Read A Pedigree
Use a genetics model to read a pedigree with clear limits.
- DNA/RNA base pairing: Sequence and codon tasks depend on reading bases in order.
- Read a genetics model: Pedigrees, karyotypes, and charts are models that need a key.
Prerequisites are inferred: pending teacher review.
Re-learn the skill with worked practice and clear examples.
Use a genetics model to read a pedigree with clear limits.
Use the genetics figure/table. Which interpretation is most careful?
Reviewed- A.Leave out the people whose status is unknown
- B.Use the key/chart result and state only what it supports
- C.Guess the pattern from the shapes without reading the key
- D.Call every marked person in the chart a disease carrier
Show the worked solution ▾
Answer: B. Use the key/chart result and state only what it supports
- Step 1: Use the model: The figure/table provides the needed key.
- Step 2: Avoid overclaiming: Genetic evidence often shows risk or pattern, not certainty alone.
Why it's right: The careful answer uses the model and respects limits.
- A: Unknown status is a limitation to state, not data to drop.
- C: The key says what each shape means, so guessing skips the evidence.
- D: A marked symbol can mean carrier, affected, or tested, depending on the key.
Aligned to Biotechnology Research and Experiments · reading level ~grade 9
In a standard pedigree, squares stand for males, circles for females, and a filled-in symbol means the person has the condition. What does a filled-in circle stand for?
Reviewed- A.A female who does not have the condition
- B.A male who has the condition
- C.A female who has the condition
- D.A female carrier who shows no signs herself
Show the worked solution ▾
Answer: C. A female who has the condition
- Step 1: Read the shape: A circle stands for a female.
- Step 2: Read the fill: A filled-in symbol means the person has the condition.
Why it's right: The circle gives the sex and the fill gives the status, so a filled-in circle is a female who has the condition.
- A: An unfilled circle would mean a female without the condition.
- B: A male would be drawn as a square, not a circle.
- D: Carrier status is not shown by a plain filled symbol; a filled symbol means the person is affected.
Aligned to Biotechnology Research and Experiments · reading level ~grade 9
- In Unit 2.2 to 2.3 Genetic Risk, this skill turns class evidence into a result another person can check.
Fill these in as you work through the lesson.
- Allele (version of a gene):
- Genotype (allele combination):
- Phenotype (observable trait):
- Carrier (has allele but may not show trait):
Read the genetic first, compare it to the key or chart, and separate risk from a confirmed .
- What does the model key say?
- What pattern or DNA change is shown?
- Does this show risk, carrier status, or diagnosis?
Use the provided model to practice read a pedigree and write one cautious interpretation.