BIO 325 Exam 2 Study Questions and
Answers Graded A+ 2026
Parental types
Phenotypes that reflect a previously existing parental combination of genes that is
retained during gamete formation
Recombinant types
Phenotypes reflecting a new combination of genes that occurs during gamete
formation
Linked genes
Genes on the same chromosome that do not assort independently
Genetically linked
If the parentals outnumber recombinants
Recombination frequency
Percentage of recombinant progeny; 1% rf= 1 cm = 1 m.u.; 50% limit
Nucleotide
Consists of a deoxyribose sugar, a phosphate, and one of four nitrogenous bases
Phosphodiester bonds
Link nucleotides in a dna chain; form between 3' and 5' carbons
Purines
,Adenine, guanine
Pyrimindine
Thymine, cytosine
5' end
Free 5' carbon atom, may carry either hydroxyl or phosphate
3' end
Free 3' carbon
Hydrogen bonds
Connect the nucleotides
B dna
Spirals right
Z dna
Spirals left, zigzag backbone
Antiparallel
One strand is oriented in the 5′-to-3′ direction, while the other, complementary
strand is oriented in the 3′-to-5′ direction.
Most eukaryotes
Double stranded, linear dna
, Prokaryotes, chloroplasts, mitochondria, and some viruses
Double stranded circular dna
Synthetic genes
Located on the same chromosome
Recombination
Physical exchange of info between homologs
Spo11
Cleaves phosphodiester bond, physically breaks dna backbone
Branch migration
Holliday junctions move away from each other and thereby enlarge the
heteroduplex
Chromosomes
Dna + protein
Histone
Controls overall chromatin environment
Between a &t
2 h bonds
Between g & c
Answers Graded A+ 2026
Parental types
Phenotypes that reflect a previously existing parental combination of genes that is
retained during gamete formation
Recombinant types
Phenotypes reflecting a new combination of genes that occurs during gamete
formation
Linked genes
Genes on the same chromosome that do not assort independently
Genetically linked
If the parentals outnumber recombinants
Recombination frequency
Percentage of recombinant progeny; 1% rf= 1 cm = 1 m.u.; 50% limit
Nucleotide
Consists of a deoxyribose sugar, a phosphate, and one of four nitrogenous bases
Phosphodiester bonds
Link nucleotides in a dna chain; form between 3' and 5' carbons
Purines
,Adenine, guanine
Pyrimindine
Thymine, cytosine
5' end
Free 5' carbon atom, may carry either hydroxyl or phosphate
3' end
Free 3' carbon
Hydrogen bonds
Connect the nucleotides
B dna
Spirals right
Z dna
Spirals left, zigzag backbone
Antiparallel
One strand is oriented in the 5′-to-3′ direction, while the other, complementary
strand is oriented in the 3′-to-5′ direction.
Most eukaryotes
Double stranded, linear dna
, Prokaryotes, chloroplasts, mitochondria, and some viruses
Double stranded circular dna
Synthetic genes
Located on the same chromosome
Recombination
Physical exchange of info between homologs
Spo11
Cleaves phosphodiester bond, physically breaks dna backbone
Branch migration
Holliday junctions move away from each other and thereby enlarge the
heteroduplex
Chromosomes
Dna + protein
Histone
Controls overall chromatin environment
Between a &t
2 h bonds
Between g & c
