Genetics Review Packet (the 4 pages of punnett squares)

1. Dominant - The gene that always shows, usually a capital letter
2. Recessive - The gene that is present only when the dominant gene is not present, usually a lower case letter
3. 1/4 (triangle) 1:3 (circle) 75% (square)
4. a. gene b. homozygous c. punnett square d. genotype e. phenotype f. ratio g. probability
5. a. heterozygous b. heterozygous c. homozygous dominant d. heterozygous e. homozygous recessive f. homozygous recessive g. homozygous dominant h. heterozygous
6. 25% - BB 50% - Bb 25% - bb
7. 0% - BB; 50% - Bb; 50% - bb
8. 1/4 BbEe (Black hair/ brown eyes); 1/4 Bbee (Black hair/ blue eyes); 1/4 bbEe (blonde hair/brown eyes); bbee (blonde hair/blue eyes)
9. Parent 1 - rr and Parent 2 - Rr; (rr x Rr) 50% White, 50% Pink
10. Males (XY); Females (XX)
11. Cross XY and XX
12. a. 100% Type O; b. 100% Type AB; c. 50% Type A, 50% Type B
13. a. 2/2 girls with normal vision, 1/2 normal boys, 1/2 boys colorblind; b. 2/2 girls are normal, 2/2 boys are colorblind; c. 2/2 girls are normal, 2/2 boys are normal

Genetics Study Guide Answer

This was today's hand out:

C - Level
1. C. AABbcc will look the same as AaBBcc 
2. Meiosis - makes sex cells, 4 genetically different cells; Mitosis – makes every other cell, 2 genetically identical cells 
3. Tt x Tt = 75% will look like T, 25% will look like t
4. Incomplete Dominance (3rd phenotype appears)
5. XHXh with XHY
a. Daughters with hemophilia – 0% 
b. Sons with hemophilia – 50% 
6. Two organisms may share the same phenotype, but have differing genotype. 
7. Bb x Bb (75% Black, 25% Brown fur)
8. To make genetically different cells
9. Sex cells are also known as gametes. Since they only have 1 set of chromosomes, they are called haploid. Cells with 2 sets of chromosomes are called diploid.
10. 2 brothers!

B – Level
1. Incomplete dominance 
a. RR – red, rr – white, Rr – pink. 
b. rr x Rr = 50% white, 50% pink
2. Key: BB – blue, bb – white, Bb – blue AND white. Bb x Bb = 25% Blue, 25% white, 50% blue and white.
3. ii x IAIB = 50% Type A, 50% Type B
4. (check with Mrs. Sohn in class)
5. XBXB with XbY
a. 0% sons will be colorblind
b. 0% of daughters will be colorblind
6. Key: D – Dark, d – blonde
a. Dd
b. dd
c. 50%

A – Level
1. Dihybrid Cross
a. BbEe
b. bbee
c. ¼
d. ¼ 
2. Males are more likely to inherit sex-linked traits because they only have one X. If there is something wrong with that X, they will always show the trait. They do not have another X to “make up” for that other X.
3. ii x ii; IAi x IAi, IBi x IBi