Punnett Square
What is the purpose of a Punnett Square?
To predict the possible genetic combination of offspring.
What is the shape of DNA called?
The shape of DNA is called a Double Helix
What is a genetic mutation?
A genetic mutation is a change in the DNA sequence.
A type of cell division that reduces the number of chromosomes by half, and ensures that offspring have the correct number of chromosomes
When is our Biology Exam?
Friday December 13, 2024
How to determine the probability of offspring if one parent has a homozygous dominant (AA) and the other is heterozygous (Aa)?
The resulting genotype are 50% AA and 50% Aa having the probability of the offspring inheriting the dominant trait of 100% from both parents.
Which molecules make up the backbone of the DNA Structure?
The backbone of DNA is made up of Sugar and phosphate molecules
What are the different types of mutations?
1) Substitution
2) Deletion
3) Insertion
4) Inversions
Why is meiosis important?
Meiosis is important because it creates genetic diversity by mixing up genes from the parents and ensures that each parent gives half of genetic material.
How many questions will be on the exam?
35 Questions!
If two heterozygous parents (Aa) are crosses, what are the possible genotypes & phenotypes of their offspring?
When crossing two heterozygous parents (Aa), the Punnett Square will show a 25% AA, 50% Aa & 25% aa. The phenotype will be 75% dominant trait (AA & Aa) and 25% recessive trait (aa).
What are the 4 nitrogenous bases found in DNA?
1) Adenine (A)
2) Thymine (T)
3) Cytosine (C)
4) Guanine (G)
What are the two levels of mutations?
DNA Level & Chromosomal Level
How many cell divisions occur in meiosis?
Meiosis involves two rounds of cell division.
What are some topics that will be on the exam?
1) DNA Structure
2) Punnett Square
3) Mutations
4) Meiosis
How can a Punnett Square determine an unknown/missing genotype?
The unknown/missing genotype can determine by observing the phenotypes of the resulting offspring.
How do the nitrogenous bases pair up in the DNA structure?
In the DNA structure, Adenine (A) pairs with thymine (T), and Cytosine (C) pairs with guanine (G).
What are 2 kinds of diseases caused by mutations?
Sickel Cell Anemia, Down Syndrom
What are homologous chromosomes?
Homologous chromosomes are pairs of chromosomes that have the same genes but may have different versions of those genes. Having one pair of gene from each parent.
Who is known as the father of genetics?
Mendel
What else can a Punnett Square predict, besides offspring?
1) Crossing Plants,
2) Animals
3) Missing Genotypes
What hold the two strands of DNA together?
The two strands of DNA are held together by hydrogen bonds between the nitrogenous bases.
Which 2 mutations cause most problems and why?
Deletion & Insertion: The entire copy strand of DNA is off balance.
What is crossing over, and why is it important?
Crossing over is a process during meiosis where chromosomes exchange pieces of genetic material. Creating combinations of genes.
DNA has how many nucleotide bases?
4!