Year 11 Elevate Science EOY Exam Flashcard

Hydrocarbons

Hydrocarbons are organic compounds composed solely of hydrogen and carbon atoms.

Organic Compound

An organic compound is a substance that contains carbon atoms and is typically found in living organisms.

Complete Combustion

Complete combustion occurs with sufficient oxygen: Fuel + oxygen → carbon dioxide + water.

Incomplete Combustion

Incomplete combustion occurs with limited oxygen: Fuel + oxygen → carbon monoxide + water + carbon (soot).

Alkanes vs Alcohols

Alkanes release more heat per unit of carbon compared to alcohols.

Greenhouse Gases

Certain gases in the atmosphere—like carbon dioxide (CO₂), methane (CH₄), and water vapor (H₂O)—absorb and re-radiate infrared radiation from the sun.

Combination Reaction

A combination reaction, also known as a synthesis reaction, is a chemical reaction where two or more reactants combine to form a single, new substance.

General Form of Combination Reaction

The general form is A + B → AB, where A and B represent reactants, and AB represents the product.

Displacement Reaction

A displacement reaction is a chemical reaction where one element replaces another element in a compound.

Single Displacement Reaction

A single displacement reaction involves one element replacing another in a compound.

Activity Series

The activity series is used to predict whether a displacement reaction will occur and to identify the products of the reaction.

Spectator Ion

In a displacement reaction, a spectator ion is an ion that exists in the same form on both the reactant and product sides of the chemical equation.

Key Characteristics of Spectator Ions

Spectator ions are present in the same form on both sides of the equation, do not affect the outcome of the chemical reaction, and help maintain charge balance in the solution.

Combustion of Alkanes vs Alcohols

Alkanes typically require a higher ignition temperature compared to alcohols.

Conditions for Complete Combustion

Complete combustion requires sufficient oxygen.

Conditions for Incomplete Combustion

Incomplete combustion occurs under limited oxygen conditions.

Precipitation reaction

A type of chemical reaction where two soluble ionic compounds react in a solution to produce an insoluble solid, called a precipitate.

Solubility rules

Guidelines that help predict whether a precipitate will form when mixing solutions.

Insoluble

A term indicating that a compound does not dissolve in a solvent, leading to the formation of a precipitate.

Endemic

A term describing a species that is found naturally in only one specific geographic region.

Niche

The role and position a species occupies in its ecosystem, encompassing its interactions with other species and its environment.

Adaptation

A characteristic or trait that has evolved in an organism over time to help it survive and reproduce in its specific environment.

Structural Adaptations

Physical features of an organism that enhance survival.

Behavioural Adaptations

Actions or patterns of activity that improve survival or reproduction.

Physiological Adaptations

Internal body processes that support survival.

Kiwi's habitat

Native forests, scrublands, and grasslands of New Zealand.

Kiwi's diet

Omnivorous, but mainly insectivorous.

Kiwi's behavior

Nocturnal: Active at night, which reduces competition with diurnal species.

Kiwi's reproduction

Lays large eggs relative to body size, nesting in burrows or hollow logs, with males often incubating the eggs.

Ionic Equations

Equations that show the complete ionic form of the reactants and products, with spectator ions crossed out to show only the species that have reacted.

Balanced molecular equation

An equation that shows the reactants and products of a chemical reaction with the same number of each type of atom on both sides.

Net ionic equation

An equation that shows only the species that have actually reacted, excluding spectator ions.

Precipitate

An insoluble solid that forms when two soluble ionic compounds react in solution.

Observations in reactions

Changes in color, temperature, or formation of a solid that indicate a chemical reaction has occurred.

DNA

DNA, or DeoxyriboNucleic Acid, is the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.

Eukaryotic Cells

In eukaryotic cells (like human and kiwi cells), DNA is found in the nucleus. A eukaryote is any cell or organism that possesses a clearly defined nucleus.

Structure of DNA

DNA is shaped like a double helix, resembling a twisted ladder. It's made of nucleotides, each consisting of a sugar (deoxyribose), a phosphate group, and a nitrogenous base (Adenine [A], Thymine [T], Cytosine [C], Guanine [G]).

Structure of DNA Nucleotide

DNA is a molecule made of many repeating units of nucleotides. Each nucleotide consists of a common sugar and phosphate group with one base attached to the sugar.

Function of DNA

DNA stores genetic information. It provides instructions for making proteins. Proteins perform the functions of cells. DNA is replicated during cell division so each new cell has the same genetic material.

Double Helix Structure

DNA's double helix is made of two strands twisted around each other. The presence of two strands allows for efficient DNA repair.

Nitrogenous Bases

The nitrogenous bases (A, T, C, G) store genetic information in sequences, like letters in a code.

DNA Coiling and Packaging

DNA wraps around proteins which are tightly packed into chromosomes. This compact structure allows large amounts of DNA to fit inside a tiny cell nucleus.

DNA Flexibility

DNA can unzip in small sections to allow enzymes to read or repair it. This flexibility is crucial for making new DNA and also for DNA repair.

Genes

Genes are segments of DNA that contain the instructions for building and maintaining an organism. They act like a biological code or recipe that tells cells how to make proteins, which carry out most of the functions in the body.

Chromosomes

Chromosomes are long, thread-like structures made of genes (DNA and proteins) that carry genetic information.

Codons

Genes are made up of a specific sequence of nucleotides (A, T, C, G). These sequences are in groups of three called codons.

Chromosome

They are found in the nucleus of cells and are essential for inheritance, cell division, and the functioning of organisms.

Kiwi chromosomes

Kiwi birds have 80 chromosomes arranged into 40 pairs.

Human chromosomes

Humans have 46 chromosomes arranged into 23 pairs.

Alleles

Alleles are different versions or forms of the same gene.

Gene

A gene is a segment of DNA that codes for a trait (like eye colour).

Homozygous

Both alleles are the same (e.g., AA or aa).

Heterozygous

The alleles are different (e.g., Aa).

Dominant allele

A dominant allele shows its effect even if only one copy is present (e.g., Aa, aA, AA).

Recessive allele

A recessive allele only shows its effect if both copies are the same (e.g., aa).

Mutation

A mutation is a permanent change in the DNA sequence.

Causes of mutations

Mutations can happen naturally or be caused by environmental factors like stress, radiation, chemicals, or viruses.

How mutations create new alleles

Mutations create new alleles by changing the DNA sequence of a gene.

Mutations role in evolution

Mutations introduce new alleles into a population and are the raw material for natural selection and evolution.

Genotype

A genotype is the complete set of genetic information an organism carries for a particular trait.

Phenotype

A phenotype is the set of observable traits or characteristics of an organism that result from the interaction of its genotype with the environment.

Examples of phenotypes

Physical traits: Eye colour, height, skin tone, flower colour; Behavioural traits: Nesting habits, vocalizations; Physiological traits: Blood type, metabolism rate.

Environmental factors influencing phenotypes

Phenotypes can be influenced by environmental factors such as nutrition, climate, lifestyle, and exposure to chemicals or stress.

Meiosis

Meiosis is a special type of cell division that produces gametes—sperm and egg cells—in sexually reproducing organisms.

Purpose of meiosis

To produce gametes with half the usual number of chromosomes and to enable genetic diversity through crossing over and independent assortment.

Gamete

A gamete is a reproductive cell (sperm or ova) that can unite with another gamete to form a new organism.

Zygote

A zygote is the first cell that is formed when a sperm and an ova fuse during fertilization.

Crossing Over

Crossing over is the exchange of genetic information between paired chromosomes (one from each parent) creating new allele combinations.

Independent Assortment

Independent assortment is the separation of chromosomes into new gamete cells, where chromosomes are randomly distributed.

Fertilization

Fertilization combines two gametes to form a zygote which contains two alleles for each gene—one from each parent.

Inheritance

Inheritance is the process by which genetic information is passed from parents to offspring.

Dominant Gene

A dominant gene shows its trait even if only one copy is present, usually represented by a capital letter (e.g., A).

Recessive Gene

A recessive gene only shows its trait if both copies are recessive, represented by a lowercase letter (e.g., a).

Punnett Square

A Punnett square is a simple diagram used in genetics to predict the possible combinations of alleles that offspring might inherit from their parents.

Phenotypic Ratio

Phenotypic ratios describe the relative frequencies of different phenotypes in a population.

Genotypic Ratio

Genotypic ratios describe the relative frequencies of different genotypes in a population.

Genetic Variation Definition

Genetic variation refers to the differences in DNA sequences among individuals within a population.

Sources of Genetic Variation

Sources of genetic variation include mutations, meiosis, fertilization, and gene flow.

Mutations

Mutations are random changes in DNA that can create new alleles and can be beneficial, harmful, or neutral.

Meiosis Contribution to Variation

During gamete formation, meiosis mixes genetic material through crossing over and independent assortment.

Gene Flow

Gene flow is the movement of genes between populations, introducing new alleles into a population.

Effects of Mutations in Kiwi

In kiwi, mutations can create new alleles of existing genes and alter traits like beak shape, feather colour, or disease resistance.

Natural selection

The process by which organisms with traits that are better suited to their environment tend to survive and reproduce more successfully than others.

Evolution

The process by which living organisms change over time through changes in their genetic material.

Bottleneck effect

Occurs when a population experiences a sharp reduction in size due to a random event, drastically reducing genetic diversity.

Inbreeding

Maintaining variation is critical in small or endangered populations to avoid inbreeding and genetic bottlenecks.

Speciation

The development of new species over long periods due to gradual changes in populations.

Allele

A variant form of a gene that can influence traits such as feather color in kiwis.

Advantageous traits

Traits that help survival and are passed to offspring through genes.

Reduced genetic variation

Can make the population more vulnerable to disease, environmental changes, and inbreeding.

Kiwi population decline

Kiwi populations have decreased from an estimated 12 million before human arrival to about 68,000 today.

DNA sequencing

The process of determining the exact order of the nucleotides (A, T, C, and G) in a DNA molecule.

Genetic markers

Specific sequences in DNA that can be used to identify individuals, track inheritance, or study genetic variation.

Genome

The complete set of genetic material in an organism, including all of the organism's DNA.

Non-coding DNA

DNA that doesn't make proteins but can regulate gene activity.

Function of the genome

Controls traits and characteristics, guides cell functions and development, and stores hereditary information.

Kiwi genome size

Estimated to be around 1.5 billion base pairs, larger than many other bird genomes and even the human genome.

Unique features of kiwi genome

Includes nocturnal adaptations, inactivated colour vision genes, strong sense of smell, and faster-evolving mitochondrial genes.

Monitoring genetic diversity

Genome data helps measure genetic variation within and between kiwi populations, crucial for disease resistance and adaptability.

Detecting harmful mutations

DNA sequencing can identify harmful mutations that may affect survival or reproduction of the kiwi.