNA found in bacteria, separate from chromosomal DNA, commonly used as a genetic engineering vector.

Vector

A DNA molecule (such as a plasmid or virus) used as a vehicle to artificially carry foreign genetic material into a host cell.

Gel Electrophoresis

A laboratory method used to separate charged macromolecules (like cut DNA fragments) across an agarose gel matrix using an electric current, separating fragments by size.

DNA Profiling

A technique used to analyze and compare unique banding patterns of fragmented DNA to establish biological relationships or identify suspects from crime scenes.

Genetically Modified Organism (GMO)

An organism whose genome has been deliberately altered using recombinant DNA technology to introduce desired genes.

Prokaryotic Cell

A simple, single-celled organism that lacks a distinct membrane-bound nucleus and internal membrane-bound organelles, typically containing a single circular chromosome.

Eukaryotic Cell

A structurally complex cell that contains a distinct membrane-bound nucleus and specialized membrane-bound organelles.

Nucleus

The eukaryotic organelle bounded by a double nuclear membrane that houses cellular genetic material (chromosomes) and directs cell activities.

Mitochondria

Double-membraned eukaryotic organelles with an inner folded membrane (cristae) that serve as the primary sites of cellular respiration to generate energy.

Chloroplast

A plant organelle with a double membrane enclosing stroma and stacked thylakoid grana containing chlorophyll, serving as the site of photosynthesis.

Rough Endoplasmic Reticulum

A network of parallel tubular membranes studded with ribosomes, functioning in the synthesis, folding, and transport of proteins.

Smooth Endoplasmic Reticulum

A tubular membrane system that lacks attached ribosomes and is involved in lipid metabolism and processing within the cell.

Golgi Apparatus

A stack of flattened membrane-bound sacs that modifies, concentrates, and packages materials received from the endoplasmic reticulum for intracellular use or extracellular export.

Ribosome

A cellular structure composed of RNA and protein, found in both prokaryotes and eukaryotes, that carries out protein synthesis.

Lysosome

A membrane-bound eukaryotic organelle containing digestive enzymes to break down waste, foreign particles, and worn-out cell parts.

Vacuole

A membrane-bound fluid-filled storage sac holding water, nutrients, or wastes; typically occupying up to $90\%$ of mature plant cell volume.

Cell Membrane

A selectively permeable boundary surrounding the cytoplasm that regulates the transport of substances into and out of the cell.

Cell Wall

The rigid external layer composed mainly of cellulose in plant cells (also found in fungal and bacterial cells) providing support and structural integrity.

Total Magnification

The overall power of magnification in a light microscope, calculated by the formula: $\text{Eyepiece Lens} \times \text{Objective Lens}$.

Field of View (FoV)

The diameter or actual width of the circular light area visible through the microscope eyepiece at a particular objective magnification.

Real Life Size (RLS)

The calculated actual size of a microscopic specimen, found by dividing the field of view diameter by the estimated number of cells fitting across the view.

Three Image Alterations by Microscopes

The three standard transformations a light microscope produces on an image: enlargement, reversal, and inversion.

p-Value

A statistical value indicating the probability that experimental differences occurred by random chance; a value of $p < 0.05$ indicates a statistically significant difference.

Evidence to support theory of evolution: Biogeography

The study of the distribution of organisms. Relies on ideas that: organisms originate in a specific area and that they disperse outwards from this area to use available space.

Evidence to support theory of evolution: Fossil evidence

The remains or traces of organisms from the past, providing a historical record of life. Through relative or absolute dating.

How many micrometres are in 1 millimeter (mm)?

1000

What are the magnifications and field of view diameters for our microscopes when using a scanning objective, low power objective and high power objective?

Scanning objective - x4 and 4500 micrometer diameter

Low power objective - x10 and 1800 micrometer diameter

High power objective - x40 and 450 micrometer diameter

Equation for total magnification of an image/microscope

Eyepiece magnification x Objective lens magnification

Equation for field of view diameter

Field number divided by objective magnification

Equation for real-life size of cell

Diameter FOV divided by number of cells that fit across the FOV

Equation for the magnification of a biological drawing

Size of drawing (micrometers) divided by RLS (micrometers)

What makes a good biological drawing

Drawing what is seen, draw the diagram large and in the middle of the page, use clear lines, label to the right side with clear, straight, non-overlapping lines, include a title and indicate magnification