Definitions

Question 1

When is a measurement valid?

Answer 1

When it measures what it is supposed to be measuring

Question 2

What is repeatability?

Answer 2

How precise repeated measurements are when when they are taken by the same person using the same equipment under the same conditions

Question 3

What is reproducibility?

Answer 3

How precise repeated measurements are when they are taken by different people using different equipment

Question 4

What is the uncertainty of a measurement?

Answer 4

The interval within which the true value is expected to lie

Question 5

Define measurement error

Answer 5

The difference between a measured value and the true value

Question 6

What type of error is caused by results varying around the true value in an unpredictable way?

Answer 6

Random error

Question 7

What is a systematic error?

Answer 7

A consistent difference between the measured values and the true values

Question 8

What does zero error mean?

Answer 8

A measuring instrument gives a false reading when the true value should be zero

Question 9

Define a fair test

Answer 9

A test in which only the independent variable is changed

Question 10

what is a null hypothesis?

Answer 10

States there is no significant difference between two populations

Question 11

Continuous variation

Answer 11

Data that can take any value on a sliding scale e.g height, mass

Question 12

Discontinuous variation

Answer 12

Data can not be sorted into discrete categories

Question 13

Interspecific variation

Answer 13

Differences between organisms of difference species

Question 14

Intraspecific variation

Answer 14

Differences between organisms of the same species

Question 15

What is a normal distribution

Answer 15

A normal distribution in graphs has a bell shaped curve which is symmetrical (Mean, median and mode are equal)

Question 16

What is suspension?

Answer 16

A mixture in which particles are dispersed throughout the bulk of a fluid.

Question 17

What does the term Degenerate mean in terms of Genetic code?

Answer 17

An amino acid may be specified by more than one type of codon (A set of three adjacent nucleotides in mRNA)

Question 18

What does the term ‘non-overlapping’ mean in terms of genetic code?

Answer 18

Each base in the sequence is read only once

Question 19

What does the term universal mean in terms of genetic code?

Answer 19

Each triplet codes for the same amino acid in all organisms.

Question 20

Definition of a gene?

Answer 20

A sequence of DNA which codes for a polypeptide

Question 21

Codon

Answer 21

Three bases that code for a specific protein.

Question 22

Introns

Answer 22

Left over combinations; do not code for proteins.

Question 23

Locus

Answer 23

A particular position on a particular chromosome where a gene sits.

Question 24

Histone

Answer 24

The protein that DNA coils around to fit in a cell. Together these form chromatin (what chromosomes are made of)

Question 25

Alleles

Answer 25

Different versions of genes

Question 26

Homologous chromosomes

Answer 26

Two chromosomes that carry the same genes but not necessarily the same alleles of the genes.

Question 27

Sister chromatids

Answer 27

Two copies of the same chromosomes held together by the centromere.

Question 28

Chromatid

Answer 28

One copied section of DNA

Question 29

Apoptosis

Answer 29

Cell death

Question 30

Pathogens

Answer 30

Disease causing microorganisms

Question 31

Genome

Answer 31

Complete set of genes in a cell

Question 32

Proteome

Answer 32

Full range of proteins a cell can produce

Question 33

Locus

Answer 33

Location of a gene

Question 34

When a genetic code is degenerate

Answer 34

More than one triplet codes for the same amino acid. (This reduces the number of mutations caused by substitution, deletion and insertion)

Question 35

Histones

Answer 35

Proteins in eukaryotic cells to form structures called chromosomes. This is the result of the DNA being tightly compiled around the histones.

Question 36

Introns

Answer 36

A segment of a DNA or RNA molecule which does not code for proteins

Question 37

Exons

Answer 37

A segment of a DNA or RNA molecule containing information coding for a protein.

Question 38

Polyploidy

Answer 38

An individual has three or more sets of chromosomes instead of two

Question 39

Non-disjunction

Answer 39

Occurs when chromosomes fail to separate correctly in meiosis As a result the gametes will have one more or one less chromosome than they should

Question 40

Genetic diversity

Answer 40

Total number of different alleles in the population

Question 41

Population

Answer 41

Defined as a group of individuals of the same species that live in the same place and are able to breed

Question 42

Niche

Answer 42

The species role within the environment

Question 43

Natural selection

Answer 43

The process in which fitter individuals who are better adapted to the environment survive and pass on there advantageous genes to future generations by reproduction.

Question 44

Directional selection

Answer 44

Occurs when the environmental conditions change and the phenotypes best suited to the new conditions are more likely to survive. As a result these individuals will breed and produce offspring.

Question 45

Stabilising selection

Answer 45

The phenotypes with successful characteristics are preserved and those of greater diversity are reduced. This selection does not occur due to changes in the environment. The furthest from the mean are selected against.

Question 46

Anatomical adaptations

Answer 46

Physical adaptations either external or internal

Question 47

behavioural adaptationos

Answer 47

Changes in behaviour which improve the organisms chance to survive

Question 48

Physiological adaptations

Answer 48

Processes inside an organisms body that increases its chance of survival e.g. regulation of blood flow through the skin

Question 49

Diploid

Answer 49

A cell with a full set of chromosomes

Question 50

Haploid

Answer 50

A cell with no pairs of homologous chromosomes so an odd number of chromosomes

Question 51

Homologous chromosomes

Answer 51

Pair of the same chromosome. Genes are the same but the alleles are different

Question 52

Sister chromatids

Answer 52

The copy (Half old, half new)

Question 53

Species richness

Answer 53

Number of different species in a community

Question 54

Genetic bottleneck

Answer 54

An event that causes a big reduction in a population and reduces genetic diversity.

Question 55

Founder effect

Answer 55

The reduction in genetic diversity that occurs when just a few organisms from a population start a new colony.