Test Flashcards
(39 cards)
Gene
A gene is a unit of heredity information. Made from DNA
Alleles
Allele is a genetic sequence. They also code for transmission of traits. Variant of a gene
Dominant
A genetic trait is considered dominant if it is expressed in a person with only one copy of that gene
Recessive
A gene which can be masked by a dominant gene. Expressed if the person has two copies
Pedigree chart
Genetic representation of a family tree that diagrams the inheritance of a trait or disease through several generations. Shows which individual express or silently carry trait
Meiosis
Process in which gametes (sex cells) are generated in oganisns that reproduce sexually. Division of sex cells into 4 daughter cells
Mitosis
The genetic material from the cell is duplicated and divided into two genetically identical cells. Division of body cells into 2 daughter cells
Theory of evolution
Charles Darwin. Living things can change.
All vertebrates use same set of parts to build body.
All sexually reproducing organisms start as one cell. Common origin
All aerobic organisms use oxygen to get energy via respiration. Even use same enzymes
Lower rock layers are older. Fossils become fewer and simpler
Ingredient for evolution
Time. Population with variation Isolation Environmental stress Natural selection combined with mutation
Atomic theory
All matter is made up of tiny indivisible particles called atoms.
Smallest object that retains properties of element.
Atoms are composed of electrons and nucleus
The nucleus contains protons and neutrons
Can it be created or destroyed
Protons
A stable subatomic particle occurring in all atomic nuclei with a positive electrons charge equal in magnitude to that of an electron
Electron
A stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.
Neutron
A subatomic particle of about the same mass as a proton bit without an electric charge, present in all atomic nuclei except those of ordinary hydrogen.
Atomic number
the number of protons of an atom, which is characteristic of a chemical element and determines its place in the periodic table.
Atomic mass
The mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons.
Ion
an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. If an element has two electrons in outer shell it loses it to become 2+ ion
Isotope
Isotopes are atoms with the same number of protons but a different number of neutrons. Can be unstable/radioactive
period
Horizontal row on the periodic table. 7 periods. Amount of electron shells. Top has one going down to 7.
group
Vertical row on the periodic table. They have similar chemical behaviour. Number of electrons in outer shell.
Factors affecting rate of reaction
Temperature
Pressure
Concentration
Catalyst: a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
Newtons laws + application to life
1) An object at rest will remain at rest and an object in 1) 1) motion will remain in motion unless acted upon by an external, unbalanced force.
2) F=ma
3) For every action there is an equal and opposite reaction
life cycle of star
star nebula: average star-red giant- nebula- white dwarf
star nebula: massive star- red supergiant- supernova-neutron star or black hole
formation of a star
1) clouds of dust and gas are disturbed by the gravity of a nearby phenomina
2) clumps of hydrogen form
3) enough hydrogen causes it to heat up and the gas fuses producing helium and energy. ignites
Galaxy
a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.
