Science Exam

Bio, chem, physics

Alleles

alternate genes occupying the same place on an homologous chromosomes

Autosome

Chromosomes other than sex chromosomes

Basic DNA structure

Sugar phosphate-AT or GC

Chromosomes

Protein bodies in the nucleus

Chromatid

Arms of X shapes chromosomes

Diploid

Having 2 sets of Chromosomes

Dominant

The only gene that shows in the offspring

Gamete

Haploid reproductive cell

Genes

A unit of heredity passed down from parent to offspring

Genotype

the genetic constitution of an organism

Haploid

Having only a single set of chromosomes

Heredity

the passing off features from parent to offspring

heterozygous

having 2 different alleles of a particular gene

Homologous

“Paired” chromosomes ie same gene in the same position

homozygous

having identical alleles

Hybrid

heterozygous for the trait in question

Meiosis

the reduction divisions during which the chromosome is halved in forming the gametes

mitosis

The process by which the nucleus is divided in 2 creating 2 daughter nuclei

mutation

anything that happens and effects the hereditary material

Phenotype

The outward expression of a genotype

recessive

an allele if it is expressed only in the homozygous condition

test cross

a cross between an individual displaying a recessive and dominant trait

sex chromosomes

X and Y determine the gender

zygote

a diploid cell produced at fertilization

Atomic number

Number of protons

Mass Number

protons + neutrons

Isotopic notation

an element with its mass number (top) and atomic number (bottom) in the form A X,

Properties of metals

Good conductors of heat and electricity, ductile, malleable,

Properties of Ionic compounds

High melting and boiling points, brittle, does not conduct electricity in solid state but does in a liquid state.

reactivity

the tendency of a subject to undergo chemical reaction

electronegativity

atoms ability to attract electrons

What is metallic bonding

the electrostatic energy between cations and delocalised electrons

Monoatomic ions

ions formed from a single atom

polyatomic ions

ions that are made up of more than one atom

ionic bonding model

3d lattice that is held together by a strong attraction

Why cant ions conduct electricity in a solid state

because in a crystal structure the ions are in a fixed position but when melted or dissolved the ions are freely moving

properties of acids

taste sour, corrosive, pH under 7

Properties of bases

tastes bitter, slippery corrosive, pH over 7

chemical potential energy

the energy stored in the chemical bonds of a substance

exothermic reactions

reactions that release energy

endothermic reactions

reactions that absorb energy

resistance

measure of the opposition to current flow in a circuit

Ohm’s Law meaning

v= voltage, I= current, R= resistance

3 circuit components

path, load, source

conventional current vs electron flow

conventional current flows from the positive terminal while electron flows from the negative

voltage

an electromotive force expressed in volts

Ohm’s Law

V=IR