Biology (Genetics) - NCEA L1

bases of DNA

the base pairing rule

threadlike structures made of DNA molecules that contain the genes

A molecule containing the genetic information that makes up the chromosomes.

double helix

Basic units of DNA molecule, composed of a sugar, a phosphate, and one of 4 DNA bases

the semi-conservative process of the production of identical copies of DNA molecules.

An enzyme unwinds the parent DNA strand by breaking the hydrogen bonds between bases.

Enzymes bond the nucleotides together to form a new strand.

New nucleotides bond with the bases on the parent DNA molecule.

At the end of the process, two molecules of DNA have been produced.

Complimentary base pairing ensures the correct nucleotide goes in the right place.

A segment of DNA on a chromosome that codes for a specific trait

An organism's genetic makeup, or allele combinations.

An organism's physical appearance, or visible traits.

A long chain of amino acids that are chemically bonded together.

building blocks of proteins

Different forms of a gene

Both alleles (factors) for a trait are the same and dominant (AA)

Both alleles (factors) for a trait are the same and recessive (aa)

An organism that has two different alleles for a trait

One allele is from your mother, one from your father.

a pair of chromosomes, one from each parent, that have relatively similar structures and gene values

cells are able to grow and then divide to form two 'daughter' cells

Before mitosis begins the chromosomes are not visible. Also invisible is the process of replication of the cell's DNA. Two copies will be required for each of the two daughter cells.

The DNA condenses into large chromosomes that are visible under a light microscope. The nuclear membrane disappears.

The chromosomes line up in random order in the middle of the cell. Fibres stretch across the cell to pull the chromatids apart.

The fibres pull the chromatids apart and they move to the ends of the cell.

The fibres disappear and a nucleus reforms. The chromosomes begin to uncoil and disappear from view. The center of the cell contracts, beginning the process of forming two separate cells.

The cell membrane and cytoplasm separates into two separate daughter cells.

Used for growth and the repair of damaged cells

Cell division that produces reproductive cells in sexually reproducing organisms

23

reproductive or sex cells

diagram showing the gene combinations that might result from a genetic cross

The Punnett square only shows the chances of what might occur each time an event is undertaken.

A picture of all the chromosomes in a cell arranged in pairs

23 pairs

X and Y

XY

XX

the offspring of many generations that have the same traits

showed dominant vs. recessive genes. (a+a and A+A homozygous A+a heterozygous)

A chart which shows several generations of related families and how traits are passed down through the offspring.

Open Circle

Closed Circle

Open Square

Closed Square

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

sexual reproduction

differences in physical traits of an individual from the group to which it belongs