whose got genes n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Whose got Genes? PowerPoint Presentation
Download Presentation
Whose got Genes?

Loading in 2 Seconds...

play fullscreen
1 / 37

Whose got Genes? - PowerPoint PPT Presentation


  • 208 Views
  • Uploaded on

Whose got Genes?. Genes, Heredity, & DNA. What are genes? . Genes are a segment of DNA on a chromosome that controls a particular trait. Genes are located on the chromosomes in the nuclei. Each organims has a fixed number of chromosomes. Humans have 23 pairs (46) chromosomes.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Whose got Genes?' - jon


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
whose got genes

Whose got Genes?

Genes, Heredity, & DNA

Baker 2003/2004

what are genes
What are genes?
  • Genes are a segment of DNA on a chromosome that controls a particular trait.
  • Genes are located on the chromosomes in the nuclei. Each organims has a fixed number of chromosomes.
  • Humans have 23 pairs (46) chromosomes.
  • Genetics is the study of how traits are passed on from one generation to another

Baker 2003/2004

so what is dna
So what is DNA?
  • DNA is a complex molecule (polymer) found in all living things.
  • The primary function of DNA is to store and transmit genetic information that tells cells which proteins to make and when to make them.

Baker 2003/2004

dna trivia
DNA TRIVIA
  • An idea about size:
    • An average cell nucleus is about 6 micrometers in diameter.
    • The total length of the DNA in the human genome is 1.8 meters.
    • There must be several levels of coiling and super coiling in DNA

Baker 2003/2004

who was gregor mendel1
Who was Gregor Mendel?
  • Austrian monk who studied mathematics and science
  • As a boy he could predict the possible types of flowers and fruits that would result from crossbreeding two plants in his father’s garden

Baker 2003/2004

who was gregor mendel2
Who was Gregor Mendel?
  • Curiosity about the connection between the color of a pea flower and the type of seed that same plant produced inspired him to begin experimenting with garden peas in 1856.
  • Made careful use of scientific methods, which resulted in the first recorded study of how traits pass from one generation to the next.

Baker 2003/2004

what is genetics
What is GENETICS?

Baker 2003/2004

what is genetics1
What is GENETICS?

The study of how traits are inherited through the interactions of genes.

Baker 2003/2004

what is a gene
What is a GENE?

Baker 2003/2004

what is a gene1
What is a GENE?
  • The material that controls which traits are expressed in an organism
  • Genes come in pairs and offspring inherit one copy of each gene from each parent

Baker 2003/2004

define the following terms
Define the following terms:
  • Heredity
  • Allele
  • Trait

Baker 2003/2004

define heredity
Define HEREDITY

The passing of traits from parent to offspring

Baker 2003/2004

define allele
Define ALLELE
  • The different forms of a trait that a gene may have
  • One form of a gene

Baker 2003/2004

define trait
Define TRAIT
  • Ways of looking, thinking, or being
  • Traits that are genetic are passed down through the genes from parents to offspring

Baker 2003/2004

describe recessive
Describe RECESSIVE

Baker 2003/2004

describe recessive1
Describe RECESSIVE
  • A trait that is covered over, or dominated, by another form of that trait and seems to disappear
  • Hidden when the other copy of the gene contains the dominant allele.
  • A recessive allele shows up only when there is no dominant allele present
  • Shown with a lower-case letter

Baker 2003/2004

what is homozygous
What is HOMOZYGOUS?

Baker 2003/2004

what is homozygous1
What is HOMOZYGOUS?
  • Both alleles [forms of the gene] are the same
  • When offspring inherit two dominant genes, (one dominant gene from each parent) they are said to be homozygous dominant
  • When offspring inherit two recessive genes, (one recessive gene from each parent) they are said to be homozygous recessive

Baker 2003/2004

what is heterozygous
What is HETEROZYGOUS?

Baker 2003/2004

what is heterozygous1
What is HETEROZYGOUS?
  • When alleles occur in different forms
  • When offspring inherit one dominant gene and one recessive gene, they are said to be heterozygous
  • Since the dominant gene will be expressed, they are said to be heterozygous dominant

Baker 2003/2004

describe dominant
Describe DOMINANT

Baker 2003/2004

describe dominant1
Describe DOMINANT
  • A trait that covers over, or dominates, another form of that trait
  • Trait that always shows up, even when only one of the two alleles is in the dominant form
  • Shown by a capital letter

Baker 2003/2004

define genotype
Define GENOTYPE

Baker 2003/2004

define genotype1
Define GENOTYPE

An organism's genetic makeup

Baker 2003/2004

define phenotype
Define PHENOTYPE

Baker 2003/2004

define phenotype1
Define PHENOTYPE

Outward physical appearance and behavior of an organism

Baker 2003/2004

what is a punnett square
What is a PUNNETT SQUARE?
  • A tool to predict the probability of certain traits in offspring that shows the different ways alleles can combine
  • A way to show phenotype & genotype
  • A chart that shows all the possible combinations of alleles that can result when genes are crossed

Baker 2003/2004

what is a punnett square1
What is a PUNNETT SQUARE?
  • Letters stand for dominant and recessive alleles
  • An uppercase letter stands for a dominant allele
  • Lowercase letters stand for recessive alleles

Baker 2003/2004

introduction to punnett squares
Introduction to Punnett Squares:
  • A Punnett Square is a chart drawn to determine the probable results of a genetic cross. To be able to draw a Punnett Square, you must know the genotype of both parents.

Baker 2003/2004

punnett squares
Punnett Squares
  • Sample Problem 1.   In roses, red flowers are dominant over white flowers. What are the possible offspring when a homozygous red rose is crossed with a homozygous white rose.

Baker 2003/2004

generation 1
Generation 1

homozygous red rose = RR

homozygous white rose = ww

Baker 2003/2004

generation 2
Generation 2

homozygous red rose = RR

heterozygous red rose = Rw

homozygous white rose = ww

Baker 2003/2004

generation 3
Generation 3

homozygous red rose = RR

heterozygous red rose = Rw

homozygous white rose = ww

Baker 2003/2004

list the 3 principles of heredity1
List the 3 Principles of Heredity
  • Traits are controlled by alleles on chromosomes
  • An allele’s effect is dominant or recessive
  • When a pair of chromosomes separate during meiosis the different alleles for a trait move into separate sex cells

Baker 2003/2004

references
References
  • Slideshow adapted from http://www.science-class.net/PowerPoints/Genetics.htm

Baker 2003/2004