Biology 30 Final Exam Review

Abiogenesis

Theory that life can from from non-living things.

Redi

Conducted an the rotting meet + flies experiment using mesh to prove biogenesis. No one believed him.

Needham

Proved abiogenesis by boiling mutton broth with a cork.

Spallanzani

Reviewed/ disproved Needham's experiments.

Louis Pasteur

Created to Swan's Neck Tube to prove the theory of biogenesis. Developed first vaccinations for rabies, anthrax, etc.

Van Leeuwenhoek

Developed the first microscope with lenses.

Robert Hook

Was the first to look at a cell, and name it a "cell".

Cell Theory

1. All living things are composed of cells.

2. Cells are the basic unit of life.

3. All cells arise from pre-existing cells.

Biogenesis

Life must come from living things

Characteristics of Living Things

- Living things are made up of cells

- Living things reproduce

- Living things are based on a universal genetic code

- Living things grow & develop

- Living things obtain & use material energy

- They respond to their environment

- Maintain a stable internal environment

- Taken as a group, living things evolve over time

Evolution

The change of a species over time.

Natural Selection

- Proved by fossil evidence

- Weak variations died off, favourable traits survived and species would reproduce so that these made up the majority of the population (survival of the fittest).

The Four Basic Principles of Natural Selection

1. Organisms have more offspring than that can survive (Over Production)

2. Individuals in a population show variation (Variation of traits)

3. These variations are inherited (Heritability)

4. Variations that increase survival or reproductive success will be more common in the next generations (If you're dead you cannot reproduce)

Evidence for Evolution

- Fossil Record

- Comparative Anatomy

- Comparative embryology and biochemistry

Analogous Structures (Comparative Anatomy)

Similar features in use, and evolve in similar environments but DO NOT EVOLVE FROM COMMON ANCESTOR.

Homologous Structures (Comparative Anatomy)

Used to describe anatomically similar structures inherited from a common ancestor.

Vestigial Structures (comparative Anatomy)

Ex. tail vertebrae & ear muscles & muscle in forearm that prove we are closely linked to other species.

Cladograms

Study physical traits

Phylogenetic Trees

Study genetics (DNA codes)

5 Principles of the Hardy-Weinberg Principle

1. No natural selection

2. No migration

3. No mutations

4. No genetic drift

5. No sexual selection

Principle of Dominance (Mendel's Laws)

- Dominant traits are expressed if only one allele is present.

- Recessive traits are expressed when dominant allele is not present.

- Explains why genotype differs from phenotype.

Law of Segregation (Mendel's Laws)

- Allele airs separate during gamete formation.

- Randomly unite at fertilization.

Law of Independent Assortment (Mendel's Laws)

- Alleles for different traits are distributed to sex cells independently

- Different traits are inherited INDEPENDENTLY.

.Incomplete Dominance (AKA Co-dominance)

- When you see more than 2 traits.

- Heterozygous = new phenotype

- Ex. when red flowers are crossed with white flowers and produce a third phenotype, pink flowers, when one allele from each genotype is present.

An Example of Co-dominance

ABO blood typing. Blood types A and B are co dominants, and when the genotypes are crossed they create the blood type AB.

Test Crosses

- Cross of an unknown dominant genotype with a homozygous recessive.

- F1 shows genotype of the unknown dominant parent.

- If all children dominant = XX. If any children recessive = Xx.

Sex-linked traits

- Always carried on the X chromosome.

- Hemophilia and colorblindness and sex-linked.

Genotype

Set of alleles. Ex; TT, Tt and tt

Phenotype

What I see. Ex. TT= Tall, Tt= Tall, tt= short.

Chromosomes

- Women have two sex chromosomes, XX

- Men have two sex chromosomes, XY

- Humans have 2 sex chromosomes and 44 autosomal chromosomes (44 total).

- X-linked traits show up in males & females.

- Y-linked traits show up only in males.

Non-disjunction

- Failure of homologous chromosomes, or chromatids, to seperate during meiosis.

- Results in reproduction of abnormal chromosome numbers.

- Can be damaging to offspring.

Trisomy

The consequence of non-disjuction, causing 3 chromosomes to appear (where there should be only 2).

Monosomy

The consequence of non-disjuction, causing 1 chromosomes to appear (where there should be 2).

Turner's Syndrome

Result of having only a single X sex chromosome.

Kleinfelter's Syndrome

Result of having double XXY sex chromosomes.

Karotype

Picture of chromosomes.

Meiosis (Purpose)

The purpose of meiosis is to create haploid cells (gametes - sperm/eggs) and genetic variation.

Meiosis (Stages)

Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II,

Pedigrees

- Are like a family genetic tree

- Show gender, affected persons, non-affected persons and carriers.

Two types of Nucleic Acids

DNA and RNA

3 Structural Units That Form a Nucleic Acid

1. Phosphate

2. 5 carbon sugar (ribose or deoxyribose)

3. Nitrogen base (Purine - A,G or Pyranine - T,C)

Function on DNA

- Blueprint of life

- Never leaves the nucleus

Function of RNA

- Working copy of DNA

- Transcribes information, moves in and out of the nucleus

Structure of DNA

Double-stranded helix

Structure of RNA

Single stranded

Three types of RNA

1. mRNA

2. tRNA

3. rRNA

mRNA Description

- Messenger RNA

- goes into the nucleus and transcribes DNA code

tRNA Description

- Transfer RNA

- Translates mRNA to build proteins

rRNA Description

- Ribosomal RNA

Steps of DNA replication

1. DNA untwists

2. Weak hydrogen bonds break

3. DNA unzips

4. New nucleotides come in and pair up with the original bases.

5. New strands retwist to form the double helix structure.

Steps of Protein Synthesis

1. Transcription occurs, DNA is transcribed to RNA.

2. mRNA leaves the nucleus and travels to structures in the cytoplasm called ribosomes.

3. tRNA reads mRNA codons and brings amino acids to mRNA on ribosome - this is called translation.

Deletion (Mutation)

All or part of the chromosome is lost. Has affects on the amino acid sequence.

Insertion (Mutation)

A base is inserted. Has affects on the amino acid sequence.

Substitution (Mutation)

One base is substituted for another.

Missense Mutation

When a substitution changes the amino acid seuqence.

Silent Mutation

When a substitution does not change the amino acid sequence.

Nonsense Mutation

When a substitution changes the amino acid to a "stop".

Organelles in a eukaryotic cell (plant & animal)

- Nucleus

- Nucleolus

- Mitochondria

- Ribosomes

- Golgi Body

- Endoplasmic Reticulum

- Cytoplasm

- Cell Membrane

- Vacuole

- Lysosomes

Organelles found only in plant cells

1. Cell Wall

2. Chloroplasts

Function of Nucleus

Control center for all cell activity.

Function of Nucleolus

Takes part in protein production. Home to DNA & chromosomes

Function of Mitochondria

"Power house" of the cell. Provides energy. Cite of cellular respiration.

Function of Ribosomes

Site of protein synthesis.

Function of Gogli Body

Protein processing & packaging site.

Function of Endoplasmic Reticulum

Transports proteins & lipids (Pathway)

.Function of Cytoplasm

Gel-like substance, holds everything outside the nucleus.

Function of Cell Membrane

Selectively permeable barrier, some substances can enter.

Function of Vacuole

(Ziploc) Serves as a storage site for certain cell products.

Function of Lysosomes

Digests waste & worn-out organelles.

Function of Cell Wall

Protective barrier, impermeable membrane.

Function of Chloroplasts

Photosynthesis converts energy from sun to sugar. Site of photosynthesis.

Passive Transport

- Does not use energy.

- Includes Simple, Facilitated and Osmosis Diffusion.

Active Transport

- Uses energy.

- Includes Protein pumps, endocytosis, exocytosis.

Simple Diffusion

Diffusion of simple ions from a high to low concentration.

Facilitated Diffusion

Diffusion of larger molecules through the protein channel.

Osmosis Diffusion

Diffusion on water from a high to low concentration. Hypotonic.

Protein Pumps

Act as pumps to move molecules against the concentration gradient.

Endocytosis

The cell membrane moves to engulf material.

Exocytosis

The call membrane moves to release material.

Hypertonic Solution

- More solutes in the solution than in the cell.

- Water moves out of the cell causing it to shrivel up.

Isotonic Solution

- Equal amounts of solute in the solution and cell.

- Cell maintains homeostasis.

Hypotonic Solution

- Less solutes in the solution than in the cell.

- Water flows into the cell causing it to expand.

Pinocytosis

Moving LIQUIDS in or out of the cell through endocytosis or exocytosis.

Phagocytosis

Moving SOLIDS in or out of the cell through endocytosis or exocytosis.

First Step in Cellular Respiration ; Glycolysis

- The breakdown of glucose

- To break down glucose means you need to break some of the bonds. This means electrons are lost, so glucose is being oxidized.

- This process require 2 ATP

- This breaks down glucose into two 3-carbon compounds that are phosphorylated (phosphorylation means phosphate molecule has been added).

- NAD+ is an electron carrier molecule that can pick up electrons. Once electrons have been picked up, this forms NADH.

- 4 ATP molecules are gained, meaning the net gain of ATP for the cell i only 2 ATP.

- The end product is pyruvate (Pyruvic acid)

- Occurs in the cytoplasm of the cell.

Second Step in Cellular Respiration ; Kreb's Cycle

- Aerobic Respiration (requires oxygen) takes place in the mitochondria.

- Pyruvate is converted into Acetyl CoA by enzyme A.

- This goes through a cycle that removes carbon atoms and electrons.

- Eventually oxaloacetic acid is formed again and can be reused in the cycle.

- The removed carbon atoms become CO2.

- The removed electrons are picked up by NAD+ and FAD+. When these combine with electrons they become NADH and FADH2.

- Every NADH molecule can be used to make 3 ATP.

- Every FADH2 molecule can be used to make 2 ATP.

- This step makes the most energy, 36 ATP per glucose molecule.

Second Step in Cellular Respiration if oxygen is NOT present ; Fermentation

- The purpose of fermentation is to allow glycolysis to continue.

- To keep glycolysis going, the NADH have to become oxidized (they need to lose the electrons they picked up during glycolysis).

- Fermentation occurs in the cytoplasm.

Photosynthesis

- Converts light energy into chemical energy (carbs).

- Occurs in two stages.

First Stage of Photosynthesis: Light Dependent Reaction

- LIght is absorbed by chlorophyll pigments in the chloroplast.

- In photosystem I, the electrons join with NADP+ and H+ and make NADH.

- In photosystem II, the electrons move through the electron transaport system which will make ATP.

Second Stage of Photosynthesis: Light Independent Reaction

- Invovles a series of reactionsin a biochemical pathway called the Calvin Cycle.

- Requires energy. This energy comes from the ATP and NADPH that was made in PSI and PSII in the light depedent reaction.

Chemical equation for Cellular Respiration

C6H12O6 + 6O2 ---> 6H2O + 6CO2 + energy

Chemical equation for Photosynthesis

6H2O + 6CO2 +light energy ----> C6H12O6 + 6O2

Difference between eukaryotic and prokaryotic cells

Eukaryotic cells have a nucleus as well as many other organelles that prokaryotic cells do not have. Prokaryotic cells do not have a nucleus, therefore their genetic material is membrane bound.