Topic 3 Flashcards
Chromosome
In nuclei of cells
Contains long DNA molecule packed with proteins
Daughter cell
Cell produced by other cell that has divided
Diploid
Cell w 2 sets of chromosomes
DNA
Deoxyribonucleic Acid
Polymer made of glucose and phosphate joined to bases
Gene
Section of the long DNA strand in a chromosome
Contains instructions for proteins
Genome
All of the DNA in an organism
Meiosis
Cell division in one parent cell to produce 4 haploid daughter cells
Mitosis
Cell division to form two diploid daughter cells
Polymer
Molecule made up of a chain of repeating similar sub units (monomers)
Adenine
Base
Paired with thymine
Base
Four substances that help make up DNA
A & T
C & G
Complementary base pairs
Pairs of bases that fit into each other
Cytosine
Base
Paired with guanine
Double Helix
Two helixes joined together - shape of DNA
Guanine
Base
Paired with cytosine
Hydrogen bond
Weak force of attraction caused by differences in electrical charges in different parts of different molecules
Thymine
Base
Paired with adenine
Allele
Different versions of a gene
E.g. eye colour
Dominant
Alleles that will always affect the phenotype
Genetic diagram
Shows how alleles of two parents may form different combinations
Genetic variation
Differences in organisms passed on from parents
Genotype
Alleles for certain characteristics found in an organism.
Heterozygous
When alleles are different
Dominant / recessive
Homozygous
When alleles are the same
Dominant / recessive
Monohybrid inheritance
Study of how alleles or just one gene are passed from parent to offspring
Phenotype
Characteristics that a certain set of alleles produce
Recessive
Only affects phenotype if the other allele is also recessive
Family pedigree chart
Chart showing phenotypes and sexes of several generations of a family
Punnet Square
Diagram used to predict characteristics in offspring of two organisms using combinations fo alleles
Sex Chromosomes
Males = one X and one Y
Females = two X and one Y
Human Genome Project
Project mapped base pairs in one human genome
Mutation
A change to a gene, caused by a mistake in copying DNA base pairs during cell division
Variation
Differences
Acquired characteristics
Characteristics that can be changed during life due to environment
Continuous variation
Continuous data taking any value between 2 limits
Discontinuous variation
Data values that can only have one set number of options
Environmental variation
Differences caused by environmental factors
E.g. heat, light, damage
