Regents Review

Day 4Unit 7: Genetics

Unit 8: DNA to Proteins

61.If organisms mate, parents will each pass 50% of the alleles on to their offspring.a. Alleles – different forms of a geneb. Dominant allele – allele that shows up if presentc. Recessive allele – allele can be covered up by a

Dominant allele, need to inherit 2 recessive alleles to see the trait

d. Homozygous – organism inherited two of the same alleles (AA or aa)

e. Heterozygous (hybrid) – organism inherited two different alleles (Aa)

62.Punnet Square – chart used to predict the possible offspring of a crossa. Segregation – alleles separate from each other when

separated in a gameteb. Place possible alleles on the top and side of the punnet

square and crossc. Ex. Cross two hybrid organisms =

63.Pedigree chart – family history that shows the inheritance of a trait

a. Dominant pattern – trait appears in every generation (person with the trait has at least one parent who shows the same trait)

b. Recessive pattern – trait appears to skip generations (person with the trait may have 0, 1, or 2 parents that show the same trait)

c. Autosomal inheritance pattern – occurs equally between men and women

d. Sex-linked inheritance pattern – occurs more often in men (men only have 1 X chromosome)

64.Genetic diseases are inherited through DNA codes and are transmitted from parents to offspring during sexual reproductiona. If an individual inherits two recessive alleles for a trait

they will have the trait

65.Each chromosome holds hundreds of genesa. Down Syndrome is a genetic disease caused by non-

disjunction of chromosomes (extra 21st chromosome)b. This is diagnosed with a karyotype – picture of

homologous chromosomes

66.DNA controls cellular activity by controlling the production of proteins, therefore the phenotype (physical traits) of the organism

67.DNA replication involves making an identical copy of cell’s DNA.a. Replication makes the chromosome

number remain constant from one generation to the next

b. Replication involves matching complimentary nucleotides base pairing rules (A-T & G-C)

c. DNA is made up of many units, called nucleotides, wound together into a double strand that has the shape of a double helix

68.During DNA replication, the original strand of DNA “unzips” when weak hydrogen bonds between the bases of the double strand are brokena. Two new double strands of DNA

result, each has one old and one new strand

69.Information transfer in the cell goes from DNA to RNA to a Proteina. DNA therefore has the original set of instructions for

the order of amino acids that make up a protein

70.DNA is transcribed into mRNA (AUCG)a. Occurs in the nucleusb. Copied in groups of 3’s called codons

71.mRNA is translated into amino acids (then folded into proteins)a. Occurs in the cytoplasm

at the ribosomeb. mRNA Codons are

translated into Amino Acids using the Amino Acid Codon Chart

c. Sequence of Amino Acids determines the SHAPE and the FUNCTION of the Protein

72.DNA mutations may result in the production of abnormal proteins that do not function correctly, or in protein production being stopped.a. These proteins have a different SHAPE, so they have a

DIFFERENT FUNCTION