Bio year 10

Mitosis

Cell division that produces two diploid cells which are genetically identical to each other and to the parent cell.

Meiosis

Cell division that produces four haploid cells which are genetically unique.

Crossing over

A process occurring in meiosis, where genetic material is exchanged between homologous chromosomes.

Gametes

The haploid sex cells (sperm and ova) formed during the process of meiosis.

Haploid

Cells containing only one complete set (n) of chromosomes.

Diploid

Cells containing two complete sets (2n) of chromosomes.

Asexual reproduction

A type of reproduction that does not involve gametes and produces genetically identical offspring.

Sexual reproduction

A type of reproduction which involves gametes and produces genetically unique offspring.

Gonads

Organs that produce gametes in males and females (i.e. testes & ovaries).

Fertilisation

The uniting of two gametes to produce a zygote.

Zygote

The diploid cell formed during the process of fertilisation.

Gene

A section of DNA which codes for the production of a polypeptide and determines a characteristic.

Allele

The alternate forms of a gene, found at the same location on homologous chromosomes.

Genotype

The combination of alleles present for a particular gene in an organism.

Phenotype

The physical expression of a genotype.

Dominant

An allele that masks the presence of a recessive allele.

Recessive

An allele that is masked when in the presence of a dominant allele.

Homozygous

Having identical alleles for a single gene. Example: RR (_______ dominant) or rr (______ recessive).

Heterozygous

Having two different alleles for a single gene.

Monohybrid cross

A cross between two organisms involving a single gene.

Pedigree

A chart used to depict relationships between organisms.

Genetics

The study of heredity.

DNA

Deoxyribonucleic acid, the molecule found within the nucleus which carries genetic information.

Double helix

The twisted structure formed by double-stranded DNA.

Nucleotides

Molecular building blocks of DNA consisting of a sugar, phosphate and nitrogenous base.

Polymerase

The enzyme responsible for synthesising new DNA/RNA.

Helicase

The enzyme responsible for unzipping the double-stranded DNA during replication process.

Polypeptide

A chain of amino acids connected by peptide bonds.

Transcription

Process that occurs in the nucleus where DNA is copied into an mRNA molecule.

Translation

Process where a ribosome synthesises a polypeptide chain using an mRNA molecule.

Codon

A group of three nucleotides on a strand of mRNA that codes for a specific amino acid in the formation of a polypeptide.

messenger RNA (mRNA)

A strand of RNA used to carry information from the nucleus to a ribosome.

transfer RNA (tRNA)

A molecule responsible for carrying amino acid to ribosomes.

Chromatin

A complex of DNA and proteins that forms chromosomes.

Chromosome

A thread-like structure that consists of condensed chromatin.

Homologous chromosomes

A matching pair of chromosomes, one derived from each parent.

Mutation

A change in the genetic information.

Biotechnology

Any technological applications that uses plants, animals or microorganisms to make or modify products or processes that benefit humans.

Clone

A genetically identical cell or organism.

Transgenic organism

An organism that has had genes from other species inserted into its genome.