Week 1_ Biosphere & Taxonomy, Evolution, Viruses

Question 1

Taxonomy

Answer 1

The ordering and naming of organisms
Originally published by Carolus Linnaeus a system of ___ based on resemblances and two key features of his system remain useful today:
i. each species has two-part name (binomial)
ii. Species are organized hierarchically into broader groups

Question 2

Binomial System

Answer 2

First part of the name is the Genus, second part called the specific name, is unique for each species within the genus.

Question 3

Hierarchical Classification

Answer 3

A taxonomic unit at any level of hierarchy is called a taxon.

Question 4

Domains

Answer 4

Three __ of life

i. Bacteria
ii. Archaea
iii. Eukarya

Question 5

Phylogeny

Answer 5

The evolutionary relationships between organisms is shown as branching___ trees

Question 6

Dichotomies

Answer 6

Depicted as a series of two-way branching points

Question 7

Polytomy

Answer 7

Branch into Three, things are unresolved, don’t quite know at what point what splits happen.

Question 8

Shared Ancestral Characteristics

Answer 8

A character that originated in an ancestor of the taxon. Eg. Vertebral column shared by all vertebrates

A character can be both ancestral and derived, depending on the context.

Question 9

Derived Character

Answer 9

An evolutionary novelty unique to a particular clade.
Eg. Hair is unique to the mammalian clade in the vertebrates.

A character can be both ancestral and derived, depending on the context.

Question 10

Evolution

Answer 10

Process by which the genetic composition of a population over time.

Question 11

What are the causes/ mechanisms of evolution?

Answer 11

Natural Selection

Genetic Drift Gene Flow

Question 12

Population

Answer 12

Smallest unit that can evolve

Question 13

Natural Selection

Answer 13

___ provided a mechanism for evolutionary change. The product of ___ is the increasing adaptation of organisms to their environment - “adapted for”
If an environment changes, ____ may result in adaptation to the new conditions, sometimes giving rise to a new species in the process.

Question 14

Requirements for Natural Selection to occur

Answer 14

i. Genetic variation in populations
ii. Characteristics must be inherited by offspring
iii. Variation lead to differential reproductive success in that environment.

Question 15

Sources of genetic variation include….

Answer 15

i. Existing variation
ii. Meiosis/ Fertilization
iii. Mutation

Question 16

An orange grower discovered that most of his trees were infested with destructive mites. He sprayed the trees with insecticide, which killed 99% of the mites. Five weeks later, most of the trees were infested again, so he sprayed again using the same insecticide. This time only half of the mites were killed.

Explain why the spray did not work as well the second time, considering the characteristics of evolution by natural selection.

Answer 16

Evolution is the process by which the genetic composition of a population changes over time.
Mechanism: natural selection
It happens when there is a change in the environment (insecticide)
i. Variation in population: Exists. Not all of the mites were killed, 1% of the mites survived.
ii. Characteristics are heritable
iii. Differential reproduction success.