Genetics Practice Problems
1. For each genotype, indicate whether it is heterozygous (A) or homozygous (B).
AA Bb Cc Dd
Ee ff GG HH
Jj kk Ll Mm
nn OO Pp
2. For each of the genotypes below, determine the phenotype.
A) Purple flowers are dominant to white flowers
QQ _________
Qq _
qq _
B) Brown eyes are dominant to blue eyes
BB _ Bb _ bb _
C) Round seeds are dominant to wrinkled
RR _
Rr _
rr __
D) Bobtails are recessive (long tails dominant)
TT _ Tt _ tt ______
3. For each phenotype, list the genotypes. (Use the letter of the dominant trait)
Straight hair is dominant to curly. straight straight curly
Pointed heads are dominant to round heads. pointed
pointed
round
4. Set up the Punnett square for each of the crosses listed below. The trait being studied is round seeds (dominant) and wrinkled seeds (recessive).
A) Rr x rr
B) Rr x Rr
C) RR x Rr
What percentage of the offspring will be round?
%
What percentage of the offspring will be round?
%
What percentage of the offspring will be round?
%

5. Practice with crosses and Punnett squares. Show all work!
A) A TT (tall) plant is crossed with a tt (short plant). What percentage of the
offspring will be tall?
B) A Tt plant is
crossed with a Tt plant. What percentage of the offspring will be short?
C) A heterozygous round seeded plant (Rr) is crossed with a homozygous round seeded plant (RR). What percentage of the offspring will be homozygous (RR)?
D) Ahomozygousroundseededplant is crossed with a homozygous wrinkled seeded plant. What are the genotypes of the parents? What percentage of the offspring
will also be homozygous?
E) In pea plants yellow flowers
are dominant to white flowers.
If two white flowered plants are crossed, what percentage of their offspring will be white flowered?
F) A white flowered plant is crossed with a plant that is heterozygous for the trait. What percentage of the offspring will have yellow flowers?
G) Two plants, both heterozygous for
the gene that controls flower color
are crossed. What percentage of
their offspring will have yellow flowers? What percentage will have white flowers?
H) In guinea pigs, the allele for long hair is dominant.
What genotype would a heterozygous longhaired guinea pig have?
What genotype would a pure breeding longhaired guinea pig have? What genotype would a shorthaired guinea pig have?
I) Show the cross for a pure breeding longhaired guinea pig and a shorthaired guinea pig. What percentage of the offspring will have long hair?
J) Show the cross for two heterozygous guinea pigs. What percentage of the offspring will have long hair?
What percentage of the offspring will have short hair?

Question

26-03-2020
Biology

contestada

Genetics Practice Problems
1. For each genotype, indicate whether it is heterozygous (A) or homozygous (B).
AA Bb Cc Dd
Ee ff GG HH
Jj kk Ll Mm
nn OO Pp
2. For each of the genotypes below, determine the phenotype.
A) Purple flowers are dominant to white flowers
QQ _________
Qq _
qq _
B) Brown eyes are dominant to blue eyes
BB _ Bb _ bb _
C) Round seeds are dominant to wrinkled
RR _
Rr _
rr __
D) Bobtails are recessive (long tails dominant)
TT _ Tt _ tt ______
3. For each phenotype, list the genotypes. (Use the letter of the dominant trait)
Straight hair is dominant to curly. straight straight curly
Pointed heads are dominant to round heads. pointed
pointed
round
4. Set up the Punnett square for each of the crosses listed below. The trait being studied is round seeds (dominant) and wrinkled seeds (recessive).
A) Rr x rr
B) Rr x Rr
C) RR x Rr
What percentage of the offspring will be round?
%
What percentage of the offspring will be round?
%
What percentage of the offspring will be round?
%

5. Practice with crosses and Punnett squares. Show all work!
A) A TT (tall) plant is crossed with a tt (short plant). What percentage of the
offspring will be tall?
B) A Tt plant is
crossed with a Tt plant. What percentage of the offspring will be short?
C) A heterozygous round seeded plant (Rr) is crossed with a homozygous round seeded plant (RR). What percentage of the offspring will be homozygous (RR)?
D) Ahomozygousroundseededplant is crossed with a homozygous wrinkled seeded plant. What are the genotypes of the parents? What percentage of the offspring
will also be homozygous?
E) In pea plants yellow flowers
are dominant to white flowers.
If two white flowered plants are crossed, what percentage of their offspring will be white flowered?
F) A white flowered plant is crossed with a plant that is heterozygous for the trait. What percentage of the offspring will have yellow flowers?
G) Two plants, both heterozygous for
the gene that controls flower color
are crossed. What percentage of
their offspring will have yellow flowers? What percentage will have white flowers?
H) In guinea pigs, the allele for long hair is dominant.
What genotype would a heterozygous longhaired guinea pig have?
What genotype would a pure breeding longhaired guinea pig have? What genotype would a shorthaired guinea pig have?
I) Show the cross for a pure breeding longhaired guinea pig and a shorthaired guinea pig. What percentage of the offspring will have long hair?
J) Show the cross for two heterozygous guinea pigs. What percentage of the offspring will have long hair?
What percentage of the offspring will have short hair?

Respuesta :

Otras preguntas

You are attempting to install Windows Server 2016 on a SCSI based disk, but the installation program does not find the disk. What is the most likely cause:_____

Physical distractions as barriers to communication are usually harder to prevent in a speaking or listening situation because the surroundings cannot be control

When a continental plate collides with an oceanic plate, the oceanic plate is forced down towards the asthenosphere in a process known as___________.

Identify three common purposes for people to create a political constitution. to define a specific region as a political unit to protect basic citizen rights an

The French club sold rose bouquets and chocolate hearts for Valentine’s Day. The roses sold for $5 and the hearts sold for $3. The number of bouquets sold was 1

In some interpersonal communication contexts, the relational dimensions of a message may be more important than the content of a message. True / False.

We have a file that has a name in it, but the name is written one character per line. We need to write this name to the screen. What is wrong with the following

what type of molecule is shown in the leaf

A solution was made by dissolving 25 g of potassium malonate K2C3H2O4 (MM=180.2 g/mol) in water. The total volume of that solution is 455 ml. a) calculate the p

A nurse is caring for a client with sleep apnea. Which nursing intervention would be most appropriate to prevent hypoxia in the client?

josinclair73 josinclair73 · Answer 1 · 2020-04-04T04:11:34+02:00

Answers and explanations:

1. For each genotype, indicate whether it is heterozygous (A) or homozygous (B).

Homozygous (A) and heterozygous (B) refers to the presence of two equal or different alleles for the same trait, respectively.

AA (A).
Bb (B).
Cc (B).
Dd (B).
Ee (B).
ff (B).
GG (A).
HH (A).
Jj (B).
kk (A).
Ll (B).
Mm (B).
nn (A).
OO (A).
Pp (B).

2. For each of the genotypes below, determine the phenotype.

A) Purple flowers are dominant to white flowers

QQ Purple flowers.
Qq Purple flowers.
qq White flowers.

B) Brown eyes are dominant to blue eyes

BB Brown eyes.
Bb Brown eyes.
bb Blue eyes.

C) Round seeds are dominant to wrinkled

RR Round seeds.
Rr Round seeds.
rr Wrinled seeds.

D) Bobtails are recessive (long tails dominant)

TT Longtails.

Tt Longtails.

tt Bobtails.

3. For each phenotype, list the genotypes. (Use the letter of the dominant trait)

Straight hair is dominant to curly.

SS Straight.

Ss Straight.

ss Curly.

Pointed heads are dominant to round heads.

PP Pointed .

Pp Pointed .

pp Round.

4. Set up the Punnett square for each of the crosses listed below. The trait being studied is round seeds (dominant) and wrinkled seeds (recessive).

A) Rr x rr

Alelles R r

r Rr rr

Results of the crossing

RR (Round seed homozygous) None.
Rr (Round seed heterozygous) 50%.
rr (Wrinkled seeds homozygous) 50%.

What percentage of the offspring will be round?

- 50%

B) Rr x Rr

Alelles R r

R RR Rr

r Rr rr

Results of the crossing

RR (Round seed homozygous) 25%.
Rr (Round seed heterozygous) 50%.
rr (Wrinkled seeds homozygous) 25%.

What percentage of the offspring will be round?

- 75 %

C) RR x Rr

Alelles R R

R RR RR

r Rr Rr

Results of the crossing

RR (Round seed homozygous) 50%.
Rr (Round seed heterozygous) 50%.
rr (Wrinkled seeds homozygous) None.

What percentage of the offspring will be round?

- 100%

5. Punnett squares.

A) A TT (tall) plant is crossed with a tt (short plant). What percentage of the offspring will be tall?

The result of the cross between two pure lines (TT and tt) is always a 100% heterozygous offspring (Tt), with the phenotype of the dominant trait.

Alelles T T

t Tt Tt

100% of the offspring will be tall.

B) Tt X Tt

Alelles T t

T TT Tt

t Tt tt

Results of the crossing

TT (Tall plants homozygous) 25%.
Tt (Tall plants heterozygous) 50%.
tt (Short plants homozygous) 25%.

25% of the offspring will be short.

C) RR X Rr

Alelles R R

R RR RR

r Rr Rr

Results of the crossing

RR (Round seed homozygous) 50%.
Rr (Round seed heterozygous) 50%.
rr (Wrinkled seeds homozygous) None.

50% of the offspring will be homozygous (RR).

D) RR X rr

Parent Genotypes: Homozygous round seeded RR and homozygous wrinkled seed rr.

Alelles R R

r Rr Rr

There are no homozygous offspring at this crossing.

E) White/Yellow flowered (pea) plants.

Q for yellow flowers.

q for white flowers.

Parent Genotypes: Pea plants white flowers qq.

Alelles q q

q qq qq

100% of the offspring will be white flowered (qq).

F) White/Yellow flowered plants.

- Q for yellow flowers.

- q for white flowers.

Parent Genotypes: White flowered plant qq and yellow flowered plant (heterozygous) Qq.

Alelles Q q

q Qq qq

Results of the crossing

QQ (Yellow flowered homozygous) none
Qq (Yellow flowered heterozygous) 50%.

qq (White flowered homozygous) 50%.

50% of the offspring will be yellow flowered (Qq).

G) Qq X Qq

Parent Genotypes: Yellow flowered plant Qq (both heterozygous).

Alelles Q q

Q QQ Qq

q Qq qq

Results of the crossing

QQ (Yellow flowered homozygous) 25%.
Qq (Yellow flowered heterozygous) 50%.
qq (White flowered homozygous) 25%.

75% of the offspring will have yellow flowers (QQ and Qq).

25% of the offspring will have white flowers (qq).

H) Guinea pigs, the allele for long hair is dominant.

C for longhaired guinea pig.

c for shorthaired guinea pig.

Heterozygous longhaired guinea pig have Cc genotype.
Pure breeding longhaired guinea pig have CC genotype.
Shorthaired guinea pig have cc genotype.

I) Guinea pigs CC X cc

Parent Genotypes:

Pure breeding longhaired guinea pig have CC genotype.
Shorthaired guinea pig have cc genotype.

CC X cc

Alelles C C

c Cc Cc

100% of the offspring will have long hair (Cc)

J) Guinea pigs Cc X Cc

Alelles C c

C CC Cc

c Cc cc

Results of the crossing

CC (Long hair homozygous) 25%.
Qq (Long hair heterozygous) 50%.
qq (Short hair homozygous) 25%.