Docsity
Log inSign up
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search Store documents

The best documents sold by students who completed their studies

Search through all study resources
Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

From our blog

Exams and Study
Go to the blog

Punnett Squares and Genetic Traits: Understanding Genotypic and Phenotypic Ratios, Study notes of Genetics

University of Advancing TechnologyGenetics

An explanation of punnett squares, a tool used to predict the genotypic and phenotypic ratios of offspring based on the genotypes of the parents. Examples and practice problems to help students understand the concepts of dominant and recessive traits, genotypic and phenotypic ratios, and how to construct a punnett square. This resource is ideal for students studying genetics, biology, or related fields.

Typology: Study notes

2021/2022

Uploaded on 09/27/2022

hardcover
hardcover 🇺🇸

4.7

(7)

259 documents

1 / 4

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Name:&__________________________________________________________________&
&
Single'Trait'Punnett'Squares'
&
Background:'
'
Punnett&squares&shoes&the&genes&(represented&by&letter&–&capital&(dominant)&or&lower&case&(recessive)&
that&could&be&present&in&the&parents’&gametes.&The&possibilities&for&the&male&and&female&gametes&are&then&
placed&along&the&side&and&the&top&of&the&square.&Then&by&looking&at&possible&gene&combinations&in&the&
zygote,&you&can&predict&what&is&expected&in&the&offspring&by&calculating&the&genotypic&and&phenotypic'
rations.&Remember&that&the&genotype&is&the&combination&of&the&alleles&and&the&phenotype&is&the&actual&
physical&trait&that&is&expressed.&&
&
&
Example:'
&
A&homozygous&green&pea&plant&(GG)&is&crossed&with&a&heterozygous&green&pea&plant&(Gg).&&
&
&
&
&
&&&&&&&Genotypic'ratio:&2&GG&:&2&Gg&:&0&gg&
&
&
&&&&&&'Phenotypic'ratio:&4&green&pea&plants&:&0&other&color&
&
&
&
&
&
Practice'Problems:'
'
1.&Tall&(T)&is&dominant&to&short&(t)&in&pea&plants.&What&are&the&genotypic&and&phenotypic&ratios&of&the&
offspring&with&parents&that&are&both&heterozygous&tall&(Tt)?&
&
Tall&(dominant)&=&& & & & &
&
Short&(recessive)&=&&&&&&&&&&&&
&
&
&
&
genotypic&ratio:&_____________________________&
&
&
&&&&&&&phenotypic&ratio:&____________________________&
&
&
&
&
&
G&
G&
G&
g&
GG&
GG
Gg&
Gg&
pf3
pf4

Partial preview of the text

Download Punnett Squares and Genetic Traits: Understanding Genotypic and Phenotypic Ratios and more Study notes Genetics in PDF only on Docsity!

Name: __________________________________________________________________ Single Trait Punnett Squares Background: Punnett squares shoes the genes (represented by letter – capital ( dominant ) or lower case ( recessive ) that could be present in the parents’ gametes. The possibilities for the male and female gametes are then placed along the side and the top of the square. Then by looking at possible gene combinations in the zygote, you can predict what is expected in the offspring by calculating the genotypic and phenotypic rations. Remember that the genotype is the combination of the alleles and the phenotype is the actual physical trait that is expressed. Example: A homozygous green pea plant (GG) is crossed with a heterozygous green pea plant (Gg). Genotypic ratio: 2 GG : 2 Gg : 0 gg Phenotypic ratio: 4 green pea plants : 0 other color Practice Problems:

  1. Tall (T) is dominant to short (t) in pea plants. What are the genotypic and phenotypic ratios of the offspring with parents that are both heterozygous tall (Tt)? Tall (dominant) = Short (recessive) = genotypic ratio: _____________________________ phenotypic ratio: ____________________________

G G

G

g

GG GG

Gg Gg

  1. Cross a homozygous tall plant (TT) with a short plant (tt). What are the genotypic and phenotypic ratios of the offspring? Parent 1 genotype: ______________________ Parent 2 genotype: ______________________ Gametes of parent 1: ____________________ Gametes of parent 2: ____________________ genotypic ratio: _____________________________________ phenotypic ratio: ____________________________________
  2. When another tall plant is crossed with a short plant, some of the offspring are short. a. What must be the genotypes of the parents? ____________________________________________ b. What are the genotypes of the offspring? ________________________________________________ c. What is the phenotypic ratio in the offspring? ___________________________________________ d. Show the punnett square below.
  3. Yellow pod color (Y) is dominant to green pod color (y) in pea plants. Cross a heterozygous plant (Yy) with a green plant (yy). What are the genotypic and phenotypic ratios of the offspring? genotypic ratio: _____________________________________ phenotypic ratio: ____________________________________
  1. In mice, black hair color (B) is dominant over brown hair color (b). Cross a homozygous black mouse with a heterzygous black mouse and determine the genotypic and phenotypic ratios of their offspring. Genotypic ratio: _____________________________________ Phenotypic ratio: ____________________________________
  2. Two black mice are mated several times. Out of 100 offspring, 25 of them have brown hair. What are the probable genotypes of the parents? ________________________________ Show the cross to prove it.