Genetics- What do you recall | Summaries Genetics

This is your WHAT TO KNOW paper. It is a study guide and an intro and includes the things that you need to

know to do well on your assessments for this topic. The questions will not be the same as your assessment

questions, they will be different questions over the same topics.

1) Know all the following terms and how they relate to one another. Be able to give examples or recognize

them in a scenario:

 Codominance

 Incomplete Dominance

 Epistasis

 Polygenic

 Sex influenced

 Sex linkage

 Environmental genes

 Pleiotropy

 Carrier

 Gene Linkage

 Roan

 Blood Type

 Holandric

Be able to answer all of the questions below. Some of these things you should know already, some

you will need to fill in after the lecture. You can seek out your own answers, but this paper should but

used throughout the topic, not just once.

1) Predict what you think “non-Mendelian” inheritance is referring to.

2) Think about when Mendel did his work. Therefore what do you think is the reason that may have caused

Mendel to not be able to predict all possible inheritance patterns in nature?

3) REVIEW: What are Mendel’s 3 Laws? Explain what each law means.

4) One of Mendel’s Laws, we will never defy, which one do you think that is?

5) Read this information and as you do, highlight anything that is brand new to you! Use this information to

complete #6 below.

Complete dominance is an inheritance pattern where the dominant allele (noted as a

capital letter) always trumps the recessive allele when present. For example, if T, the dominant

allele, codes for a tall plant and t, the recessive allele codes for a short plant, than plants with

the genotypes TT or Tt will be tall. The only time the recessive phenotype is expressed is in the

homozygous recessive genotype (ex: the genotype tt codes for a short plant). In humans,

polydactyly (having extra fingers or toes) follows a simple dominance inheritance pattern.

Polydactyly is actually the dominant trait, but there is a low frequency of the dominant allele in

the population. Students may ask why polydactyly is rare if it is dominant.

Incomplete dominance inheritance occurs when the heterozygote (Tt) phenotype is a

blending of the dominant and recessive phenotypes. In the case of the homozygous dominant

(TT=tall) and homozygous recessive (tt=short) plant, the heterozygous (Tt) plant would be of

medium height. In humans, the trait for sickle cell anemia is incompletely dominant. A person

who is heterozygous for the sickle cell trait has less severe anemic symptoms than the

homozygous recessive person. Sickle cell heterozygotes are also resistant to malaria. Co-

dominant inheritance is when the heterozygote exhibits both the dominant and the recessive

phenotype. A black chicken (BB) mated with a white chicken (bb) will produce a heterozygous

(Bb) chicken, checkered with black and white feathers. Human blood type is inherited co-

dominantly. A mother with A type blood has blood cells with the A protein. A father with B type

blood has blood cells with the B protein. Their child with AB type blood has blood cells that

have both the A and the B protein.

Partial preview of the text

Download Genetics- What do you recall and more Summaries Genetics in PDF only on Docsity!

This is your WHAT TO KNOW paper. It is a study guide and an intro and includes the things that you need to know to do well on your assessments for this topic. The questions will not be the same as your assessment questions, they will be different questions over the same topics.

Know all the following terms and how they relate to one another. Be able to give examples or recognize them in a scenario:  Codominance  Incomplete Dominance  Epistasis  Polygenic  Sex influenced

 Sex linkage  Environmental genes  Pleiotropy  Carrier  Gene Linkage

 Roan  Blood Type  Holandric

Be able to answer all of the questions below. Some of these things you should know already, some

you will need to fill in after the lecture. You can seek out your own answers, but this paper should but

used throughout the topic, not just once.

Predict what you think “non-Mendelian” inheritance is referring to.
Think about when Mendel did his work. Therefore what do you think is the reason that may have caused Mendel to not be able to predict all possible inheritance patterns in nature?
REVIEW: What are Mendel’s 3 Laws? Explain what each law means.
One of Mendel’s Laws, we will never defy, which one do you think that is?
Read this information and as you do, highlight anything that is brand new to you! Use this information to complete #6 below. Complete dominance is an inheritance pattern where the dominant allele (noted as a capital letter) always trumps the recessive allele when present. For example, if T, the dominant allele, codes for a tall plant and t, the recessive allele codes for a short plant, than plants with the genotypes TT or Tt will be tall. The only time the recessive phenotype is expressed is in the homozygous recessive genotype (ex: the genotype tt codes for a short plant). In humans, polydactyly (having extra fingers or toes) follows a simple dominance inheritance pattern. Polydactyly is actually the dominant trait, but there is a low frequency of the dominant allele in the population. Students may ask why polydactyly is rare if it is dominant. Incomplete dominance inheritance occurs when the heterozygote (Tt) phenotype is a blending of the dominant and recessive phenotypes. In the case of the homozygous dominant (TT=tall) and homozygous recessive (tt=short) plant, the heterozygous (Tt) plant would be of medium height. In humans, the trait for sickle cell anemia is incompletely dominant. A person who is heterozygous for the sickle cell trait has less severe anemic symptoms than the homozygous recessive person. Sickle cell heterozygotes are also resistant to malaria. Co- dominant inheritance is when the heterozygote exhibits both the dominant and the recessive phenotype. A black chicken (BB) mated with a white chicken (bb) will produce a heterozygous (Bb) chicken, checkered with black and white feathers. Human blood type is inherited co- dominantly. A mother with A type blood has blood cells with the A protein. A father with B type blood has blood cells with the B protein. Their child with AB type blood has blood cells that have both the A and the B protein.

Finally, sex-linked inheritance refers to the genes that are carried on the sex chromosomes. Females are XX and males are XY. The X chromosome is much larger than the Y chromosome, and contains more genes. For this reason, most sex-linked traits in humans affect males more often than females. Some genes, like the recessive gene for colorblindness, are found only on the X chromosome and not the Y. Girls who inherit the gene for colorblindness from their mothers still have a chance to inherit the dominant, normal gene from their father. Boys who inherit the gene for colorblindness from their mothers don’t get that second chance because the Y chromosome they inherit from their fathers does not contain any gene for color vision, normal or not.

Use the reading above and your iPad or other device to research the following inheritance patterns. (Some do not come from the above readings) Briefly describe/define each: A) Codominance

B) Incomplete Dominance

C) Epistasis

D) Pleiotropy

E) Environmental Genes

Based on what you said in #6, place the examples below under the type of inheritance pattern you discovered or read about. A) Blood type B) Himalayan rabbit’s coat colors C) Result in disorders like sickle cell anemia D) Eye color E) Pink flowers from red and white parents
Explain the difference between codominance and incomplete dominance and be able to give examples of each.
What is “gene linkage”?
What Mendelian Law is directly defied by gene linkage?
Give several examples of polygenic traits.
Explain why sex linked traits are seen in males more often than females.
Explain why females can’t have holandric traits.

Genetics- What do you recall, Summaries of Genetics

Related documents

Partial preview of the text

Download Genetics- What do you recall and more Summaries Genetics in PDF only on Docsity!

Be able to answer all of the questions below. Some of these things you should know already, some

you will need to fill in after the lecture. You can seek out your own answers, but this paper should but

used throughout the topic, not just once.