Bio 109 Exam #4 2024/2025 Exam
Questions Marking Scheme New Update
| A+ Rated
Monohybrid Cross - 🧠ANSWER ✔✔A genetic cross between homozygous
individuals but with different alleles for a single gene
-(Rr x Rr or RR x RR or rr x rr)
Incomplete Dominance - 🧠ANSWER ✔✔the dominant allele does not mask
the recessive allele
Co-Dominance - 🧠ANSWER ✔✔more than one dominant allele
-ex: blood type
Dihybrid Cross - 🧠ANSWER ✔✔A cross between individuals that have 4
alleles for 2 genes
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
1
STATEMENT. ALL RIGHTS RESERVED
, Sex-linked characterisitics - 🧠ANSWER ✔✔genes on the sex
chromosomes
Females - 🧠ANSWER ✔✔have 25% chance of having a characteristic
because they can be carriers without having the characteristic
Males - 🧠ANSWER ✔✔have 50% chance of having a characteristic
DNA - 🧠ANSWER ✔✔-deoxyribonucleic acid
-double stranded
-Sugar: deoxyribose
-Phosphate
-Nitrogenous base:
1. Adenine
2. Thymine
3. Cytosine
4. Guanine
RNA - 🧠ANSWER ✔✔-ribonucleic acid
-single stranded
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
2
STATEMENT. ALL RIGHTS RESERVED
Questions Marking Scheme New Update
| A+ Rated
Monohybrid Cross - 🧠ANSWER ✔✔A genetic cross between homozygous
individuals but with different alleles for a single gene
-(Rr x Rr or RR x RR or rr x rr)
Incomplete Dominance - 🧠ANSWER ✔✔the dominant allele does not mask
the recessive allele
Co-Dominance - 🧠ANSWER ✔✔more than one dominant allele
-ex: blood type
Dihybrid Cross - 🧠ANSWER ✔✔A cross between individuals that have 4
alleles for 2 genes
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
1
STATEMENT. ALL RIGHTS RESERVED
, Sex-linked characterisitics - 🧠ANSWER ✔✔genes on the sex
chromosomes
Females - 🧠ANSWER ✔✔have 25% chance of having a characteristic
because they can be carriers without having the characteristic
Males - 🧠ANSWER ✔✔have 50% chance of having a characteristic
DNA - 🧠ANSWER ✔✔-deoxyribonucleic acid
-double stranded
-Sugar: deoxyribose
-Phosphate
-Nitrogenous base:
1. Adenine
2. Thymine
3. Cytosine
4. Guanine
RNA - 🧠ANSWER ✔✔-ribonucleic acid
-single stranded
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
2
STATEMENT. ALL RIGHTS RESERVED
