DepEd MELC reviewer for Grade 8 Science, Quarter 4. Master the concepts, tables, and common-mistake warnings below.
1
Mendelian Genetics
Traits are passed by genes. Dominant alleles (capital) mask recessive (lowercase). Use a Punnett square to predict offspring.
Tt × Tt → 1 TT : 2 Tt : 1 tt (3 tall : 1 short)
⚠️ Common Mistake
An organism showing a recessive trait must be homozygous recessive (tt). A dominant trait can be TT or Tt.
2
Biodiversity
Biodiversity is the variety of life. The Philippines is a megadiverse country with many endemic species.
3
Classification
Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species
4
Punnett Square Example
Cross Tt × tt (T = tall, dominant):
Offspring: 2 Tt (tall) : 2 tt (short) → 50% tall, 50% short
💡 Exam Hack
Each parent contributes ONE allele to each offspring.
📌 Quick Recap — Master These
Before your test, make sure you can confidently do each of the following:
- Explain and apply Mendelian Genetics.
- Explain and apply Biodiversity.
- Explain and apply Classification.
- Explain and apply Punnett Square Example.
Re-read any section above where you hesitate, then try the worked example again without looking.