Genetics 1
Where in the cell is genetic information found?
The nucleus
The complete set of genes in a cell or organism is called?
The Genome
What is a chromosome?
Packages of DNA, containing genes/genetic material.
What is the full name of the carrier of genetic information?
Deoxyribonucleic Acid (DNA)
What is a gene and what does it code for?
A length of DNA that codes for one protein
What are the building blocks of DNA called and what are they composed of?
Nucleotides; sugar, phosphate and base
Define inheritance
The process by which genetic information is passed from parents to their offspring.
Define homologous chromosomes
Homologous chromosomes are pairs of chromosomes that have the same structure and carry the same types of genes. They may have different alleles for these genes.
Different versions of a gene are called?
Alleles
Alleles can either be _____ or ______
Dominant or recessive
How many copies of a dominant allele are needed for a trait to be expressed?
How many copies of a recessive allele are needed for a trait to be expressed?
Two
What is the definition of homozygous?
Chromosomes have two IDENTICAL alleles of a particular gene or genes
What is the definition of heterozygous?
Chromosomes have two DIFFERENT alleles of a particular gene or genes
Gregor Mendel's famous experiment with peas showed us that?
Traits can skip a generation. I.e. the principal of inheritance.
What is genetic variation?
Genetic variation is the difference in DNA sequences between individuals within a population
What are the two key sources of genetic variation?
What is the definition of a mutation?
A mutation is a permanent change to the DNA sequence of an organism.
What is the only way to produce new alleles?
Mutation
Why is genetic variation useful?
Genetic variation is useful because it helps populations change over time. Variations that help an organism survive and reproduce are passed onto the next generation.
Variations that hinder survival and reproduction are eliminated from the population.
What is the difference between a continuous and discontinuous trait?
Measurable or countable traits vs described, not measured
How are continuous traits inherited?
Polygenic inheritance- multiple genes interacting together
Environmental factors- diet, physical activity etc.
What are the two ways that meiosis produces genetic variation? What are their definitions?
Crossing over- exchange of genetic information between non-sister chromatids of homologous chromosomes
Independent assortment- the random alignment and distribution of chromosomes during meiosis.
Discontinuous traits often follow _____ inheritance patterns, where the ratio of phenotypes in offspring can be predicted based on the genotypes of the _____.
Mendelian and parents
What is the purpose and goal of meiosis?
The production of gametes with half the number of chromosomes as the starting cell.