Biology Tutorials DNA and Genetics Part 2

• ​Spiral shape = double helix

• Two-sided​

• Made of nucleotides

  • ​Adenine, Thymine, Cytosine, and Guanine

​​DNA Structure

​

• ​DNA = chemical instructions for making proteins

  • Proteins determine your traits!​

​​DNA Function

​

Match

Match the following base pairs.

• A

• G

• T

T

C

A

• T

• C

• A

Multiple Choice

According to Chargaff's rule, there are equal numbers of certain nitrogenous bases in DNA due to base pairing. So if we were to inspect a molecule of DNA and 20% of it was composed of Cytosine, what percentage would be composed of Adenine?

• 20%

• 30%

• 40%

• 25%

• ​specific base pairs in a specific order

• code that tells proteins what traits to give you

​Genes

​

= Height Gene

​

​Example

​

ATCG/TAGC = Tall

Multiple Choice

This is a picture of ?

• Gene

• Chromosome

• Medicine

• Genotype

Multiple Choice

________ are changes in genetic material. 

• Genes

• Mutations

• Variations

• Biology

Creating and Solving monohybrid Punnett squares

Please watch the directions twice and take notes- Questions to follow

Monohybrid punnet squares

Multiple Choice

A Punnett square shows you all the ways in which _____ can combine.

• Genes

• phenotypes

• Alleles

• dogs

Multiple Choice

The dominant trait is

• yellow pea seeds

• green pea seeds

• there is no dominant seed

• Jolly green giant

Multiple Choice

This type of allele masks the recessive allele and is capital ________________

• Dominant

• Homozygous

• Genotype

• Phenotype

Multiple Choice

Heterozygous is when...

• the alleles are the same

• the alleles are different

• the alleles are absent

• the alleles are present

Multiple Choice

What allele combination should go in the missing box?

• AA

• Aa

• aa

• none of these

Multiple Choice

How many boxes would say BB?

• 1

• 2

• 4

• 0

Genotype and phenotype ratio and percentages

In four squares, each square represents 25% of the total or 1/4.

Multiple Choice

What are the chances that the offspring will have homozygous recessive traits?

• 1 in 4

• 3 out of 4

• 75%

• 50%

Multiple Choice

The genotypic ratio here is

• 25% blue eye 75 % brown eye 

• BB = 25% Bb = 50% bb = 25%

• BB= 50 % bb = 50%

• All brown eye

Multiple Choice

What is the genotypic ratio represented by the punnett square?

• 1:1

• 3:1

• 1:3

• 1:2:1

A genotype is the genetic sequence we write with letters and phenotype is the physical trait we see expressed

Multiple Choice

What is a phenotype

• The genetic make up (code)

• The physical trait

Multiple Select

In guinea pigs, short hair (H) is dominant to long hair (h). Also, black eyes (B) are dominant to red eyes (b).

Determine the genotype of a guinea pig with the phenotype: short hair with red eyes (select all possible genotypes)

• HHbb

• Hhbb

• hhBB

• HHBb

Multiple Select

A person with the genotype BBMm could produce which of the gametes below ...

• Bb

• BM

• bM

• Bm

Multiple Choice

Based off this punnett square, what fraction of the offspring will have wrinkled, yellow seeds?

• 9/16

• 3/16

• 1/16

• 16/16

Multiple Choice

What goes in box 15

• aabb

• AABB

• aaBB

• AAbb

Multiple Choice

Cross Two Homozygous plants
(RRYY x rryy)
R = round seeds, r  = wrinkled seeds Y = yellow seeds, y = green seeds
What percent will have Round and Yellow seeds? 

• 0%

• 25%

• 50%

• 100%