Genetics Flashcards
What order are the phases?
IPMAT
Interphase (Cell spends most of time growing), Prophase (Cell prepares for nucleus division), Metaphase (Cell prepares chromosomes for division), Anaphase (Chromosomes divide), Telophase (Cytoplasm divides, two nucleus’s start to form)
Adenine
The base that combines with thymine to form a base pair
Allele
A version of a gene
An organism gets two alleles of each gene – one from its mother and one from its father.
Amino acid
A small molecule that joins with others to form proteins
Anaphase
A stage of cell division in which the chromosomes separate
Base
Part of a DNA molecule that comes in four types: A, C, G and T
Base pair
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.
Cell cycle
The repeated process of cell growth and division
Cell division
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.
Chromosome
A DNA molecule that condenses during cell division
Most human cells contain 46 chromosomes but sex cells only contain 23 chromosomes.
Crossing over
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.
Cytosine
The base that combines with guanine to form a base pair
Daughter cell
Any new cell formed by cell division
Each daughter cell has its own nucleus and set of DNA.
DNA
A molecule that contains genetic information
DNA, or deoxyribonucleic acid, is a very large molecule that contains instructions for building proteins.
Dominant allele
A version of a gene that is expressed even when only one copy is present (Capital letter)
Dominant trait
A feature that appears when at least one allele is present
Dominant traits include freckles, dimples and the ability to roll your tongue.
Double helix
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.
Fertilisation
The joining of an egg and a sperm to form a new organism
Fertilisation combines DNA from the mother and father so the child gets half of its chromosomes from each parent.
Gene
A unit of genetic information
A gene is a section of a DNA molecule that provides instructions for building a specific protein.
Generation
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.
Genotype
A pair of alleles that influence the appearance of a particular trait
A genotype is represented by two letters. An organism’s genotype determines which traits it acquires – its phenotype.
Guanine
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.
Heterozygous
A genotype in which the two alleles are different
A heterozygous genotype consists of one dominant allele and one recessive allele – Yy.
Homologous pair
Two chromosomes that contain versions of the same genes
One chromosome in a homologous pair is inherited from the mother and the other from the father.