2014 Genes and Heredity
-
Upload
fjhscience -
Category
Technology
-
view
1.310 -
download
0
Transcript of 2014 Genes and Heredity
![Page 1: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/1.jpg)
GENETICS &
CLASSIFICATION
GENETICS &
CLASSIFICATION
http://youtu.be/Mehz7tCxjSE?t=13s
![Page 2: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/2.jpg)
Heredity
• Gregor Mendel
• Austrian Monk
• studied garden pea plants to unveil patterns of heredity
• Developed the Laws of Inheritance
• Mendel noticed that traits from the pea plant parents didn’t always show up in their offspring
![Page 3: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/3.jpg)
Heredity• 2 types of traits were identified:
– Dominant trait – trait that appears in the offspring, offspring only needs one dominant allele from the parent to show up
– Recessive trait – trait that fades in the background or may not show up in the offspring, only shows up if the offspring gets two recessive alleles from their parents
– Mendel noticed that certain traits would reappear in later generations
![Page 4: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/4.jpg)
GenesMendel discovered that each
individual carries 2 sets of characteristics (genes)
Each offspring has two forms of a gene (one from each parent)
Genes - carry information that determines your traits.
![Page 5: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/5.jpg)
GenesGenes
Where are They?
• Genes hang out all lined up on thread-like things called Chromosomes.
– The chromosomes and genes are made of DNA which is short for deoxyribonucleic acid.
• Chromosomes are found inside cells–Specifically in the nucleus of the cell. (the
nucleus is sort of like the brain of the cell)
Where are They?
• Genes hang out all lined up on thread-like things called Chromosomes.
– The chromosomes and genes are made of DNA which is short for deoxyribonucleic acid.
• Chromosomes are found inside cells–Specifically in the nucleus of the cell. (the
nucleus is sort of like the brain of the cell)
![Page 6: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/6.jpg)
Genes
![Page 7: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/7.jpg)
Alleles
Allele - different form(s) of a gene, responsible for hereditary variation.
– Dominant trait – appears if it inherits the gene for that trait from either parent; will always be expressed and will “mask” a recessive trait. Shown by capital letter(s).
– Recessive trait – appears only if it inherits that trait from both parents and can only be expressed if there are no dominant alleles present; shown by lower case letters.
![Page 8: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/8.jpg)
Alleles• Genotype –The alleles present in an organism.
inherits from its parents, the actual gene makeup represented by letters.
• (Example: BB, Bb, or bb)
“Purebred”, also called Homozygous consists of gene pairs with genes that are the same. (Example: “RR” -or- “rr”)
“Hybrid”, also called Heterozygous and consists of gene pairs that are different. (Example: “Rr”) • Note: The capital letter always is written first.
This is the "internally coded, inheritable information" carried by all living organisms.is
.
BB Bb bb
![Page 9: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/9.jpg)
• Phenotype – is the physical appearance of a trait.What it looks like…
– Example: blue eyes or brown hair
• These are the physical parts, anything that is part of the observable structure, function or behavior of a living organism.
Alleles
Red Red WhitePhenotype---------
![Page 10: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/10.jpg)
Punnett SquarePunnett Square
Punnett Square - a diagram used to predict outcomes of genetic combinations. The Punnett square is a summary of every possible combination of one maternal allele with one paternal allele for each gene being studied in the cross.
Steps for Using the Punnett square:
– One parent’s alleles (genotype)(genotype) go along the top– The other parent’s alleles go down the side.– You fill in the squares like doing the communicative
property of multiplication.
Punnett Square - a diagram used to predict outcomes of genetic combinations. The Punnett square is a summary of every possible combination of one maternal allele with one paternal allele for each gene being studied in the cross.
Steps for Using the Punnett square:
– One parent’s alleles (genotype)(genotype) go along the top– The other parent’s alleles go down the side.– You fill in the squares like doing the communicative
property of multiplication.
![Page 11: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/11.jpg)
Punnett SquarePunnett SquarePractice: Both parents have the same genotype (Bb)B= brown hair color b= blond hair color
Fill out the Punnett square on the right to help answer the following questions.
This organism has ________% or __________chance of receiving brown hair.
This organism has ________% or ____________ chance of receiving blonde hair.
The possible genotypes are:
The possible phenotypes are:
F
M
![Page 12: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/12.jpg)
ReproductionReproduction
• Asexual Reproduction – only need one parent to produce an offspring, offspring are exact copies of the parent. The genetic information passed to offspring is identical to that of the parent. – Produces uniform offspring– Most single-celled organisms reproduce this way
![Page 13: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/13.jpg)
ReproductionReproduction
• Sexual Reproduction – requires 2 parents to reproduce, offspring share characteristics from both parents and are not exactly like either parent– Produces more diverse offspring
![Page 14: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/14.jpg)
Survival and Reproduction
Charles Darwin first presented his theory of evolution by natural selection in his book called On the Origin of Species in 1859.
Natural Selection – organisms with favorable hereditary traits are more likely to survive and reproduce than other organisms; these organisms gradually increase their proportion of a species.
Charles Darwin first presented his theory of evolution by natural selection in his book called On the Origin of Species in 1859.
Natural Selection – organisms with favorable hereditary traits are more likely to survive and reproduce than other organisms; these organisms gradually increase their proportion of a species.
![Page 15: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/15.jpg)
Survival and ReproductionNatural Selection in 4 Steps:
– Overproduction – more individuals are born than will survive to adulthood
– Genetic variation – each individual in the species has different traits, some traits make an individual more likely to survive and reproduce.
– Struggle to survive – only some of the individuals in a population become adults and reproduce.
– Successful reproduction – individuals have traits that make them better adapted to their environment are more likely to reproduce.
• Example: Peacocks with dull feathers won’t survive, eventually all die off
![Page 16: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/16.jpg)
Survival and ReproductionExample:
Peacocks with dull feathers won’t survive to pass on trait, eventually all dull feathered peacocks will die off
![Page 17: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/17.jpg)
Overproduction
![Page 18: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/18.jpg)
Genetic Variation
![Page 19: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/19.jpg)
In the wild
Struggle to Survive
To find food
![Page 20: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/20.jpg)
Successful ReproductionModern Peahen, adapted to the
environment looks for Mr. Right.
Mr. Right
Mr. Right,shiny feathers..good hunter…
great traits
![Page 21: 2014 Genes and Heredity](https://reader034.fdocuments.in/reader034/viewer/2022052523/55506bcfb4c905cc0f8b487d/html5/thumbnails/21.jpg)
Darwin visited the Galapagos Islands off the coast of South America. There he made many observations. One of the most famous, was the Finch.