xmas biology

5. a change in the DNA sequence
6. the physical expression of a genotype
10. a nitrogenous base found in RNA that replaces thymine and pairs with adenine
11. a sugar found in milk
12. an enzyme that breaks down lactose into simpler sugars
13. an allele that is expressed only when two copies are present
14. a nitrogenous base found in DNA and RNA that pairs with guanine
15. a nitrogenous base found in DNA that pairs with adenine
17. DNA sequences that provide instructions for making proteins
22. a nitrogenous base found in DNA and RNA that pairs with cytosine
24. DNA sequences that do not code for proteins but can regulate gene expression
25. a nitrogenous base found in DNA and RNA that pairs with thymine in DNA and uracil in RNA
27. process in which ribosomes read mRNA and build a protein

1. process of copying a gene’s DNA sequence into mRNA
2. having two identical alleles for a gene
3. cell organelle that contains DNA and is where transcription occurs
4. cell structure where mRNA is translated into a protein
6. a molecule made of amino acids that performs most cell functions
7. a protein that speeds up chemical reactions in cells
8. different forms of the same gene
9. having two different alleles for a gene
14. a tightly coiled structure of DNA and proteins that carries genes
16. messenger RNA that carries a copy of genetic instructions from DNA to the ribosome
17. a three-nucleotide sequence on mRNA that codes for a specific amino acid
18. an allele that is expressed when at least one copy is present
19. two nitrogen bases held together by hydrogen bonds in DNA
20. a segment of DNA that codes for a protein or trait
21. the genetic makeup of an organism
23. genetic material that stores instructions for making proteins and determining traits
26. the twisted ladder shape of DNA