Genetics, Natural Selection and Evalution - The Basics Of Genetics Flashcards
What is DNA?
DNA is short for deoxyribonucleic acid. It is a molecule that is found in all of the cells in your body and contains genes.
What are genes?
Genes are regions of DNA that contain the instructions for making a protein. Proteins are molecules that are involved in most of our bodies’ functions.
Where is DNA found?
It is found in a cells nucleus and is coiled into structures called chromosomes.
What is a karyotype?
It is a picture of all the chromosomes removed from one cell
How many pairs of chromosomes do humans have in a cell?
23 pairs
How many chromosomes do humans have in one cell?
46
Where do organisms chromosomes come from?
From it’s parents through sexual reproduction.
The DNA that makes up genes consists of repeats of 4 different letters – _____, _____, _____and _____
A, C, G, T
Different forms of a gene are called ______________
Alleles
The gene copy (allele) for detached earlobes (which we will call “D”) is dominant to the copy for attached earlobes (“d”). What would happen if your mom gave you the “d” allele and your dad also gave you the “d” allele?
You would have attached earlobes!
What if both parents gave you the “D” allele?
You would have detached earlobes!
An organism that has 2 IDENTICAL copies (or alleles) of a gene is considered to be _________________ for that gene, (e.g. DD, dd).
HOMOZYGOUS
An organisms that has 2 DIFFERENT copies (or alleles) of a gene is considered to be ________________, for that gene (e.g. Dd).
HETEROZYGOUS
The combination of alleles that an organism has is called its ___________, (e.g. Dd).
genotype
The way the organisms looks is called its ____________, (e.g. detached earlobes).
phenotype
Phenotype is determined by ____________!
Genotype
Usually letters are chosen based on the __________ trait.
dominant
For the __________ trait, it is represented
by the same letter used to represent the
dominant trait however it will be a ________ case letter.
recessive, lower
When filling in the middle boxes in the Punnett square, the _________ trait is written before the __________.
dominant, recessive
Define Heredity
The passage of genetic information from a parent or parents to offspring
Define Hybrid
The offspring of genetically different parents. For example, the offspring of pure FF and ff parents is an Ff hybrid.
Define inheritance
The passage of genetic material from parents to offspring. Ex/ for each gene, an organism receives one allele from each parent.
Define trait
A characteristic of an organism. Examples of traits include skin colour, eye colour, hair, allergies, and many others.
