Oxford Insight Science, Stage 5: Chapter 11 - Genetics and Biotechnology

From - Oxford Insight Science for NSW Stage 5 Student book, 2nd Edition - Chapter 11: Genetics and Biotechnology

gamete

a sex cell containing half the number of chromosomes of other body cells

sperm

the male gamete of animals

ovum

the female gamete of animals and some plants

haploid

a nucleus that contains one complete set of chromosomes; usually found in a gamete

diploid

a nucleus that contains two complete sets of chromosomes

meiosis

the process that results in the formation of gametes with half the genetic material of the parent cell

deoxyribonucleic acid (DNA)

a molecule that contains all the instructions for every job performed by the cell; this information can be passed from one generation to the next

nucleotide

the building block of DNA consisting of a deoxyribose sugar

adenine

a nucleotide of DNA or RNA; complementary to thymine in DNA and uracil in RNA

guanine

a nucleotide of DNA or RNA; complementary to cytosine

cytosine

a nucleotide of DNA or RNA; complementary to guanine

thymine

a nucleotide of DNA; complementary to adenine

complementary base

a nucleotide base that pairs with its partner nucleotide on the alternative DNA strand. Adenine pairs with thymine

ribonucleic acid (RNA)

a complementary copy of DNA that is able to carry the genetic message from the nucleus to the cytoplasm

bivalent chromosome

a chromosome that has duplicated

chromatid

one half of a duplicated chromosome

karyotype

the arrangement of a complete set of chromosomes in pairs of decreasing size

gene

a specific sequence of DNA that codes for a particular trait

transcription

the formation of complementary RNA from DNA

codon

sequence of 3 nitrogen bases in RNA

translation

the formation of a protein from RNA; occurs on a ribosome

principle of segregation

pairs of gene variants are separated into reproductive cells

principle of independent assortment

the inheritance of one set of factors from one parent is separate from the inheritance of other factors

mutagen

a chemical or physical agent that causes a change in DNA

genetic mutation

a permanent change in the sequence of nucleotides in DNA

allele

a version of a gene. Each person inherits one allele from each parent

homozygous

having two identical alleles for a particular trait

heterozygous

having two different alleles for a particular trait; a carrier for the recessive trait

dominant trait

a characteristic that needs only one copy of an allele to appear in the physical appearance of an organism

recessive trait

a characteristic that results from the inheritance of two identical alleles

carrier

a person who is heterozygous and therefore has one recessive allele that is not expressed in their phenotype

genotype

the combination of alleles for a particular trait

phenotype

the physical characteristics that result from an interaction between the genotype and the environment

punnett square

a diagram that is used to predict the outcome of breeding organisms

autosome

a chromosome that does not determine the sex of an organism

sex chromosome

a chromosome that determines the sex of an organism

pedigree

a diagram showing the inheritance pattern of a particular trait

vector

an agent (often a bacteria or virus) used to deliver a trans-gene

genetic screening

the testing of a cross section of individuals to determine whether they have a particular trait or disease

gene probe

short sections of nucleotides known to be complementary to the genetic sequence of interest

genetic testing

the testing of an individual to determine whether they have a particular trait or disease

stem cell

a cell that can produce a number of different types of cells. Adult stem cells can produce a limited number of cell types (e.g. skin stem cells)

gene cloning

to insert a gene into bacteria so that the bacteria now produce a human protein that can be purified and used to treat a human disease

gene therapy

the insertion of a healthy gene into the chromosomes of an individual with a defective gene

zygote

a fertilised diploid egg cell

structure of DNA

double helix

genetic code

the sequence of nucleotides found in DNA that is inherited from parents

point mutation

occurs when one nitrogen base is substituted for another

frameshift mutation

occurs when a nitrogen base is inserted or deleted

monohybrid cross

a genetic mix between two organisms that are both heterozygous for a single specific trait

gmo

genetically modified organism

gmo advantage

enhance certain desired traits

gmo disadvantage

less biodiversity, accidental gene transfer to other species, evolution of pests

somatic cell

a body cell

transgenic organism

an organism with DNA from a different species inserted into its genome