terms

Question 1

allele

Answer 1

A version of a gene

An organism gets two alleles of each gene - one from its mother and one from its father.

Question 2

adenine

Answer 2

The base that combines with thymine to form a base pair

Adenine is one of the four letters that make up the genetic code in humans and other living things.

Question 3

amino acid

Answer 3

A small molecule that joins with others to form proteins

Amino acids are the building blocks of proteins, which are the building blocks of cells.

Question 4

anaphase

Answer 4

A stage of cell division in which the chromosomes separate

Anaphase is when the chromosomes separate and are pulled away from each other to opposite sides of the cell.

Question 5

base

Answer 5

Part of a DNA molecule that comes in four types: A, C, G and T
Bases join together in pairs to form the ‘rungs’ of the DNA molecule.

Question 6

base pair

Answer 6

Two bases joined together

Base pairs form in only two combinations: A-T or G-C. These are the letters that make up the genetic code.

Question 7

cell cycle

Answer 7

The repeated process of cell growth and division

During most of the cell cycle, a cell grows and performs its function. This ends when the cell divides by mitosis.

Question 8

cell division

Answer 8

The splitting of a cell to form new cells

Cell division allows organisms to grow, repair damage and reproduce. There are two types: mitosis and meiosis.

Question 9

chromosome

Answer 9

A DNA molecule that condenses during cell division

Most human cells contain 46 chromosomes but sex cells only contain 23 chromosomes.

Question 10

crossing over

Answer 10

The swapping of genes between chromosomes in a homologous pair
Crossing over only occurs in meiosis, during prophase I. It increases the genetic variety of the sex cells produced.

Question 11

cytosine

Answer 11

The base that combines with guanine to form a base pair

Cytosine is one of the four letters that make up the genetic code in humans and other living things.

Question 12

DNA

Answer 12

A molecule that contains genetic information

DNA, or deoxyribonucleic acid, is a very large molecule that contains instructions for building proteins.

Question 13

dominant trait

Answer 13

A feature that appears when at least one allele is present

Dominant traits include freckles, dimples and the ability to roll your tongue.

Question 14

daughter cell

Answer 14

Any new cell formed by cell division

Each daughter cell has its own nucleus and set of DNA.

Question 15

dominant allele

Answer 15

A version of a gene that is expressed even when only one copy is present
A dominant allele is represented by an uppercase letter. Yy or YY will result in the appearance of the Y trait.

Question 16

dominant trait

Answer 16

A feature that appears when at least one allele is present

Dominant traits include freckles, dimples and the ability to roll your tongue.

Question 17

double helix

Answer 17

A structure consisting of two chains twisted around each other
The DNA molecule has a double helix structure. The ‘rungs’ connecting the two chains are base pairs.

Question 18

fertilization

Answer 18

The joining of an egg and a sperm to form a new organism

Fertilization combines DNA from the mother and father so the child gets half of its chromosomes from each parent.

Question 19

guanine

Answer 19

The base that combines with cytosine to form a base pair

Guanine is one of the four letters that make up the genetic code in humans and other living things.

Question 20

gene

Answer 20

A unit of genetic information

A gene is a section of a DNA molecule that provides instructions for building a specific protein.

Question 21

generation

Answer 21

Members of a family that are born and live at about the same time
Traits are passed down from one generation to the next by the transfer of DNA from parents to children.