1. Traits and How They Change Traits and the Environment

2. What are traits? Observing Traits Phenotypes and Genotypes
Traits are features organisms inherit.
To improve organisms, they were breed using desired observable traits.
Phenotypes and Genotypes
DNA – coded info of hereditary material in every cell, shaped like twisted ladder
Gene – part of DNA code on a chromosome
Genotype – genetic makeup
Phenotype – observable traits

3. Effects of the Environment
Growth
Trees are in competition for environmental factors in a forest
Compete for light, water, soil minerals
Effects tree population
Appearance
Organism may have same genes, but appearances can be different if not in same environment (water buttercup plant)
Temperatures where an organism lives can change an organisms phenotype (Siamese cat and Arctic Fox)

4. Gender Some species of fish have ability to change genders (clownfish)
Helps maintain desired male-to-female ratio
Switch back and forth depending on number of males and females in population

5. Questions Write out each question & Answer in Complete Sentences for Full Credit!!!
What are traits?
How were organisms improved?
What is an organism’s genotype?
What is a phenotype?
Which 3 environmental factors effect the population of trees?
How do organisms with the same genes look different?
Why are some species of fish able to change back and forth from male to female?

6. Traits and How They Change
Genetics

7. Science of Genetics What is genetics?
Heredity – passing of traits from parents to offspring
The study of heredity is genetics
Genetics and cell processes explain how species change over time

8. Beginning with Mendel Dominant and Recessive Traits
Gregor Mendel first to use numbers describing results of genetic experiments
Conclusion – traits are determined by different factors (factors = genes)
Allele – different forms of a gene
Principle of Dominance – when only one form of a trait is shown when both alleles are present.
Dominant Alleles – show effect on phenotype whenever present in genotype.
Recessive Alleles – show effect on phenotype only when 2 of them are present.

9. From Parents to Offspring
Principle of Segregation – each parent passes only one allele for each trait to its offspring.
Explains how offspring can look different from each other
Each sex cell has 3 chromosomes, which can be combined in 8 possible ways
Humans have 46 chromosomes, so 8 million combinations are possible every time sex cells form
Law of Independent Assortment – different traits are inherited with no relation of each other

10. Predicting Genetic Outcomes
Punnett Square
Makes genetic predictions by crossing different organisms with known genotypes
Hybrid – organism with 2 different alleles for a trait
Monohybrid Cross – only one trait, make predictions difficult
Understanding Results
Each result is independent of the ones that came before and after
Probability the prediction is right increases when large numbers are studied

11. Questions – Write ?’s out and Answer in Complete Sentences!!!
What is genetics?
What is the Principle of Dominance?
Which type of allele is shown in the phenotype when two are present?
How is offspring explained when they do not look the same?
How many chromosomes can be found in humans?
What is a Punnett Square?
How can the predictions made by a Punnett Square become more reliable?

12. Traits and How They Change Environmental Impact Over Time

13. Survival and the Environment
Nonliving Influences
Temperature and rainfall
Pollution affect survival
Factors can change species appearances
Fire, height of mountains, volcanic activity, and flooding can be positive or negative factors
Interactions with Other Organisms
Predators
Availability of food
Population of species

14. Species and the Environment
Natural Selection (Charles Darwin)
Evolution – changes that happen over time due to adaptation to the environment.
Natural Selection – organisms that are better adapted to survive and reproduce at a greater rate than another, produces new species.
Mutation
Process where DNA changes result new alleles
Some can be advantageous for survival and reproduction and trait is passed on
Some can keep an organism from surviving and reproducing

15. Direction of Evolution
Selective Breeding
Humans can select different variations to produce many different breeds
Could happen naturally in an environment
Direction of Evolution
Natural Selection can lead to 2 or more new species if more than one variation of a trait is favored
Adaptive Radiation – production of several species from one ancestral species

16. Extinction of Species Last individual of species dies
Rate of extinction today is as great or greater than the past
Reasons for extinction:
Destruction of habitat
New species
Human impact
Predators
Overcrowding

17. Questions
What nonliving influences affect the survival of species in an environment?
How do other organisms affect the survival of a species?
What is natural selection?
When is a mutated trait passed on to offspring?
What causes the production of several species from one ancestral species?
What are the causes of extinction?