Unit 7 Genetics

Lesson 1 – Mendel’s Pea Plants

Vocabulary: Trait: a characteristic an organism can pass on to its offspring

through DNA Inherited: traits that were passed on from parents to offspring

regardless of the environment

DNA: carrier of the genetic information

Gene: a segment of DNA that codes for a specific trait

Notes:

Gregor Mendel Noticed that pea plants had certain identifiable and measurable

characteristics or traits. Mendel observed that some characteristics such as flower color, seed

shape and seed color were inherited or passed on from parents to the offspring.

Mendel’s work led him to the understanding that traits, such a plant height, are carried in DNA.

Let’s Practice!

Matching

Characteristic an organism can pass on to its offspring through DNA.

Segment of DNA that codes for a specific trait.

Traits that were passed on from parents to offspring regardless of environment.

Carrier of genetic information

Inherited

DNA

GENE

Trait

Unit 7 Genetics

Lesson 2- Genes and Alleles

Vocabulary: ________________: tightly wound DNA

_________________: two different forms of a single gene

o ___________________: alleles that determines what the organism will look like (Upper case letter)

o ____________________: the allele that is not expressed in the organism unless both alleles are recessive (lower case letter)

Notes:

DNA Found in all living cells. Controls all functions inside the cell. It stores all the genetic information for an entire living organism.

Gene A segment of DNA that codes for a trait

Let’s Practice!

Unit 7 Genetics

True or False.

1. Alleles are the same form of a single cell. _______

2. Dominant Alleles determines what the organism will look like._____

3. DNA is found in all living cells. ___________

4. Chromosomes are tightly wound DNA. __________

5. DNA stores all genetic information for part of a living organism. ______

Lesson 3 – Inheritance

Unit 7 Genetics

Vocabulary: _____________________: passing on of traits from parent to offspring

Notes:

Inherited Traits A sperm cell will join with an egg cell and become fertilized and begin

to develop. Sex cells have the same number of chromosomes as other body cells

because one sex cell from each of two parents combines from a new organism.

o ___________: male sex cello __________: female sex cell

Every cell (other than sex cells) carries 23 pairs or 46 total of homologous chromosomes.

o Sperm carries 23 and an egg carries 23. When they join, the new offspring will have 46.

Homozygous vs Heterozygous Homozygous: both alleles in a pair of genes are the same

o Prefix homo means “the same”o AA = homozygous dominanto aa = homozygous recessive

Heterozygous: both alleles from a pair of genes are differento Prefix hetero means “different”o Aa= heterozygous

Genotype and Phenotype Genotype: actual Gene makeup Phenotype: the Physical appearance

Lesson 3 – Inheritance (con’t)

Unit 7 Genetics

Male and Female? In mammals, the two sex chromosomes are called X and Y. Females

have two X chromosomes (XX) and males have one X and one Y. (XY) The sperm only carries a single X or Y, so it is the father who determines the sex of a baby.

Let’s Practice!

Fill in the blank.Genotype | Heterozygous| Inheritance |Homozygous | Egg |Phenotype

1. ________________ is the passing on of traits from parent to offspring.

2. ___________________ means both alleles in a pair of genes are the same.

3. The female sex cell is called an ________.

4. _____________________ means both alleles from a pair of genes are different.

5. _____________________ is the actual gene make up and______________ is the physical appearance.

Lesson 4 – Punnett Squares

Vocabulary

Unit 7 Genetics

_____________________: a grid used to predict the results of genetic crosses

Notes:

Punnett Squares Reginald Punnett created a __________, which is a grid used to predict

the results of genetic crosses. This tool is called _________________________ Example: Showing cross between two black rabbits. Both

heterozygous for fur color (Bb). (Black is the dominant phenotype-B, white is the recessive phenotype- b)

Genotype vs Phenotype Genotype is the combination of alleles for a trait (BB, Bb, bb) Phenotype is the visible trait that an offspring exhibits (black or

white fur)

Let’s Practice!

Unit 7 Genetics

Black or Blue? Fill in the Punnet Square.

GO TO NEXT PAGE TO CHECK YOUR ANSWER!

ANSWER: There is a 50% chance the baby chick will be blue and a 50% chance it will be black.

Unit 7 Genetics

Lesson 7 – Similarities Among Organisms

Vocabulary

Unit 7 Genetics

_______________: group of organisms that closely resemble one another and are able to interbreed and produce fertile offspring

______________: differences that exist between individuals of the same species

o can be genotypic or phenotypic tall/short, dimples/no dimples

Notes: ________________ and _____________ are responsible for different traits in

a species.

Chromosomes

Each species carries a certain number and a certain kind of chromosomes.

Humans carry 46 chromosomes. Due to chromosomes, we would never confuse a human with a

different species of animal

Lesson 8 – Chromosomes

Vocabulary _______: (deoxyribonucleic acid)the code carrying material in our

body

Unit 7 Genetics

_________________________: shape of DNA

______________________: a single long molecule of DNA wound around special proteins

Notes:

Let’s Practice!Label the parts with the terms below. Use above as a guide

Cell | Chromosome |Gene |Nucleus

Lesson 9 and 10 – Meiosis

Vocabulary __________: male sex cells

DNA

Unit 7 Genetics

________: female sex cells

________________: sex cells (egg and sperm) (GAME of life)

______________- division of the nucleus of a cell forming two daughter cells, each receiving the same number of chromosomes

______________- a type of cell division resulting with ½ the chromosomes of the parent

Notes:

Meiosis Meiosis produces daughter cells that each have _________ the number

of chromosomes the parent has. A ____________ is the first cell of a new individual when egg and sperm

come together and contains a full set of chromosomes.o 23 from egg + 23 from sperm =46 from egg and sperm

Meiosis vs Mitosis

MITosis take the cell and Makes It Twoo Results in two genetically identical cells

Meiosis has to do with sex cellso Results in four genetically different cells

Lesson 9 and 10 – Meiosis (Con’t)

Mitotic phase: PMAT or People Meet And Talk ___________________- the chromosomes coil and become more compact,

the nuclear membrane breaks down, and a system of fibers called the spindle starts to form

Unit 7 Genetics

________________- the chromosomes arrange in a plane at the middle of the cell

________________- the chromosomes split and move apart _______________-_- the chromosomes reach two sides of a cell and are

incorporated into two new nuclei

Let’s Practice!

Answer the questions below. Use the study guide above to help find the answers.

1. What are sex cells called? _______________2. How many cells does MITosis make? __________3. How many cells does Meiosis make?_________4. What are the four steps in Mitosis?

___________________________________________________________________5. What is the first cell of a new individual when egg and sperm come

together and contains a full set of chromosomes?___________________--

Lesson 12 Mutations

Vocabulary _________________: any change in a gene or DNA (can be helpful,

harmful or have no effect at all)

Unit 7 Genetics

_________________: occurs when a single nucleotide is exchanged for another

_________________ one or more bases are REMOVED or left out of the DNA

_________________: one or more bases are added to the DNA

Notes:

Large-Scale Mutationso Large-Scale Mutations are more seriouso Large sections of chromosomes are changedo Sections of a chromosome may be duplicated

o May result in extra copies of a gene that may amplify the effects of that gene

o Large sections of a chromosome may be deleted, resulting in the loss of entire genes

Let’s Practice

Match the term with the definition.

Lesson 13:Genetic Engineering

Vocabularyo ________________________: process by which organisms with certain traits

survive to reproduce and pass on those traits to their offspring

Unit 7 Genetics

o ____________________________: the process of breeding organisms with the most desirable traits

o ___________________________: the manipulation of DNA to produce molecules or organisms with new properties

o ______________________: a process in which defective genes are replaced with normal genes

Notes:

Genetic Engineering Highly controversial issue today! For it:

o Using less pesticideso Growing more cropso Improving nutritional content of food

Against it:o It is trying to control natureo We don’t know how it could impact us down the road

Let’s Practice!Fill in the blank with words found below.

1. ______________________ is a process in which defective genes are replaced with normal genes.

2. ________________________ is the process of breeding organisms with the most desirable traits.

Unit 7 Genetics

3. ________________________ is process by which organisms with certain traits survive to reproduce and pass on those traits to their offspring.

4. _________________________ is the manipulation of DNA to produce molecules or organisms with new properties.

Word Bank:

Genetic Engineering | Natural Selection| Selective Breeding |Gene Therapy