Species & Speciation
Is a brown pelican a species? Yes or No.
Yes
What is natural selection?
The process in which organisms with certain
inherited characteristics have an increased chance of
survival and therefore reproduce, passing on these
favourable traits to their offspring.
Is genetic engineering a type of natural selection or is it a type of artificial selection?
Artificial Selection.
Draw a chromosome and label the middle part.
Teacher will assess (centromere)
How is the biological special concept different from the morphological species concept?
Biological species concept:
A species is a group of organisms that can
interbreed in nature to produce fertile offspring.
Morphological Species concept:
A species is a group of organisms that have
common distinctive features of morphology (physical
appearance), physiology, anatomy and behavior.
How are Darwin's finches an evidence of natural selection?
Beaks of birds evolved to suit different food sources
Thus improves their long-term survival in different
environments.
What is genetic engineering?
Techniques involved in changing the traits of an organism by inserting genetic material from another organism.
Draw an example of a Punnet Square and an example of a Pedigree Chart.
Teacher will assess.
What are two difficulties/limitations of the biological species concept?
Difficulties and Limitations:
1. Cannot be applied to fossils (preserved remains of dead
organisms cannot breed.
2. Cannot be applied to asexual organisms (no mating).
3. Not easy to observe mating behavior in the wild and check
offspring for fertility.
Explain one scenario that shows a clear depiction of natural selection (has to be an original scenario).
Teacher will assess.
Who was the first cloned animal?
Dolly the sheep (1996)
Give an example of an allele. Label the phenotype and state the genotype. State the dominant and recessive genes.
e.g. Hair color; black hair: BB/Bb (dominant); brown hair: bb (recessive)
Female horse and male donkey = mule
Give one more example of unrelated species mating (ensure you correctly identify which is the male and which is the female).
The liger is a hybrid offspring of a male lion and a female tiger.
tigon: a male tiger with a female lion.
List 4 evidence of Natural Selection and explain how natural selection leads to evolution.
Darwin’s Finches
• Peppered Moths
• Antibiotic resistant bacteria
• Pesticide resistance
• Flower Coloration
• Caribbean Lizards
Theory of evolution: “All species have evolved
from common ancestors through gradual
change.”
Over a period of time organisms change to
adapt to their environment.
What are three ways how humans apply/use genetic engineering?
- Commercial production of medicine e.g. insulin, other hormones, antibiotics, vaccines, enzymes
• Disease Treatment e.g. gene therapy
• Agriculture/Food production e.g. transgenic crops & animals (GMOs) with improved nutrients & resistance to pests/disease
• Reproductive Cloning- Creating an identical copy of an organism e.g. 1st cloned animal, Dolly the sheep (1996)
• Therapeutic Cloning- cloning cells from a human for use in medicine and transplants (still in research phase) e.g. creating a new liver toreplace a diseased one
• DNA testing e.g. paternity tests
Explain and provide an example of codominance, complete dominance and incomplete dominance.
co - blood types - coexist...no dominance such as A and B
complete - hair color, albinism, tongue rolling
incomplete - mixing of traits such as pink flower from red and white flower...neither allele is dominant over the other
Name the two types of speciation and explain the difference between them.
Sympatric Speciation: A new
species form from a single
parent population while
inhabiting the same geographic
region. Developed from
ecological/behavioral
differences.
• Allopatric Speciation: A new
species form from physical
separation of the parent
population
Natural Selection
Artificial Selection
1. Explain each
2. How are they different from each other
3. List one example of artificial selection and two benefits.
Natural selection is the process by which a population remains well adapted to its changing environment.
Artificial selection is the process in which humans deliberately isolate populations and selectively breed individuals with desirable characteristics to suit their needs.
In artificial selection humans select and favor
specific traits. E.g. plant & animal breeding
- Farmers can improve productivity of their
crops and animals
In natural selection the environment acts as a
sieve through which only certain variations
can pass.
Explain one of these applications of genetic engineering:
1. What is it?
2. Uses
3. Benefits
4. Why is it considered genetic engineering?
Transgenic Rice, Genetically modified crops, DNA testing, Human Insulin Production or Gene Therapy.
Teacher will assess.
If the following mates, what will be the outcome?
Heterozygous x Homozygous recessive=
2 Heterozygotes (Hh)
2 Homozygous recessive (hh)