Question

1. the following dna gene creates the protein for long ears. use a codon chart to write the amino acids in this protein chain

• the dna: cag tcg cgt = this mrna: __________ = these three amino acids: __ __ ____
• to get short ears instead of long, the second amino acid needs to be glycine. write a dna gene sequence for short ears ____________________

1. we learned that dominant always overpowers recessive when there is one of each gene together. this usually results in more dominant traits in society. look at the traits of your dog and those of your mate. did your dogs have more dominant traits? give me numbers to support your answer.
2. what is the name of the process that makes egg and sperm? ____________
3. what two chromosomes make a male and what two make a female?

male = ______ female = ______

1. which parent determines the gender of an offspring and why is this?
2. a couple has five girls. they are having a sixth child. what are the chances of having another girl? do a punnett square to help explain your answer.
3. incomplete - dominant traits are different than complete dominance. explain how incomplete dominant traits work and how a hybrid offspring (one of each) would turn out. use the dogs coat color as an example in your explanation.
4. dihybrid cross - take the traits of ear shape and length. what are the odds that an offspring would have long and droopy ears if both parents were heterozygous for both traits? do the dihybrid cross and highlight the boxes with the trait mentioned above. give genotype and phenotype ratios.

Explanation:

Step1: Transcribe DNA to mRNA

DNA: GAG TCG CGT → mRNA: $\text{CUC AGC GCA}$ (A↔U, T↔A, C↔G, G↔C)

Step2: Match mRNA to amino acids

CUC = Leucine; AGC = Serine; GCA = Alanine

Step3: Find Glycine codons & reverse

Glycine mRNA codons: GGU, GGC, GGA, GGG → DNA complements: CCA, CCG, CCT, CCC. Replace 2nd DNA codon (TCG) with one (e.g., CCG)

Step4: Identify gamete formation process

Gametes (egg/sperm) form via meiosis

Step5: List sex chromosome pairs

Male: XY; Female: XX

Step6: Explain gender-determining parent

Father has XY, gives X/Y; mother has XX, only gives X. Offspring sex depends on father's gamete.

Step7: Calculate 6th child gender odds

Punnett square: Father (X,Y) × Mother (X,X) → 2/4 female, 2/4 male. Probability = $\frac{1}{2}$

Step8: Explain incomplete dominance

Neither trait is dominant; hybrid shows blended phenotype. For dog coat: black (BB) × white (WW) → gray (BW) hybrid.

Step9: Dihybrid cross setup

Let long ears (L), short (l); droopy (D), erect (d). Parents: LlDd × LlDd. Gametes: LD, Ld, lD, ld.

Step10: Fill dihybrid Punnett square

	LD	Ld	lD	ld
Ld	LLDd	LLdd	LlDd	Lldd
lD	LlDD	LlDd	llDD	llDd
ld	LlDd	Lldd	llDd	lldd

Long droopy (L_D_): 9 boxes

Step11: Calculate dihybrid ratios

Genotype ratio: 1:2:1:2:4:2:1:2:1; Phenotype ratio: 9(long droopy):3(long erect):3(short droopy):1(short erect)

Step12: Address trait count question

(Note: This requires personal dog trait data; example: My dog has 4 dominant traits (curly fur, brown eyes, floppy ears, large size), mate's dog has 3 dominant traits. Total dominant traits: 7 out of 8 total traits, so more dominant traits are present.)

Answer:

4.

• mRNA: $\text{CUC AGC GCA}$
• Amino acids: Leucine, Serine, Alanine
• Short ears DNA sequence: $\text{GAG CCG CGT}$ (one valid option)

1. (Example answer) My dog has 4 dominant traits (curly fur, brown eyes, floppy ears, large size), my mate's dog has 3 dominant traits (short fur, brown eyes, pointed ears, large size). Total dominant traits are 7 out of 8 total tracked traits, so the dogs have more dominant traits.
2. Meiosis

7.

• Male = XY
• Female = XX

1. The father (male parent) determines the gender of the offspring. The mother can only pass an X chromosome, while the father can pass either an X or a Y chromosome. If the father passes an X, the offspring is female (XX); if he passes a Y, the offspring is male (XY).
2. The chance of having another girl is 50% ($\frac{1}{2}$).
3. In incomplete dominance, neither allele is fully dominant over the other. When an organism has one copy of each allele (hybrid), its phenotype is a blend of the two parent phenotypes. For example, if a dog with a black coat (genotype BB) breeds with a dog with a white coat (genotype WW), the hybrid offspring (genotype BW) will have a gray coat, which is a mix of the black and white parent traits.

11.

• Punnett Square (filled in above)
• Genotype Ratio: 1 LLDD : 2 LLDd : 1 LLdd : 2 LlDD : 4 LlDd : 2 Lldd : 1 llDD : 2 llDd : 1 lldd
• Phenotype Ratio: 9 long droopy ears : 3 long erect ears : 3 short droopy ears : 1 short erect ears
• Odds of long and droopy ears: $\frac{9}{16}$