Year 10 Science Biological Sciences Review

Vocabulary flashcards covering the Year 10 Science Unit 3 Biological Sciences learning objectives including reproduction, cell division, DNA, genetics, inheritance, and evolution.

Asexual reproduction

A form of reproduction involving a single parent that produces offspring genetically identical to the parent.

Sexual reproduction

A form of reproduction involving the combination of genetic material from two parent organisms or gametes to produce genetically unique offspring.

Gametes

Specialized sex cells (such as sperm and egg cells) containing a haploid set of chromosomes.

Somatic cells

All body cells of an organism excluding reproductive cells (gametes), which contain a diploid set of chromosomes.

Mitosis

A type of cell division that results in two daughter cells each having the same number and set of chromosomes as the parent cell, used for growth and repair.

Meiosis

A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, producing gametes.

Diploid

Refers to a cell containing two complete sets of chromosomes, represented as $2n$.

Haploid

Refers to a cell containing a single set of unpaired chromosomes, represented as $n$.

Nucleotide

The basic subunit of DNA consisting of three components: a sugar, a phosphate group, and a nitrogenous base.

Autosomes

Chromosomes that carry traits unrelated to sex determination, present in equal numbers in males and females.

Sex chromosomes

Chromosomes that determine the biological sex of an individual (e.g., X and Y chromosomes).

Karyotype

A visual representation or image of the complete set of chromosomes in a cell, used to determine chromosome count, sex, and structural mutations.

Chargaff's rule

The principle of complementary base pairing in double-stranded DNA stating that adenine pairs with thymine ($A = T$) and cytosine pairs with guanine ($C = G$).

Transcription

The process of copying a specific sequence of DNA into a complementary mRNA strand in the nucleus.

Translation

The process where mRNA is decoded by ribosomes to form a sequence of amino acids for protein synthesis.

Germline mutation

A mutation occurring in reproductive cells (gametes) that can be inherited by offspring.

Somatic mutation

A mutation occurring in non-reproductive body cells that cannot be passed to future generations.

Point mutation

A gene mutation involving a change in a single nucleotide base within a DNA sequence, including substitutions, insertions, and deletions.

Silent mutation

A point mutation that changes a codon to another codon that specifies the exact same amino acid, causing no change to the resulting protein.

Missense mutation

A point mutation where a single base substitution alters a codon to code for a different amino acid in the protein sequence.

Nonsense mutation

A point mutation that converts an amino acid codon into a premature stop codon, terminating protein translation early.

Frameshift mutation

A mutation caused by the insertion or deletion of nucleotides not in multiples of three, shifting the reading frame of the genetic sequence.

Genotype

The specific combination of alleles or genetic makeup of an individual organism.

Phenotype

The observable physical or functional traits of an individual resulting from the interaction of its genotype with the environment.

Dominant allele

An allele that masks the expression of a recessive allele and determines the phenotype in both homozygous and heterozygous genotypes.

Recessive allele

An allele whose phenotypic effect is masked in the presence of a dominant allele and is expressed only when homozygous.

Homozygous

Having two identical alleles for a given gene on homologous chromosomes.

Heterozygous

Having two different alleles for a given gene on homologous chromosomes.

Monohybrid cross

A genetic cross or mating experiment focused on studying the inheritance pattern of a single trait.

Pedigree diagram

A chart showing genetic relationships and inheritance patterns of specific traits across multiple generations of a family.

Evolution

The process of change in the genetic material and inherited traits of biological populations over time.

Gene flow

The movement and exchange of genetic material (alleles) between different populations of the same species.

Independent assortment

The random alignment and separation of different gene pairs during meiosis, contributing to genetic variation in gametes.

Natural selection

The mechanism of evolution where environmental conditions favor individuals with advantageous heritable traits, increasing their survival and reproductive success.

Artificial selection

The intentional breeding of plants or animals by humans to select for specific desirable phenotypic traits.

Homologous structures

Anatomical body parts in different species that share a common evolutionary origin and structural blueprint, even if they perform different functions.

Analogous structures

Anatomical features in different species that perform similar functions but evolved independently without a common ancestral origin.

Biogeography

The study of the geographic distribution of living organisms and fossils across the Earth over time.