GeneticsGenetics

Genetics is the branch of science that studies _________.

________ is the passing of traits from parents to offspring.

heredity

Heredity

GregorGregor MendelMendel

Did his research in the __________ Born in 1822 in __________ Wanted to figure out why some

_______ showed up more often then others

Studied garden _____ plants

monastery

Austria

traits

pea

Why Pea Plants? Why Pea Plants? ____ _________ -has both male and

female reproductive structures on the same plant– Able to grow ____ ________ plants. Plants

self pollinate therefore were exactly like the parent.

_____ __________-pollen from one plant fertilizes the ovule of a different plant – Carried by _______ or _________

Self Pollinating

true breeding

Cross Pollination

wind insects

CharacteristicCharacteristic

A __________ that has different _______ in a population

_______ different forms of a characteristic

– __________ or ____________

featureforms

Traits

Dominant recessive

Dominant TraitDominant Trait

The trait present in the _______ generation

Dominant alleles are symbolized with __________ letters

first

capital

Recessive TraitRecessive Trait

The trait that seems to _______ into the background

Does NOT show up as _______ A trait that _________ in the second

generation after _____________ in the first generation when parents with different traits are bred

Recessive alleles are symbolized with _________ letters

recede

often

reappearsdisappearing

lowercase

RATIORATIO

Relationship between two different Relationship between two different numbers that is often expressed as a numbers that is often expressed as a fraction fraction

Traits and InheritanceTraits and Inheritance

________-instruction for inherited traits– One from each __________

_________-different forms of a gene

__________-an organism’s appearance __________-an organism’s genetic

makeup

Gene

parent

Alleles

Phenotype

Genotype

_______________ an organism that has _____ dominant or two _______ alleles. ____________

_______________ an organism has both a __________ AND a ___________ allele. _________

Homozygoustwo recessive

Purebred

Heterozygous

dominantrecessive hybrid

Gregor Mendel ReadingGregor Mendel Reading

1. How long was the 1. How long was the experiment expected to last? experiment expected to last?

The experiment was expected to last seven years.

2. Why use pea plants? 2. Why use pea plants?

Gregor Mendel used pea plants Gregor Mendel used pea plants because they were able to because they were able to self self pollinatepollinate and and easy to groweasy to grow. .

3. 3. Why was the F1 generation referred to as being hybrid tall?

There was one dominant and one recessive allele. The recessive allele is hidden.

Heredity In Plants READINGHeredity In Plants READING 1. The passing of characteristics from

parents to offspring is known as ____________

2. The scientific study of heredity is called __________

3. The offspring of two purebred plants with contrasting traits is called a _____________

4. A _________ trait will occur more often then a ____________ trait.

heredity

genetics

hybriddominant

recessive

Chapter 5 Section 2Chapter 5 Section 2

1. In __________ reproduction, only one parent cell is needed for reproduction.

2. In __________ reproduction, two parent cells join together to form a new individual.

3. Human body cells have ___ chromosomes.

asexual

sexual

46

4. Human _____ _____ have only ___ chromosomes-half the usually number. Male sex cells are called _____. Female sex cells are called ________.

5. _________produces new sex cells with half the usual number of chromosomes.

6. Genes are located on __________.

sex cells 23

spermegg

Meiosis

chromosomes

7. ____ ____________ carry genes that determine whether the offspring is male or female.

8. Females have _____ chromosomes. 9. Males have _____ chromosome and

____ chromosome. 10. THINK! Explain the difference

between sex cells and sex chromosomes.

Sex chromosomes

2 X

1 X1 Y

10. 10. THINK! Explain the difference between sex cells

and sex chromosomes.

Each sex cell (egg or sperm) contains half of all the chromosomes, including one sex chromosome. The sex chromosome genes are what determine whether an offspring will be male or female.

Punnett Square Punnett Square

DirectionsDirections

Chromosomes are made of ______ Genes must be able to supply

__________ for cell processes and for ________ cell structures

________ and ______ build models of DNA. They conclude that DNA resembles a twisted ladder shape known as a ______ _____

DNA

instructionsbuilding

Watson Crick

double helix

The structure of DNA can be compared to a _______ ______

___________ __________ is when a trait does not blend together but each allele has his own degree of influence.

Many things in your ___________ also influence how you grow and develop – Example:

twisted ladder

Incomplete Dominance

environment

amount of food

Chapter 6 Section 2Chapter 6 Section 2

___________ act as a chemical messenger

__________ occur when there is a change in the order of bases in a organism’s DNA

The three possible consequences to changes in DNA include: – __________________– __________________– __________________

Proteins

How tall you are

Eye color

Mutations

an improvement

no change at alla harmful change

A ________ is anything that can cause a mutation in DNA

_________________ is a disease that affects red blood cells

Genetic __________ provides information and counseling to couples who wish to have children but are worried that they might pass a disease on to their ________

mutagen

Sickle Cell Anemia

counseling

children

A __________ is a diagram for tracing a trait through generations of a family.

In _________ ________ organisms with desirable characteristics are mated to produce a new breed.

This process of _________________ allows scientists to transfer genes from one organism to another.

Pedigree

selective breeding

genetic engineering

Genes VideoGenes Video