Question

pedigree #1:

1. how many people are there in the family?
2. how many chromosomal males are there in the family?
3. how many chromosomal females are there in the family?
4. how many generations are there?
5. how many people in the whole family have the disease?
6. what is the sex of the parent who has the disease?
7. how many people are in the f₁ generation?
8. how many people in the f₁ generation have the disease?
9. what is the sex of the person in the f₁ generation who has the disease?
10. how many people are there in the f₂ generation?
11. how many people in the f₂ generation have the disease?

Explanation:

1. How many people are there in the family?

Step1: Count each individual in the pedigree.

• Top generation (P generation): 2 people (1 square, 1 circle with disease).
• F₁ generation: 4 people (1 square with disease, 2 circles, 1 square) + 2 people (1 square, 1 circle) = 6? Wait, no, let's re - count. Wait, the top generation (parents) has 2. Then their children (F₁): let's see the first branch: 1 square (affected), 2 circles, 1 square? Wait, no, the first pair (top) has children: the first row below top: 1 square (affected), 2 circles, 1 square? Wait, no, looking at the pedigree:

Top (P): 2 (square, circle with disease)

F₁: Let's count the children of P: 1 square (affected), 2 circles, 1 square? Wait, no, the first row below P: the first family (square with disease and circle) has children, but the F₁ is the children of P. Wait, the P has 4 children? Wait, the pedigree:

• P generation: 2 (square, circle - filled)
• F₁ generation: 4 (from P: square - filled, circle, square, square) + 2 (the other couple? No, wait, the other couple is in F₁? Wait, no, the first couple (P) has children: the first row below P: 1 square - filled, 2 circles, 1 square? Wait, no, the diagram:

Top: square (white) and circle (filled) → 2.

Then their children (F₁): 1 square (filled), 2 circles (white), 1 square (white), and then another couple (square and circle, white) → but that couple is also F₁? Wait, no, the total people:

Let's list all:

1. P: white square
2. P: filled circle
3. F₁: filled square
4. F₁: white circle
5. F₁: white square
6. F₁: white square
7. F₁: white circle (the other couple's female)
8. F₁: white square (the other couple's male)

Then the children of filled square and white circle (F₂):

1. filled circle
2. filled circle
3. white square

Children of white square and white circle (F₂):

1. white square
2. white circle

Wait, that's 13? Wait, no, let's count again carefully:

• P generation: 2 (1,2)
• F₁ generation: 4 (3 - 6: 3 - filled square, 4 - white circle, 5 - white square, 6 - white square) + 2 (7 - white circle, 8 - white square) → total F₁: 6
• F₂ generation: 3 (9 - filled circle, 10 - filled circle, 11 - white square) + 2 (12 - white square, 13 - white circle) → total F₂: 5

Total: 2+6 + 5=13? Wait, no, maybe I made a mistake. Let's count each node:

1. Top left: white square (P)
2. Top right: filled circle (P)
3. Middle left: filled square (F₁)
4. Middle: white circle (F₁)
5. Middle right: white square (F₁)
6. Far right (F₁): white square (F₁)
7. Below 6: white circle (F₁, the other couple's female)
8. Below 5: white square (F₁, the other couple's male)
9. Below 3 and 4: filled circle (F₂)
10. Below 3 and 4: filled circle (F₂)
11. Below 3 and 4: white square (F₂)
12. Below 7 and 8: white square (F₂)
13. Below 7 and 8: white circle (F₂)

Wait, that's 13. But maybe my initial count was wrong. Wait, the correct way:

Count all the symbols:

• White square: 1 (P) + 3 (F₁) + 2 (F₂) + 1 (F₂) → 1+3 + 3=7? No, let's count each symbol:

Filled circle: 1 (P) + 2 (F₂) = 3

Filled square: 1 (F₁)

White square: 1 (P) + 3 (F₁) + 2 (F₂) = 6

White circle: 3 (F₁) + 2 (F₂) = 5

Total: 3 (filled circle) + 1 (filled square) + 6 (white square) + 5 (white circle)=15? No, I'm confused. Wait, let's use a better approach:

Each symbol is a person:

1. Top white square
2. Top filled circle
3. F₁ filled square
4. F₁ white circle
5. F₁ white square
6. F₁ white square
7. F₁ white circle (the other F₁ female)
8. F₁ white square (the other F₁ male)
9. F₂ filled circle (child of 3 and 4)
10. F₂ filled circle (child of 3 and 4)
11. F₂ white square (child of 3 and 4)
12. F₂ white square (ch…

Step1: Identify chromosomal males (squares).

White squares: 1 (P) + 3 (F₁: 5,6,8) + 2 (F₂: 11,12) = 1 + 3+2 = 6

Filled square: 1 (F₁: 3)

Total squares (males): 6 + 1=7

Step2: Count.

So chromosomal males: 7 (1 P, 4 F₁, 2 F₂)

Step1: Total people - chromosomal males.

Total people:13, chromosomal males:7, so 13 - 7 = 6

Or count circles:

Filled circles:1 (P) + 2 (F₂:9,10) = 3

White circles:3 (F₁:4,7) + 1 (F₂:13) = 4? Wait, no, 4 (F₁:4,7, and two in F₁? Wait, F₁ circles: 4 (4,7, and two others? No, earlier count:

Filled circles: P (2), F₂ (9,10) → 1 + 2 = 3

White circles: F₁ (4,7) + F₂ (13) + F₁ (another? Wait, F₁ has 4 (3 - 6: 4 is white circle, 7 is white circle, and two others? No, F₁: 3 - filled square, 4 - white circle, 5 - white square, 6 - white square, 7 - white circle, 8 - white square. So white circles in F₁: 4,7 → 2. F₂ white circles:13 → 1. Filled circles:2 (P) + 2 (F₂) → 3. Wait, 3 + (2 + 1)=6. Yes, 3 filled (females) + 3 white (females)=6.

Answer:

13

2. How many chromosomal males are there in the family?