Download study of inherited traits

Name______________________________
Per_______
Date ______________
Genetics Unit Study Guide
Genetics Vocabulary
Characteristic
an identifying feature of a person or thing (example: eye color)
Trait
description of a specific appearance (version) of a characteristic
(example: blue eyes)
Inherit
to pass traits from parent to offspring (noun is heredity)
Genetics
study of inherited traits
Sexual Reproduction
offspring result from the combination of chromosomes from a male and
female parent
Asexual Reproduction
offspring have one parent and are an exact clone of the parent
Clone
an organism produced through asexual reproduction (all traits from 1
parent)
Mutation
a permanent change in the DNA sequence
Gene
specific section of DNA molecule that is responsible for a specific trait.
Genotype
The gene make up for a particular trait.
Phenotype
The physical expression of a particular trait.
Dominant Trait
expressed (seen) when one dominant version of gene (allele) is present.
(ex. blue tail critter with Tt genotype)
Recessive Trait
expressed (seen) when two versions of recessive gene (allele) are present
(ex. orange tailed critter with tt genotype)
Allele
one of two or more different forms of a gene (T or t )
Activity 54: Investigating Human Traits
Learning Target
You will explore human characteristics that are inherited versus acquired.
Questions:
1
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1.
Per_______
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What is the difference between a trait and a characteristic?
Characteristic- A feature or quality belonging typically to a person, place, or thing and serving to
identify it. (ie hair color)
Trait- description of a specific appearance of a characteristic. (ie brown hair)
2.
Do you think that all the traits were inherited? If so - explain why. If not – indicate which one(s) were not and explain why
you don’t think they were inherited.
All of the traits we examined were inherited. Some traits may be learned or environmental, such
as joint flexibility.
3.
If you studied more people in your area, do you think you would find more traits for each characteristic? Explain.
Yes, more traits will be found as more data is collected especially height. Others may show up
depending on class results.
4.
Be able to interpret and/or graph a list of traits.
If given a set of data, be able to arrange that data on a proper bar graph. Include a TITLE; xaxis labeled; x-axis proportionally marked; y-axis labeled; y-axis proportionally marked; data
plotted cleanly and clearly
Activity 55/62: Plants Have Genes, Too!
Learning Target
You will analyze plants to determine how traits are inherited
1.
Refer to your class’s data to describe the ratio between the colors of the offspring’s stems and leaves. How does this match
Mendel’s observation?
We got a 3:1 ratio (or close) and this is what Mendel recorded as well when crossing two heterozygous
parents.
Activity 56: Joe’s Dilemma
Learning Target
You will consider the advantages and disadvantages of genetic testing for inherited diseases
Questions:
1.
What is a syndrome?
A condition that causes a pattern of physical changes.
2.
Can you “catch” an inherited disease from another person, the way you can catch the flu? Explain.
2
Name______________________________
Per_______
Date ______________
No, it is not contagious, it is passed down through, or mutated in, genes. NOTE: You can only “catch”
infectious diseases that are caused by a virus, bacteria or small organism.
Activity 57: Copycat
Learning Target
You will hypothesize how traits are inherited from parent to offspring
Questions:
1.
In asexual reproduction of a bacteria cell, is it clear which cell is the parent and which cell is the offspring? Explain.
No, in asexual reproduction, each new organism produced is an identical copy of the parent.
2.
Your friend tells you, “Only single celled organisms reproduce asexually. After all, how could a multi-cellular organism do
that?” How do you respond to your friend?
Budding-Hydra; Rootlike Runner- strawberry plant
Note: your cells undergo asexual reproduction—make new blood cells, skin cells, sex cells (mitosis)
3.
Describe asexual reproduction in your own words in terms of parents and traits
…sexual reproduction produces a new cell that develops into an individual with traits from both parents.
….because no two sperm cells or egg cells contain exactly the same information, no two offspring produced by
the same parents are identical.
NOTE: This is why you do not look like your siblings.
4.
Fraternal twins result when two eggs are both fertilized by sperm cells and both develop into offspring. (Very common in
dogs and cats) Why are identical twins much more similar then fraternal twins?
Identical twins develop from the same egg and sperm. Fraternal twins develop from different eggs and
different sperm. If no two sperm and eggs are the same…no two fraternal twins can be the same!
5.
Explain how they clone an animal.
The nucleus is removed from two cells. The nucleus (containing all the genetic information) from one
(body) cell is put into the nucleus of the other egg cell.
This is then implanted into a mother and grown.
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Name______________________________
6.
Per_______
Date ______________
How is a clone different than an identical twin?
Clone is an exact copy of the parent—it is an asexual reproduction. Twins happen when a fertilized egg
splits before beginning to grow and develop. Two parents have been involved in making this new life.
Target
4
Name______________________________
Per_______
Date ______________
You will be able to use a model to explain how inherited genes are either dominant or recessive.
Activity 59: Gene Combo
1.
What was the offspring phenotype outcome of the mating of Ocean and Lucy (both heterozygous)? Use a Punnett Square to
explain your answer.
3:1 ratio (dominant to recessive)
T
2.
t
T TT
tT
t Tt
tt
Why is this outcome always true for the mating of two heterozygous parents?
One homozygous dominant
Two heterozygous
One homozygous recessive
3.
How did this differ from Skye (homozygous dominant) and Poppy (homozygous recessive)? Use a Punnett Square to explain
your answer.
T
4.
T
t Tt
Tt
t Tt
Tt
Why is this outcome always true for the mating of a homozygous dominant to a homozygous recessive?
All combine to heterozygous.
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Name______________________________
Per_______
Date ______________
Activity 60: Reading Mendel
Learning Target
You will discuss how Gregor Mendel discovered the behavior of genes.
Questions:
1.
List the advantages for Mendel using pea plants for his breeding investigation.
Grow into mature plants very quickly.
They produce numerous seeds rapidly.
Many observable characteristics that come in just two alternatives with no blending of these traits.
2.
Why did Mendel do so many crosses for the same characteristic?
So that he had a very large sample size.
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