Year 10 Biology Overview (Semester 1, 2026)

Vocabulary flashcards created from the lecture notes covering key biological concepts and terminology.

DNA

A molecule composed of nucleotides that carries genetic information.

Nucleotide

The building blocks of DNA, composed of a phosphate group, deoxyribose sugar, and a nitrogenous base.

Base Pairing Rule

A principle stating that in DNA, adenine pairs with thymine (A-T) and cytosine pairs with guanine (C-G).

Antiparallel

Describes the orientation of the two strands of DNA that run in opposite directions.

DNA Replication

The process by which a cell duplicates its DNA to pass on genetic material during cell division.

Mitosis

A type of cell division that results in two identical diploid daughter cells.

Meiosis

A type of cell division that produces four nonidentical haploid daughter cells, essential for sexual reproduction.

Homozygous

Having identical alleles for a particular gene (e.g., AA or aa).

Heterozygous

Having different alleles for a particular gene (e.g., Aa).

Dominant

An allele that is expressed in the phenotype when at least one copy is present.

Recessive

An allele that is expressed in the phenotype only when two copies are present (homozygous).

Phenotype

The observable traits or characteristics of an organism as determined by its genotype.

Genotype

The genetic makeup of an individual, often represented by allele combinations.

Punnett Square

A grid used to predict the genotypic and phenotypic outcomes of a genetic cross.

Pedigree

A diagram showing the lineage or descent of an individual, often used to track genetic traits.

Natural Selection

The process through which individuals with favorable traits are more likely to reproduce, leading to evolutionary changes.

Mutation

A permanent alteration in the DNA sequence of an organism, which can lead to variations.

Selection Pressure

An environmental factor that influences which individuals reproduce and pass on their genes.

Speciation

The formation of new and distinct species in the course of evolution.

Genetic Diversity

The total number of genetic characteristics in the genetic makeup of a species, important for adaptability.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis, leading to genetic variation.

Independent Assortment

The process by which different genes independently separate from one another when reproductive cells develop.

Allele

A variant form of a gene that can result in different traits.

Prophase

The first stage of mitosis where chromatin condenses into visible chromosomes, and the spindle apparatus begins to form.

Metaphase

The second stage of mitosis in which chromosomes align at the cell's equator, known as the metaphase plate.

Anaphase

The third stage of mitosis where sister chromatids are pulled apart to opposite ends of the cell.

Telophase

The final stage of mitosis where chromosomes de-condense, the nuclear membrane reforms, and the spindle apparatus disassembles.

Cytokinesis

The process that follows mitosis, where the cytoplasm divides, resulting in two separate daughter cells.

Prophase

The first stage of mitosis where chromatin condenses into visible chromosomes, and the spindle apparatus begins to form.

What stage occurs during the alignment of chromosomes at the cell's equator?

Metaphase.

Metaphase

The second stage of mitosis in which chromosomes align at the cell's equator, known as the metaphase plate.

What happens during Anaphase?

Sister chromatids are pulled apart to opposite ends of the cell.

Anaphase

The third stage of mitosis where sister chromatids are pulled apart to opposite ends of the cell.

What occurs during Telophase?

Chromosomes de-condense, the nuclear membrane reforms, and the spindle apparatus disassembles.

Telophase

The final stage of mitosis where chromosomes de-condense, the nuclear membrane reforms, and the spindle apparatus disassembles.

What process follows mitosis and involves the division of the cytoplasm?

Cytokinesis.

Cytokinesis

The process that follows mitosis, where the cytoplasm divides, resulting in two separate daughter cells.

What are sister chromatids?

Identical copies of a single chromosome formed during DNA replication. They are joined at the centromere and are essentially the same DNA, duplicated.

Homologous chromosomes

A pair of chromosomes, one from each parent, that have the same genes in the same order, but can carry different alleles.