G&D - T9-13

What two ways do organisms reproduce?

Asexual and Sexual reproduction

Compare and contrast asexual and sexual reproduction.

Asexual reproduction involves one parent and produces identical offspring quickly, while sexual reproduction involves two parents, creates genetically diverse offspring, and takes more time and energy.

How is genetic information transferred from parent to offspring?

Each parent transferres 1/2 of chromasomes (Asexual is 1/1) to the child. Chromasomes contain DNA, which holds genes (instructions for traits) and alleles, variations of the genes.

What is genetic variation?

Variation of the genes passed down, can prevent against genetic problems.

Allele

an alternate form of a gene for a specific trait, described as either dominant or recessive

Dominant

describes the allele that determines the trait when two different forms are present

Recessive

descrives the allele that is not expressed when combined with a dominant form of the gene, trait only shows if the organism has two recessive alleles

Protein

large molecules that do much of the work in a cell and also make up much of the cell's structure, responsible for most aspects of how our bodies function, as well as for our physical appearance and our behavior.

Homozygous

the same allele combination, dom or res.

Heterozygous

two different alleles, dom and res

Purebred

type of organism whose ancestors are genetically the same

Hybrid

Offspring of crosses between parents with different traits

Punnett Square

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

Genotype

genetic makeup of an organism

Phenotype

physical characteristics of an organism

Gene

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

Chromasome

A structure in the nucleus made up of DNA which bears the genetic information of an organism. 1/2 passed on from both parents.

DNA

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

How to use a punnet square?

1. determine the genotypes of the parent organisms

2. write down your "cross" (mating)

3. draw a p-square

4. "split" the letters of the genotype for each parent & put them "outside" the p-square

5. determine the possible genotypes of the offspring by filling in the p-square

6. summarize results (genotypes & phenotypes of offspring)