science revision y10

Fossil

The preserved remains or traces of ancient organisms, usually found in sedimentary rocks.

Phylum

a group of related animals or plants classified under a single category in biological taxonomy.

Compression Fossils

are formed when organic materials are buried under layers of sediment and subjected to pressure, resulting in a two-dimensional imprint of the original organism.

Impression Fossils

are created when an organism is buried in sediment, and its shape is preserved as a three-dimensional impression in the surrounding material.

Premineralised Fossils

These fossils occur when minerals fill in the spaces within an organism's remains, preserving its structure.

Mould Fossils

Mould fossils are formed when an organism leaves an impression in the sediment, creating a hollow mold that can be filled in by other materials to create a cast.

Cast Fossils

Cast fossils are formed when an organism decays after being buried, leaving a mould that is later filled with minerals, creating a replica.

Sedimentary Rocks

are types of rocks formed from the accumulation and compaction of mineral and organic particles, typically in layers.

Relative age

The age of a fossil determined through comparing other fossils.

Absolute age

The numeric age of a fossil, uses methods like radiometric dating to calculate a fossil’s actual age based on decay of radioactive elements.

Radiometric dating

Radiometric dating uses the known decay rates of radioactive isotopes to determine the age of materials.

Benefit of Radiometric dating

Helps to establish the geological timescale and understand the age of rocks and fossils.

Amber fossil

Organisms trapped in tree resin that hardens into amber.

Collision theory

Collision theory states that for a reaction to occur, reactant particles must collide with sufficient energy and proper orientation.

Effects of changes in surface area of a solid on the rate of a reaction.

Increasing the surface area of a solid reactant increases the reaction rate because more particles are exposed, leading to more frequent collisions with reactant molecules.

how collison theory applies to chemical reaction

Increasing the frequency and effectiveness of collisions increases the reaction rate.

Effects of changes in temperature on the rate of a reaction

Raising the temperature increases the kinetic energy of particles, causing more frequent and energetic collisions, making it more likely for collisions to exceed the activation energy required for a reaction.

Effects of changes in concentration on the rate of a reaction

Higher concentration of reactants leads to a greater number of particles in a given volume, increasing the likelihood of collisions and thus speeding up the reaction.

Effect of a catalyst on a reaction rate.

A catalyst speeds up a reaction by providing an alternative pathway with lower activation energy, allowing more successful collisions to occur without being consumed in the reaction.

Explain that a catalyst speeds up a reaction but is not a reactant itself

A catalyst is not consumed in the reaction; it remains unchanged at the end of the process. It lowers activation energy, allowing the reaction to proceed faster without being altered chemically.

the general shape of a graph plotting the amount of product versus time over a period of a reaction.

The graph typically starts with a steep increase, gradually leveling off as reactants are consumed. A fast reaction has a steeper curve, while slower reactions have a more gradual incline.

Conditions for living things to fossilise.

Rapid burial to protect remains from decay, low oxygen conditions to slow decomposition, pressure and mineralisation over time to preserve structures.

Carbon imprint

thin, carbon residue left behind after organic matter decomposes.

Deduce the relative age of fossills

Fossils found in lower rock layers are older than those in higher layers. Index fossils can help estimate ages of rock layers.

Evolution

The process of gradual change in species over time due to genetic variations and environmental pressures.

Biological fitness

The ability of an organism to survive and reproduce, passing its genes to the next generation.

Natural Selection

The process where individuals with advantageous traits are more likely to survive and reproduce, leading to changes in a population over generations.

Justify why Lamarck’s proposed mechanism for evolution was first considered then rejected.

Lamarck proposed that organisms could change during their lifetime by using or not using certain traits and pass those acquired traits to their offspring. It was later rejected because traits acquired during life are not inherited genetically.

Charles Darwin

Developed the theory of natural selection through observations from his voyage on the HMS Beagle. Published On the Origin of Species in 1859.

Alfred Wallace

Developed the idea of natural selection through studies in the Malay Archipelago, co-publishing early findings with Darwin before Darwin’s full work was released.

Explain how new species evolve.

New species form through speciation, which occurs when populations become isolated due to geographic, behavioral, or genetic barriers. Over time, genetic differences accumulate, preventing interbreeding and leading to the formation of distinct species.

the process of natural selection using examples.

Natural selection favours individuals with beneficial traits that help them survive and reproduce. For example, peppered moths before industrial pollution, light-coloured moths blended into trees and were less likely to be eaten. As pollution darkened trees, dark moths became better camouflaged, leading to an increase in their population.

importance of variations in the process of evolution.

Variations provide a genetic pool for natural selection to act upon. Some offers survival advantages, helping organisms adapt to changing environments. Without variation, evolution would be slow, and species might struggle to survive environmental changes.

how fossil record provides evidence for evolution.

The fossil record shows gradual changes in species over time, revealing transitional forms that link different groups and demonstrating how organisms have evolved.

Define ‘transitional form’ and explain how transitional forms support the theory of evolution.

A transitional form is a fossil that shows features of both ancestral and descendant species. These fossils provide evidence for evolution by demonstrating gradual changes between species.

Comparative anatomy

Identifies homologous structures (similar body parts in different species) that indicate common ancestry.

Comparative embryology

Shows similarities in early embryo development across species, supporting evolutionary links

examples of molecular biology techniques and how they are used to determine evolutionary relationships.

DNA sequencing and protein analysis

assess the importance of biodiversity to the long-term survival of species.

Biodiversity increases adaptability, providing species with genetic variation that helps them survive environmental changes, resist disease, and avoid extinction.

What genetic diversity in species that reproduce sexually?

Genetic recombination, meiosis, and mutations.

What genetic diversity in species that reproduce asexually?

Mutations and horizontal gene transfer.

The potential impact of reproductive technologies and genetic engineering on genetic diversity.

can reduce genetic diversity by favouring specific traits, limiting variation, and affecting species adaptability.

Conduction

Heat transfer through direct contact between particles.

Convection

Heat transfer through fluid movement, where warmer particles rise and cooler particles sink.

Longitudinal waves

Particles move parallel to wave direction (e.g., sound waves).

Transverse waves

Particles move perpendicular to wave direction (e.g., light waves).

Frequency

Number of waves passing a point per second.

Wavelength

Distance between two consecutive crests or troughs.

Speed

How fast the wave travels through a medium.

how the ear functions to provide hearing.

The ear converts sound waves into electrical signals:

1. Sound waves vibrate the eardrum.

2. Vibrations pass through the middle ear bones.

3. Cochlea converts vibrations into nerve signals sent to the brain.

Identify visible light as a form of electromagnetic radiation.

Visible light is part of the electromagnetic spectrum and consists of different wavelengths perceived as colors by the human eye.

Identify the properties of electromagnetic waves.

Electromagnetic waves:

• Travel through a vacuum.

• Have both electric and magnetic components.

• Vary in wavelength and frequency across the electromagnetic spectrum.