Final Biology Test

Heredity

Heredity

The passing of traits from parent to offspring

Allele

• The variation of the gene that you get from each parent

• 1 letter = 1 allele

Genotype

• The genetic make-up of an organism

• We use letters to depict the trait that you got from each parent

• Always use the first letter of the dominant trait

  • The capital letter is dominant

  • The lowercase letter is recessive

3 Possible Genotypes

• TT: Purebred Dominant & Homozygous Dominant

• tt: Purebred Recessive & Homozygous Recessive

• Tt: Hybrid & Heterozygous

Phenotype

• Your phenotype is your physical appearance or your characteristics

• You can physically see your phenotype, not your genotype

What is DNA & Where is it found?

• It is a molecule that carries the genetic code to make proteins

• Proteins determine your traits

• DNA is coiled up in the nucleus of every cells, in structures called chromosomes

Relationship between DNA & Chromosomes

DNA + Gene = Chromosomes

What does DNA look like?

• DNA looks like a twisted ladder or a double helix

• The sides of the ladder are made of sugar and phosphate

Structure of DNA

• DNA is made up of Nucleotides

• One Nucleotide = Sugar + Phosphate + Base

Nitrogenous Bases

• Pairs of nitrogenous bases form the steps

• They are held together by hydrogen bonds

• The nitrogen bases include:

  • A= Adenine

  • T= Thymine

  • G= Guanine

  • C= Cytosine

Body Structure

Humans share the same set of arm bones with cats, whales, and bats.

Comparing Embryos

The similarities found in the embryos of species that grow up to very different are evidence of common ancestry.

DNA Evidence

The strongest evidence that we have to support common ancestry is the DNA that we share.

Fossil Record

Species from the past were very different than they are today.

Asexual Reproduction Advantages

• Takes Less Time

• Organisms don’t have to find a mate

Sexual Reproductions Advantages

Variations in offspring can adapt to new environments or resist disease

Asexual Reproduction Disadvantages

Offspring are identical to the parent - no variations of change in environment or disease

Sexual Reproduction Disadvantages

• Takes more time

• Organisms have to find a mate

Order of Classification

Group

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Punnett Squares

The Punnett square is a square diagram that is used to predict the genotypes of a particular cross or breeding experiment.