16. Chromosomes, Genes And Proteins Flashcards
Chromosome
A length of dna found in the nucleus of a cell that contains genetic info in the form of many diff genes
Largest to smallest cell structures
Cell nucleus chromosome DNA molecule gene
DNA
A molecule that’s contains genetic information in the form of genes that controls the proteins made in a cell
Gene
A length of dna that codes for one protein
Alleles
Alternative forms of a gene
Reduction division
A term used to describe what happens in meiosis where the number of chromosomes is halved
Homozygous
Having two identical alleles of a particular gene (ex. GG or gg)
Heterozygous
Having two different alleles of a particular gene (ex Gg)
Genotype
The genetic makeup of an organism in terms of the alleles present
Phenotype
The observable features of an organism
Dominant allele
An allele that is expressed if it is present
Recessive allele
An allele that is only expressed when there is no dominant allele so the gene present
Codominanace
alleles that are both expressed in phenotype when they are both present
Inheritance
The transmission of genetic info from generation to generation
Genetic diagram
A standard way of showing all the steps in making predictions about the possible genotypes and phenotypes of the offspring from the two parents
Monohybrid cross
A cross where we consider the inheritance of only one gene
Punnet square
A part of a genetic diagram that shows the predicted genotypes and phenotypes that can result from the random fusion of the male and female gamete
Test cross
A cross used to determine the genotype of an organism showing the characteristic produced buy a dominant allele
Sex chromosome
Chromosomes that determine sex
X chromosome
The larger of the two sex chromosomes in mammals
Y chromosome
The smaller of the two sex chromosomes in mammals
Sex linked genes
Genes that are found on a part of one of the sex chromosome (usually X) and not on the other sex chromosome they therefore produce characteristics that are more common in one sex than the other
Messenger RNA (mRNA)
A molecule that carries a copy of information on dna to a ribosome to be used or synthesise a protein
Expressed
Used it make a protein - a gene is expressed when the protein that is codecs for is synthesised in a cell
Stem cells
Unspecialised cells that are able to divide by mitosis to produce different types of specialised cells [ex. Blood stem cell to rbc]
