Biology 621 Final Exam Review

Chapter 12 -The Nervous System

Central Nervous System (CNS)

increase pulse, blood pressue

dilate pupils, liberate glucose

decrease digestive and urinary systems

prepares the body for emergency

sympathetic nervous system parasympathetic nervous system

autonomic pathways somatic pathways

motor pathways sensory pathways

Peripheral Nervous System

Nervous System

Neuron Structure

Dendrites (receive impulse)

Cell Body (metabolic

functions and “decisions”)

Axon (carries impulse Away from

cell body toward target)

Schwann Cell (Insulates,

protects, nourishes)

Node of Ranvier (between

Schwann cells; place for signal to jump)

Synaptic Terminal (signal

converted to chemical)

The nerve impulse-know the details!

The Synapse

• The axon ends with a synaptic terminal

• Impulses must “jump” across these gaps (synaptic gaps)

• Explain the process

• Neuromuscular junction

Brain structures and functions

Chapter 13

• Endocrine System

• Types of hormones

• Hormone regulation

• Human endocrine glands and hormones (pancreas, adrenal gland, pituitary, thyroid, parathyroid, gonads, pineal, thymus)

Hormone Regulation

A – 2nd messenger model (protein) B – 1 messenger (steroid)

Chapter 14

• Asexual reproduction (Binary fission, Spore formation, Budding, Regeneration)

• Mitosis

•Know the differences in cytokinesis between animal and plant cells

Meiosis- know the 4 stages of meiosis 1

1st Meiotic division produces:2 haploid cells with double stranded chromosomes

2nd Meiotic division produces:4 haploid cells with single stranded chromosomes

Ovarian cycle

Ovarian

hormone

cycle

Menstrual

(uterine)

cycle

Days: 0 7 14 28

Menstral flow

phase

Proliferative

phaseSecretory phase

menstruation

Follicle growth Ovulation

Corpus luteum

degeneration

FEMALE REPRODUCTIVE CYCLE

LH

FSH

Estrogens

Progestins

Estrogen & Progesterone Levels

FSH & LH Levels

Uterine Lining Growth

Chapter 15-Reproduction

Cleavage

• The series of divisions the zygote begins after fertilization

• divides by mitosis (number of cells doubles at each division)

• no growth of cells occurs, instead each division decreases cell size until cells of the embryo are reduced to size of adult organism’s cells

• Morula - solid ball of cells early in the division which goes on to form the Blastula - a hollow sphere filled with fluid. Cavity is called the blastocoel

Gastrulation• Occurs when the blastula reaches

several hundred cells• cells on one side of the blastula

move inward to form a 2-layered embryo called the gastrula

• the opening created is called the blastopore (in humans & vertebrates → this becomes the anus)

• Three sections of the gastrula:• Ectoderm - outer layer of cells• Endoderm - inner layer of cells• Mesoderm - third layer of cells

formed between the ectoderm & endoderm

Chorion

• outermost membrane

• lines the inside of the shell and surrounds the embryo (becomes the placenta in humans)

• aids in exchange of gases with environment

Placenta formation animation

• O2 and CO2 are exchanged through the blood

• vessels of the allantois (becomes the umbilical cord in humans in the 5th week of development)

• metabolic wastes are also collected in the allantois.

Allantois

• Amnion: fluid-filled sac that surrounds the embryo

• amniotic fluid in the sac provides a watery environment for the embryo and acts as a cushion to protect it from shock.

Amnion

• Yolk sac: membrane that surrounds the yolk

• blood vessels carry food from the sac to the developing embryo (this disappears in humans after the development of the placenta)

Yolk Sac

Genetics

• Genetic vocabulary

• Genetics Problems:– Monohybrid crosses, dihybrid crosses, multiple alleles,

sex linked traits, incomplete dominance and codominance

• Mendel’s Laws: – Law of Segregation

– Law of Independent Assortment

– Principle of Dominance

Other scientists: Sutton & Boveri, Thomas Morgan

DNA StructureBasic structure of DNA is a sugar-phosphate backbone

with 1 of the 4 nitrogenous bases. This structure is called a nucleotide.

Backbone Base

• RNA vs DNA Scientists

Replication

Before replication, the parent DNA molecule has 2 complementary strands

First the 2 strands separate (held together by weak H2

bonds)

Each “old” strand serves as a template to determine the order of the nucleotides in the new strand (must be complementary)

Nucleotides are connected to form the backbone; now have 2 identical DNA molecules.

TRANSCRIPTION

Translation of mRNA into proteins

a. The mRNA attaches to the ribosomeb. The initiator site is read (AUG)c. The t-RNA molecules transport amino acids to the ribosome according to the sequence of bases on the mRNAd. The protein molecule is built with one amino acid after another being added to the polypeptide chain. This process is called elongation.e. At the end of the m-RNA strand is a stop/terminator codon which ends the processf. The protein molecule is now released from the ribosome and is transported wherever it is needed.

Factors affecting transcription and translation

GENE MUTATIONS

• POINT MUTATIONS; 2 Groups:

• 1. Substitution (ex. GGTAT to GGAAT)

can be silent, mis-sense, or nonsense mutations.

Missense mutation

2. FRAMESHIFT

• 3 KINDS of Chromosomal mutations:

1) STRUCTURAL CHANGES: (TRANSLOCATION, INVERSION, ADDITION, DELETION)

2) NONDISJUNCTION

3) POLYPLOIDY

• Mutagens

• Causes of mutations

Chapter 18

• Detecting and treating genetic disorders

• Common occurring genetic disorders

• Difficulties in studying human heredity

DNA Amplification:1. Cloning with bacterial vectors

2. Polymerase Chain Reaction

Genetic Engineering Tools:Restriction enzymes, gel electrophoresis, PCR

GENE SPLICING

Gene Therapy

Cloning 101

• GMO’s & GMF’s

• Pros and cons

History of Evolutionary Thought

Hebert Spencer

1820 - 1903

Proposed concept of the

‘survival of the fittest’

Erasmus Darwin

1731 - 1802

Charles Darwin's grandfather

and probably an important

influence in developing his

thoughts on evolution.

John Baptiste de Lamarck

1744 - 1829

First to publish a reasoned theory

of evolution. Proposed idea of

use and disuse and inheritance of

acquired characteristics.

Rev. Thomas Malthus

1766 - 1834

Wrote: ‘An Essay on the

Principles of Population’,

attempting to justify the

squalid conditions of the

poor.

Charles Lyell

1797 - 1875

Major influence on Darwin.

Lyell’s work ‘Principles of Geology’

proposed that the earth is very old.

Julian Huxley 1887-1975

Ernst Mayr 1904-2005

T. Dobzhansky 1900-1975

Collaborated to formulate the modern

theory of evolution, incorporating

developments in genetics,

paleontology and other branches of

biology.

The New Synthesis

Neo-Darwinism: The version of Darwin’s

theory refined and developed in the light of

modern biological knowledge (especially

genetics) in the mid-20th century

R.A. Fisher 1890-1962

J.B.S. Haldane 1898-1964

Sewall Wright1889-1988

Founding of population genetics and

mathematical aspects of evolution and genetics.

Alfred Russel Wallace

1823 - 1913

‘Theory of Natural Selection’

Charles Darwin

1809 - 1882

‘Theory of Evolution

by Natural Selection’

Gregor Mendel

1822 - 1884

Developed the

fundamentals of the genetic

basis of inheritance.August Weismann

1834 - 1914

Proposed chromosomes as the

basis of heredity, demolishing the

theory that acquired

characteristics could be inherited.

Summary of Darwin’s Theory

1. Organisms differ; variation is inherited

2. Organisms produce more offspring that survive

3. Organisms compete for resources

4. Organisms with advantages survive to pass those advantages to their children

5. Species alive today are descended with modifications from common ancestors

Section 19.3 – Evidence for Evolution

1. Fossil Record – fossils reveal kind of organisms that were alive in past & similarities/differences to species living today.

– Chronological

– Not all species are found in fossil records (i.e. new species have evolved)

2. Geographic Distribution of Living Species

• Animals on islands have evolved from mainland migrants

• Populations adapt over time to adjust to the environmental conditions of their new home.

• Example: lemurs only found on island of Madagascar (once part of African continent), but were originally from Africa. Monkeys took over the lemur niche in Africa but could not reach the island.

3. Homologous Body structures

• Body parts in different species that have the same evolutionary origin, but have different structures and functions (ex. Wing & arm bones)

• Allow biologists to trace the evolutionary path of different species, linking them up in the larger evolutionary tree that links all life back to a common ancestor

4. Similarities in Embryology

• Similarities between embryos in related groups (ex. Vertebrates all go through gill pouch stage) point to a common ancestral origin.

5. Heredity

• Variations in populations can arise by :

– Mutations

– Genetic shift

Molecular biology

• Evolutionary relationships among species are reflected in their DNA & proteins

• 2 species with similar patterns of DNA indicates these sequences must have been inherited from a common ancestor.

• All eukaryotic cells have RNA, DNA, ribosomes, same 20 amino acids