I need help with gentics stuff.

1. Mendel predicted that there are “units of heredity.” We now know that this is a segment of DNA on a chromosome that codes for a particular trait is called a: gene
   
   
2. A version or variant of a gene that produces a specific trait is called an: allele
   
   
3. A recessive phenotype can only be displayed if the genotype is:
   
   
4. When the alleles on homologous chromosomes switch places during meiosis and create recombinant chromosomes, this is called:
   
   
5. When genes are located on the same part of the chromosome, do not assort independently, and get passed on together, the genes are said to be:
   
   
6. Most sex-linked genes are on the _X__ chromosome, simply because they are built of much more DNA.
   
   
7. Sex-linked traits are more common in _X chromosome__ than _the Y chromosome__.