Biology final study guide

- Mendelian Genetics, Non Mendelain genetics, and pedigrees and evoulution

Evoulution

• Changes in a species that have occurred over time

These changes are inheritedfrom parents

Ideas about life before Darwin

1. species are fixed or permanent and do not change through time.

2. Earth is less than 10,000 years old and unchanging.

Fitness

how successful you are at reproducing

Gene Pool

all possible genes within a population

Natural selcetion Requirements

1. Variation 

2. Heritability

3. Differential Fitness

Natural Selection

the process by which organisms better adapted to their environment tend to survive and produce more offspring

Variation

Organisms within a population must differ from one another in at least one trait

Heritablity

Traits must be able to be passed from parents to offspring

Differential Fitness

Individuals with different phenotypes of a trait are not as likely to survive and reproduce as others

Adaptation

• A genetically controlled trait increases an individual’s ability to pass along its alleles and betters its chance of survival

Homologous Structures

• similar in structure, and evolutionary origin but might have different function (ex. arm and flipper)

Analogous Structures

similar function, but very different anatomical structure
(ex. birds

Structural adaptations

• Ex: Camouflage or Mimicry

• Different types of teeth (think carnivore vs. herbivore)

Behavorial adaptations

• activities that help them survive.

  • Migration – for more food, shelter, etc.

  • Social behavior – Living alone or in a group

  • For protection – “Playing dead”

Chromosomes

Chromosomes are long, tightly coiled lengths of DNA found in the nucleus of each cell

Human chromosomes (pairs, and total)

There are 23 pairs of human chromosomes (46 typical total)

autosomal traits

Traits located on an autosome

sex linked traits

Traits that are on one of the sex chromosomes (usually the X chromosome)

Female chromosomes

XX

Male Chromosomes

XY

Genotype

Combination of alleles (letters-Hh,HH,or Hh)

Homozygous

Both letters represent same alleles (aa,AA)

Phenotype

expression or physical traits in an organism (wavy or tall)

Heterozygous

Hybrid or both alleles (Aa)

Gregor Mendels Three Laws

• law of Segregation

• Law of Dominance

• Law of Independent Assortment

what did medel do?

• Used self-pollinating pea plants to study genetics in mid-1800’s

Law of segregation

During gamete formation the 2 alleles a person has segregate into separate gametes. 

Law of dominance

• Dominant (capital letters - B) traits overpower the expression of recessive traits (lowercase letters - b)

Law of independent assortment

• Homologous chromosomes line up randomly in the cell during metaphase 1.

Non mendalian inheritance

any pattern of inheritance in which traits do not follow the rules described by Gregor Mendel.

Codominance

Both alleles are completely dominant together.

Multiple alleles

• More than two alleles exist for a gene.

  • Each individual has two copies of allele but many combinations exist.

  • Ex: rabbit coat color.

  • Ex: Human A,B,O blood type

polygenic traits

Polygenic traits are controlled by more than one gene.

blood type comes from…

Codominance & Multiple Allele Patterns of Inheritance

Antigens

• Antigens are molecules on the surface of red blood cells.

antibodies

• Antibodies are proteins in the plasma.

pedigrees

• A chart that shows the relationships within a family to determine the pattern of inheritance for a particular trait.

Dominant traits

• If a trait is dominant, it will appear in every generation.

Resccive traits

• If a trait is recessive, it tends to skip generations.