Topic 2 - Life, Diversity; Introduction to Natural Selection

Question 1

Biological diversity

Answer 1

the difference between living things

The variety within and among living species

Question 2

Things that are alive can

Answer 2

Reproduce

Grow

Have functional activity: movement, response to stimuli, metabolism, catabolism, excretion

Adaptation: can change over (evolutionary) time in response to the environment

Question 3

The simplest division

Answer 3

Alive and not alive

Question 4

Examples of things alive and not alive

rock

prion

coral

virus

Answer 4

rock - no

prion - composed of a protein that can fold in multiple ways. One way of folding is transmissible to other proteins. Causes mad cow disease.

a coral is alive. does all 4

A prion does none. It is not alive.

A virus can adapt but cannot do the other 3. It is not considered alive.

Question 5

What are the broadest taxonomic categories

Answer 5

Domains and Kingdoms

Question 6

Each kingdom groups together

Answer 6

all forms of life having certain fundamental characteristics

Question 7

A species is

Answer 7

a group of individuals that regularly breed together

Question 8

How were organisms grouped until about 50 years ago?

Answer 8

Based on observations of behaviour, shape, size etc

Plants = organisms that don’t move and appeared to make their own food

Animals: organisms that could move about and relied on other organisms for food

Question 9

in 1969

Answer 9

Scientist introduced a system of 5 kingdoms, categorized according to cell type and method of obtaining energy

Question 10

Modern taxonomy

Answer 10

Has 3 domains and 6 kingdoms based on molecular characteristics

Question 11

Eukarya vs Prokarya

Answer 11

Eukarya = single or multicelllular and have membrane bound organelles

Prokarya = single celled and dont have membrane bound organelles

Question 12

3 domains

What are prokarya

Answer 12

(1) Eukarya
(2) Bacteria
(3) Archaea

Prokarya - Bacteria and Archea (archea are prokaryotes that are not bacteria)

Question 13

6 kingdoms

Answer 13

Animals
Plants
Fungi
Protista

ALL EUKARYOTES

Bacteria
Archaea

PROKARYOTES

Question 14

Bacteria & Archaea

Answer 14

Single celled, free living or colonial

Cells are small, do not have membrane bound organelles (nucleus, mitochondria or chloroplasts)

Numerous - more bacteria in one mouth than all humans that ever existed

Question 15

Eukarya - protists

Answer 15

Mostly single celled
Diversity of lifestyles
Plant-like, fungi-like and animal-like types

Question 16

Eukarya - plants

Answer 16

Multicellular
Make their own food
Largely stationary

Question 17

Eukarya - fungi

Answer 17

Multicellular
Rely on other organisms for food- tendrils into substrate
Reproduce by spores

Question 18

Eukarya - Animals

Answer 18

Multicellular
Rely on other organisms for food
Mobile for at least part of the life cycle

Question 19

How are organisms classified?

Answer 19

Start with broad categories with a few fundemental charecteristics

As you mive through the classification, create more specific subcategories

A species is a group that regularly breeds together

Question 20

The tree of life

Answer 20

Based on evolutionary relationships
All life stems from divergence of a single ancestor

Early divergence resulted in major groupings (eg domains) which correspond to divergences which happened very early in lifes history

Minor groupings correspond to more recent divergence

Question 21

The origin of divergence

Answer 21

was due to mutations in DNA and RNA

Question 22

The nucleus first hypothesis of Eukaryote differntiation

Answer 22

The Endosymbiotic Theory. The first eukaryote may have originated from an ancestral prokaryote that had undergone membrane proliferation, compartmentalization of cellular function (into a nucleus, lysosomes, and an endoplasmic reticulum), and the establishment of endosymbiotic relationships with an aerobic prokaryote, and, in some cases, a photosynthetic prokaryote, to form
mitochondria and chloroplasts, respectively.

A prokaryote engulfs a nucleus, then a mitochondria or plants

Question 23

History of Charles Darwin

Answer 23

Born in 1809
Went to med school in Edinburgh and was bored. Was trained in taxidermy by John Edmundstone, a freed slave
After graduation became a collector on the HMS beagle where his voyage was paid for by rich people for the samples he brought back
In the Galapagos islands off Ecuador, he observed many animals including Darwin’s finches

Why were there different kinds of finch on different islands that were similar to, but different from the others and those on the mainland?

Question 24

History of Alfred Russel Wallace

Answer 24

Born in 1823
Always wanted to understand the distribution of species even before she was a collector
Went to the Amazon because his exposure to animals from there in museums had indicated there was a big variety of animals
Was a bad choice- lots of species but not many of each (low abundance). Also hard to collect and dangerous. His bro died of yellow fever there.
Boat nearly sank near Barbados but did not.

Luckily the amazon river is huge and not all species can cross it. Noticed the birds were the same on both sides of the river as they can fly but the monkeys were not.

Decided that natural barriers can separate species and therefore Islands are a good place to study this.

Went to Malaysia
Published a paper on the physical distribution of species
Corresponded with Darwin
Wanted him to read a manuscript on the origin of species abd pass it on to Charles Lyelle of the Linnean society

Question 25

The publication story

Answer 25

We don’t know what happened next.

What happend between Lyelle receiving this and Darwin submitting his own is unclear
Whether Wallace nudged him to finish it faster or gave him additional info he needed we do not know

Both were presented at the same time
Darwin had books worth of thoughts so had clearly been thinking about it

The theory did not make a big splash, took time but became a phenomenon