Year 10 Revision Week 5 Notes

Flashcards covering revision notes for Year 10 Biology, Chemistry, and Physics topics including human evolution, atomic structure, and waves.

Binomial system

The naming system published by Carl Linnaeus that uses two Latin words, the genus and the species, to identify organisms.

Fossil record

The collection of fossils from different periods in Earth’s history that reveals details about how organisms have changed gradually through time.

Ardi

A $4.4$ million year old human-like species (Ardipithecus ramidus) discovered in 1992 with a brain size of $350\,cm^{3}$ and chimpanzee-like features.

Homo habilis

An extinct human-like species nicknamed ‘the handy man’ who existed $2.4-1.4$ million years ago and was the first to make primitive stone tools.

Cranial capacity

The measurement of brain size, which has increased over the evolution of human-like species, suggesting more complex central nervous systems.

Natural selection

The process defined by Charles Darwin and Alfred Russel Wallace where individuals with better-adapted variations are more likely to survive, breed, and pass on their traits.

Selection pressure

Environmental conditions, such as competition or predation, that lead to the survival of only the best-adapted individuals in a population.

Antibiotic resistance

A modern-day example of natural selection where bacteria naturally resistant to drugs survive and reproduce, causing infections that cannot be treated.

Molecular phylogeny

The study of DNA, genes, and proteins in organisms to track similarities and work out how closely related two species are.

Archaea

A domain consisting of cells with no nucleus where genes contain unused sections of DNA.

Animalia

A kingdom of multicellular heterotrophic organisms with complex cell structures, a nucleus, and no cell walls.

Selective breeding

The process where humans choose parents with useful characteristics to breed the next generation to achieve a high quality yield.

Genetic engineering

The process of removing a gene from one organism and inserting it into the DNA in a cell from another organism.

Restriction enzymes

Enzymes used in genetic engineering to isolate a gene or cut open a plasmid by making staggered cuts labeled 'sticky ends'.

Ligase

An enzyme used to join the complementary sticky ends of a desired gene and a plasmid together.

Vector

In genetic engineering, an organism (like a bacterium or plasmid) that carries genetic information into another cell.

World Health Organisation (WHO)

The organization responsible for coordinating international health improvements, defining health as a state of complete physical, social, and mental well-being.

Communicable disease

A disease caused by pathogens, such as bacteria or viruses, that can be spread from person to person.

Lysozyme

A chemical barrier consisting of enzymes found in tears that kills microorganisms.

Malnutrition

A condition occurring from getting too little or too much of particular nutrients, which can lead to deficiency diseases like scurvy or rickets.

Kwashiorkor

A deficiency disease caused by a lack of protein, characterized by an enlarged belly and small muscles.

Body Mass Index (BMI)

An estimate of body fat calculated using the formula $\text{BMI} = \frac{\text{mass}\,(kg)}{(\text{height}\,(m))^{2}}$.

Atheroma

A fatty deposit found on the artery wall made of cholesterol, white blood cells, and calcium ions that can lead to cardiovascular disease.

Pathogen

A disease-causing organism, categorized into bacteria, viruses, protists, and fungi.

Antigen

Specific particles on the outer surface of a cell that the immune system uses to identify foreign cells.

Memory lymphocytes

White blood cells that remain in the bloodstream after an infection to respond rapidly if the same pathogen re-enters the body.

Vaccine

A substance containing weakened or inactive sections of a pathogen used to trigger an artificial primary immune response for immunity.

Isotopes

Different atoms of an element with the same number of protons and electrons but different numbers of neutrons.

Mendeleev

A chemist who organized the first periodic table by increasing atomic mass and left gaps for undiscovered elements.

Cation

A positively charged ion formed when a metal atom loses its outermost electrons.

Anion

A negatively charged ion formed when a non-metal atom gains electrons.

Ionic bond

The strong electrostatic force of attraction between oppositely charged ions in a lattice structure.

Covalent bond

The sharing of pairs of electrons between non-metal atoms.

Allotropes

Different structural forms of the same element, such as diamond, graphite, and graphene for carbon.

Avogadro's constant

The number of particles in one mole of any substance, which is $6.02 \times 10^{23}$.

Limiting reactant

The reactant that is used up completely in a chemical reaction and determines the amount of product formed.

Transverse wave

Waves, such as light or sea waves, in which particles oscillate at right angles to the direction of energy transfer.

Longitudinal wave

Waves, such as sound waves, in which particles oscillate back and forth in parallel with the direction of energy transfer.

Refraction

The change in direction of light when it moves into a different material of different density due to changes in wave speed.

Gamma rays

The electromagnetic waves with the shortest wavelength and highest frequency, used in cancer treatment and sterilization of equipment.