Science - Glossary

Question 1

DNA structure

Answer 1

DNA has a double helix shape made of nucleotides.

Question 2

Nucleotides

Answer 2

Made of a sugar, phosphate, and nitrogen base.

Question 3

Complementary base pairing

Answer 3

Adenine pairs with Thymine, Cytosine pairs with Guanine.

Question 4

Gene

Answer 4

A section of DNA that codes for a protein.

Question 5

Chromosome

Answer 5

A long DNA molecule containing many genes.

Question 6

Chromatid

Answer 6

One half of a duplicated chromosome.

Question 7

Centromere

Answer 7

The part of a chromosome that links sister chromatids.

Question 8

Homologous chromosomes

Answer 8

Matching pairs of chromosomes, one from each parent.

Question 9

Different base sequences

Answer 9

Result in different genes and different proteins.

Question 10

Gene location

Answer 10

Each gene has a specific position (locus) on a chromosome.

Question 11

Cell replication

Answer 11

Cells replicate their DNA before division.

Question 12

Mitosis

Answer 12

Process that creates 2 identical diploid body cells.

Question 13

Stages of mitosis

Answer 13

Prophase, Metaphase, Anaphase, Telophase.

Question 14

Purpose of mitosis

Answer 14

Growth, repair, and replacement of body cells.

Question 15

Meiosis

Answer 15

Process that creates 4 non-identical haploid gametes.

Question 16

Haploid

Answer 16

A cell with half the usual number of chromosomes.

Question 17

Diploid

Answer 17

A cell with the full set of chromosomes (homologous pairs).

Question 18

Sexual reproduction

Answer 18

Combines two haploid cells to form a diploid zygote.

Question 19

Allele

Answer 19

Different version of a gene.

Question 20

Dominant allele

Answer 20

An allele that masks the effect of a recessive one.

Question 21

Recessive allele

Answer 21

An allele whose trait is only seen when two copies are present.

Question 22

Genotype

Answer 22

The genetic makeup of an organism (e.g. Bb).

Question 23

Phenotype

Answer 23

The physical appearance of an organism (e.g. brown eyes).

Question 24

Punnett square

Answer 24

A chart used to predict offspring genotypes and phenotypes.

Question 25

Mutation

Answer 25

A change in the DNA sequence.

Question 26

Causes of mutations

Answer 26

Radiation, chemicals, errors during DNA copying.

Question 27

Effects of mutations

Answer 27

Can cause diseases like cancer and genetic disorders.

Question 28

Atom

Answer 28

The smallest unit of an element.

Question 29

Element

Answer 29

A substance made of only one type of atom.

Question 30

Proton

Answer 30

Positively charged particle in the nucleus.

Question 31

Neutron

Answer 31

Neutrally charged particle in the nucleus.

Question 32

Electron

Answer 32

Negatively charged particle in electron shells.

Question 33

Atomic number

Answer 33

Number of protons in an atom.

Question 34

Mass number

Answer 34

Number of protons + neutrons in an atom.

Question 35

Isotope

Answer 35

Atoms of the same element with different numbers of neutrons.

Question 36

Group (periodic table)

Answer 36

Vertical column, shows number of electrons in outer shell.

Question 37

Period (periodic table)

Answer 37

Horizontal row, shows number of electron shells.

Question 38

Electron configuration

Answer 38

Arrangement of electrons in an atom’s shells (e.g. 2,8,8,2).

Question 39

Electron configuration for first 20 elements

Answer 39

2, 8, 8, 2.

Question 40

Ion charge prediction

Answer 40

Based on group number in the periodic table.

Question 41

Ionic bond

Answer 41

Transfer of electrons between a metal and a non-metal.

Question 42

Covalent bond

Answer 42

Sharing of electrons between non-metals.

Question 43

Electron-dot diagram

Answer 43

Shows covalent bonds using dots for shared electrons.

Question 44

Structural formula

Answer 44

Shows how atoms are connected in a molecule.

Question 45

Chemical formula

Answer 45

Tells the number and types of atoms in a molecule.

Question 46

Scalar

Answer 46

A quantity with size only (e.g. speed, distance).

Question 47

Vector

Answer 47

A quantity with size and direction (e.g. velocity, displacement).

Question 48

Distance

Answer 48

Total path length an object travels.

Question 49

Displacement

Answer 49

Straight-line distance from start to finish with direction.

Question 50

Speed

Answer 50

Distance divided by time.

Question 51

Velocity

Answer 51

Displacement divided by time.

Question 52

Acceleration

Answer 52

Change in velocity divided by time.

Question 53

Distance-time graph

Answer 53

Shows how distance changes over time, slope = speed.

Question 54

Speed-time graph

Answer 54

Shows how speed changes over time, slope = acceleration.

Question 55

Area under speed-time graph

Answer 55

Represents distance travelled.

Question 56

Newton’s First Law

Answer 56

An object stays at rest or moves at constant speed unless acted on by a force.

Question 57

Newton’s Second Law

Answer 57

Force = mass × acceleration (F = m × a).

Question 58

Newton’s Third Law

Answer 58

Every action has an equal and opposite reaction.

Question 59

Speed formula

Answer 59

Speed = distance ÷ time.

Question 60

Acceleration formula

Answer 60

Acceleration = (change in velocity) ÷ (change in time).

Question 61

Force formula

Answer 61

Force = mass × acceleration (F = m × a)