9A - Genetics and Evolution Flashcards
abiotic factor
Something that is abiotic has nothing to do with living
organisms (e.g. temperature, the wind).
biotic factor
An activity of an organism that affects another
organism (such as competition or predation).
characteristic
A feature of an organism.
variation
The differences between things.
classification
sorting things into groups.
continuous
Continuous data can take any value between two limits.
Examples include length, mass, time.
continuous variation
When the value of a variable is continuous, it shows
continuous variation.
discontinuous
Data values that can only have one of a set number of
options are discontinuous. Examples include shoe
sizes and blood groups.
discontinuous
variation
When the value of a variable is discontinuous, it shows
discontinuous variation.
environment
The conditions in a habitat caused by physical
environmental factors and living organisms.
environmental factor
Anything that can change the conditions in a habitat or
the organisms that live there.
environmental
variation
Differences between organisms caused by
environmental factors.
physical
environmental factor
A non-living factor that can change the conditions in a
habitat (e.g. amount of light, rainfall).
resource
Something needed by an organism. For example,
plants need light as a resource and animals need food
as a resource.
species
A group of organisms that can reproduce with each
other to produce offspring that will also be able to
reproduce.
genus
A group of similar organisms. The genus name is the
first word in the scientific name for a species (the
second word is the ‘species name’). Different closely
related species belong to the same genus.
fertilisation
Fusing of a male gamete with a female gamete.
fuse
When two things join together to become one.
gamete
A cell used for sexual reproduction. (Sperm or egg cell)
gene
Section of the long strand of DNA found in a
chromosome, which contains instructions for a
characteristic.
genetic information
The inherited instructions that control your
characteristics.
inherit
A feature that an organism gets from a parent is
inherited.
inherited variation
Differences between organisms that are passed on to
offspring by their parents in reproduction.
normal distribution
If the value of a variable changes in a continuous way,
it will often show a normal distribution. This means that
the middle values of the data range are most common
and values at the highest and lowest extremes are least
common. This sort of data forms a bell shape on charts
and graphs.
nucleus
The ‘control centre’ of a cell, where genetic information
is found.
offspring
The new organisms produced by reproduction.
parent
An organism that has produced offspring.
sexual reproduction
Reproduction that needs two individuals to produce a
new organism of the same type.
zygote
term for ‘fertilised egg cell’.
cell division
The splitting of a parent cell to form two identical
daughter cells. The daughter cells both contain the
same genetic information as the parent cell.
chromosome
A structure found in the nuclei of cells. Each
chromosome contains one enormously long DNA
molecule.
DNA
A substance that contains genetic information. Short for
deoxyribonucleic acid.
Sex Chromosomes
Chromosome that determines the sex of an organism.
In humans, males have one X sex chromosome and
one Y sex chromosome, while females have two Xs.
adaptation
The features that something has to enable it to do a
certain job or survive in a particular place.
biodiversity
The range of different species of organisms in an area.
competition
There is competition between organisms that need the
same resources as each other. We say that they
compete for those resources.
ecosystem
All the physical environmental factors and all the
organisms that are found in a habitat.
endangered
When a type of organism is in danger of ceasing to
exist.
extinct
An organism that no longer exists is extinct.
food web
Many food chains linked together, showing the flow of
energy through organisms in a habitat.
gene bank
Any facility that stores genetic material from different
organisms (e.g. seeds, gametes, tissue samples).
native
Naturally found in a certain area.
evolution
A change in one or more characteristics of a population
over a long period of time.
natural selection
A process in which an organism is more likely to
survive and reproduce than other members of the
species because it possesses a certain inherited
variation.
