Genetic Disorder
Class 11 · Biotechnology
4 ideas in Class 11 Biotechnology, explained in plain words, with games and quizzes to practise.
Chromosome Shape Changes
Part of: Broken Chromosomes
Deletion shortens as in retinoblastoma on chromosome 13, duplication lengthens as in Charcot-Marie-Tooth on 17, inversion flips a segment 180 degrees as in RCAD on 17, Burkitt lymphoma swaps 8 with 14 reciprocally while Robertsonian drops the count, and crops stack sets from triploid banana to octoploid strawberry.
Why it matters. Shape change plus example pair answers sorting questions.
Key words
- Deletion
- : Lost chromosome segment.
- Duplication
- : Repeated chromosome segment.
- Inversion
- : Reversed chromosome segment.
- Translocation
- : Segment moved between chromosomes.
- Polyploidy
- : Multiplied whole chromosome set.
Try it in two minutes
- Shorten or lengthen.
- Flip or swap.
- Stack whole sets.
Try at home. Match each disease to its change type.
Three Number Syndromes
Part of: Broken Chromosomes
Down adds 21 to 47 with 1 in 800 births and 85 percent from mothers over 35 rising from age 9 to 60 years, Klinefelter adds X to 47 XXY in 1 in 1000 males with one Barr body, and Turner loses X to 45 with no Barr body in 1 in 2500 girls.
Why it matters. Count plus clue plus test answers syndrome questions.
Key words
- Trisomy
- : Three copies of a chromosome.
- Monosomy
- : Single copy of a chromosome.
- Karyotype
- : Ordered chromosome picture.
- Barr body
- : Inactive X signal.
- Nondisjunction
- : Failed chromosome separation.
Try it in two minutes
- Count 45, 46, 47.
- Check Barr body.
- Note maternal age.
Try at home. Write each karyotype from memory.
One-Gene Rules
Part of: Inheritance Patterns
Sickle s/s on chromosome 11 needs two copies while S/s carriers stay healthy, cystic fibrosis hides over 200 changes in one gene, achondroplasia D/d survives while D/D often proves fatal, haemophilia A and B break factors VIII and IX, and X-linked fathers give carrier daughters while affected mothers pass to half the children.
Why it matters. Copy counting plus parent rules solve pedigree questions.
Key words
- Carrier
- : Healthy single-copy holder.
- Homozygous
- : Two identical copies.
- Heterozygous
- : Two different copies.
- X-linked
- : Gene carried on X.
- Pedigree
- : Family inheritance tree.
Try it in two minutes
- Count faulty copies.
- Trace X path.
- Halve carrier crosses.
Try at home. Draw S/s cross with four boxes.
Many Genes Plus Energy
Part of: Inheritance Patterns
Type 1 diabetes kills beta cells in 10 percent of cases while type 2 resists insulin in 90 percent, vessel readings stage from under 120 over 80 to 140 over 90, plaque narrows heart arteries into ischemia, and mitochondrial genes flow from mothers only with severity set by the normal-to-faulty ratio.
Why it matters. Shares plus stages plus mother-only rule answer mixed questions.
Key words
- Polygenic
- : Many genes together.
- Hyperglycemia
- : High sugar level.
- Hypertension
- : High vessel pressure.
- Atherosclerosis
- : Fatty artery build-up.
- Ischemia
- : Low supply to tissue.
Try it in two minutes
- Split 10 and 90.
- Stage the reading.
- Follow the mother.
Try at home. Stage three sample readings.
What your child will practise
- Chromosome Shape Changes: Ocean Puzzle (Clue Puzzle)
- Chromosome Shape Changes: Ocean Quick Fire (Quick Fire)
- Many Genes Plus Energy: Jungle Puzzle (Clue Puzzle)
- One-Gene Rules: Space Quest (Flip and Match)
- Three Number Syndromes: Desert Quick Fire (Quick Fire)
- Quiz: Chromosome Shape Changes (8 questions)
- Quiz: Many Genes Plus Energy (8 questions)
- Quiz: One-Gene Rules (8 questions)
- Quiz: Three Number Syndromes (8 questions)