Heredity Film and Gregor Mendel
What do most living things typically look like? Their Parents
What are some features your parents influence about the way you look? Eye color, hair color, nose,…
What are traits? The physical characteristics an organism shows and performs
What does it mean when we say you have inherited traits? These are traits received from the genes
of parents, grandparents or others in an organisms’ family tree.
Define Phenotype The physical appearance of a particular trait
Where are genes located in the cell?
Cell
Nucleus
Chromosomes
Genes
What is the material that makes up genes and chromosomes? DNA(Deoxy-Ribonucleic Acid
Define Heredity: All branches of science related to understanding how genes are passed from one
generation to another and their influence on an organisms functions and life expectancy
Define Genotype the genetic combination for any trait, all the genetic coding for an organism
Who is the Father of Genetics? Gregor Mendel
What type of plants did he do his experiments with? Pea plants for the most part
When he crossed Pure Tall Pea plants with Pure Tall Pea plants what resulted? Tall Pea Plants
When he crossed short pea plants with short pea plants what resulted? Short Pea Plants
When he crossed a short pea plant with a tall pea plant what resulted in the first generation?
100% Tall Pea Plants
When he crossed a two tall plants from the first generation from a cross between a Tall and
Short parent, what did the offspring look like? 75% Tall Pea Plants and 25% Short Pea Plants
About how many combinations of genes make up who you are? about 30,000
Define Dominant Trait The stronger trait, appears in phenotype whenever only 1 gene for trait
is present
Define Recessive Trait The weaker trait, appears in the phenotype only when two genes for
that trait is present in the genotype
What were the principles Mendel developed that define Genetics?
1. Mendel stated: all genes come in pairs
2. One trait is dominant over another trait.
3. Define Pure Bred (Homozygous) the two genes for a trait are the same (ex. FF, or ff)
4. Define Hybrid (Heterozygous) the two genes for a trait are different (ex. Ff)
Who is Reginald Punnett? English scientist who studied the work of Gregor Mendel and designed a
system for identifying the genotype of any particular trait
What letter do we use to indicate a Dominant Trait? CAPITAL LETTER
What letter do we use to indicate a Recessive Trait? lowercase letter
Draw a Punnett Square below and label it using the Gerbil Genotypes from the film.
F
F
f
Ff
Ff
f
Ff
Ff
What percent of the offspring showed the dominant trait? 100%
What percent of the offspring were Hybrids? 100%
Draw a second Punnett Square using the Hybrid parents below.
F
f
F
FF
Ff
f
Ff
ff
What percent of the parents showed the dominant trait this time in the offspring? __75%__
How many were pure for the dominant trait? 25%
How many were Hybrids? 50%
How many showed the recessive trait? 25%
What do genes do for the cell? Directs the cells to make proteins
Describe the structure of DNA. A double Helix or twisted ladder shape
How many pairs of chromosomes does a Cat have?
How many pairs does a dog have?
Humans? 46 Chromosomes (23 pairs)
Does more chromosomes mean you’re more complicated? Not at all
Define Meiosis The cell division of reproductive cells resulting in 4 new gametes with only one set of
chromosomes instead of the usual pair.
How many cells are produced after Meiosis is complete? 4 gametes
How many chromosomes do these cells have compared to the original cell? 23 only instead of 46
What is the scientific name of these cells? Gametes
What is a gamete called when produced in a female? Egg
What is a gamete called when produced in a male? Sperm
The rungs of the DNA ladder are made up of Nitrogen Base Pairs.
What does the letter A
stand for?
Adenosine
What does the letter T
stand for?
Thiamine
What does the letter G
stand for?
Guanine
What does the letter C
stand for?
Cytosine
How does the DNA get copied by the cell? Messenger RNA gets sent from the nucleus
What is an amino acid? Building blocks of Proteins, you need three amino acids to begin a protein
What could a change in the DNA structure lead to in an organism? Mutations are changes in the DNA
sequencing