Chapter 8 and 9: Biodiversity and Evolution

Question 1

Evidence of Evolution include:

Answer 1

• fossil records
• comparative anatomy
• comparative embryology
• comparative biochemistry
• geographical distribution

Question 2

The preserved remains of animals and plants that lived in the past.

Answer 2

Fossils

Question 3

Examples of animals.

Answer 3

• imprints of plant or animal parts on rocks
• animals trapped and frozen in ice
• insects trapped in a hardened plant resin (amber)
• bones preserved in a peat bog (spongy ground with decaying plants, etc.)
• stone casts of mollusks and animal shells
• wood or giant plant parts replaced by minerals

Question 4

Where are most fossils formed?

Answer 4

Most fossils were formed at the bottom of shallow bodies of water, where the remains of dead organisms settled to the bottom and were covered by mud or sand that slowly turned into sedimentary rocks.

Question 5

These are formed in layers stacked on top of another. The oldest fossils were stacked at the bottom, while the most recent ones were stacked on top.

Answer 5

Sedimentary rocks

Question 6

_ provide most important evidence to compare it with using organisms’ structure and all.

Answer 6

layers of sedimentary rocks

Question 7

Through this process, scientists reconstruct complete structure of organisms from past.

Answer 7

Fossil Reconstruction

Question 8

These show that many organisms were very much different from the organisms that exist today. They also show the succession of organisms that is consistent with the stacking of sedimentary rocks from the older to the younger layers.

Answer 8

Fossil records

Question 9

The rate of decay for each element is steady. Scientists use the unit called _ to measure the rate of decay of an radioactive element. The _ of an element is the time it takes for half of the radioactive element to decay. By determining how much of a particular radioactive element (usually uranium) has changed into a stabilized form (usually lead), scientists can approximate the age or rocks or fossils.

Answer 9

half-life

Question 10

One way of approximating the age of rocks or fossils. Radioactive elements in rocks or fossils give off radiation at constant known rate, and gradually transform into different elements until they stabilize into an element that no longer emits radiation.
– igneous and metamorphic rocks –
– static-correlation method –
– method of dating rocks and materials using radioactive act.

Answer 10

Radioactive dating

Question 11

Another method used to date fossils is by _ where most fossils are found. The lowest layers of rocks are the oldest, thus scientists can estimate the age of a fossil by noting its placement in rock layers.

Answer 11

examining sedimentary rocks layers

Question 12

The sedimentary layers are stacked in order of their ages. This is based on the principle known as the _, which states that in a series of sedimentary rock layers, the younger rocks are normally found on top of older rocks.

Answer 12

law of superposition

Question 13

Using fossil records, paleontologists are able to trace and reconstruct the transformation of an organism over a span of time. One example is the proposed evolution of the horse. The _, which has been widely known as _ (dawn horses), appeared about 50 million years ago (mya).

Answer 13

Hyracotherium; Eohippus

Question 14

This provides clues pointing to evolution and common answers. Similar structures evolve.

Answer 14

Comparative Anatomy

Question 15

Structures that are similar in form and origin, but became modified to adapt to different functions. They have the same basic structure and origin.

Answer 15

homologous structures

Question 16

In plants, what are the homologous structures?

Answer 16

leaves, petals, sepals, pistils, stamens

Question 17

Some body parts among different organisms are similar in function, but different in origins. These are?

For examples, the wings of birds, butterflies, and moths are used for flying. Organisms with _ structures may not be closely related.

Answer 17

analogous structures

Question 18

These are assumed to have lost their primordial functions as species of organisms adapted to changes in their environment. While these organs in some groups of organisms may have lost most or all of their original functions, these organs in other groups of organisms may still be useful and functional.

Answer 18

Vestigial organs

Question 19

Humans vestigial structures include:

Answer 19

• appendix
• body hairs
• muscles that move ears
• wisdom teeth

Question 20

This is vestigial, but this organ is a functional structure in herbivores, such as rabbits. It has gradually diminished its function as our ancestors’ diet started to contain less cellulose and food was made more palatable by cooking.

Answer 20

human appendix

Question 21

According to scientists, embryos appear so similar that it is difficult to tell them apart.

Answer 21

Comparative Embryology

Question 22

A German biologist noted distinct similarities in the embryological development of fish, reptiles, birds, and mammals. The early stages of growth in all these vertebrates are marked by pharyngeal pouches and tails.

Answer 22

Karl Ernst von Baer (1792-1876)

Question 23

As the embryos continue to develop, the distinguishing characteristics of each of these species begin to appear. This similarity in the early development of embryos in vertebrates suggests a common ancestry among them.

Answer 23

Comparative Embryology

Question 24

Perhaps, the most convincing evidence of common descent is the _.

Answer 24

biochemistry of cells

Question 25

Organic compounds that are found in all cells.

Answer 25

• proteins
• carbohydrates
• lipids
• nucleic acids

Question 26

This is also a biochemical characteristic common to all organisms.

Answer 26

dependency upon water

Question 27

When did it become possible to analyze the amino acid sequence of proteins?

Answer 27

1970s

Question 28

How is it possible to show evolutionary relationships?

Answer 28

Comparing amino acid sequence of similar proteins from a wide variety of organisms makes it possible to show evolutionary relationships.

For example, the human cytochrome c, a mitochondrial protein that is highly conserved across different species, was found to be identical to that of a chimpanzee and to differ by one amino acid from that of a rhesus monkey. This suggests that our biochemical makeup is more closely related to that of the chimpanzee than to that of the rhesus monkey.

Question 29

What indicates close evolutionary relationship?

Answer 29

Very few differences in the amino acid sequences.

Question 30

Today, this provides better understanding of a common ancestry. The more closely related two organisms are, the more similar their DNA sequences.

Answer 30

direct sequencing of DNA and RNA

Question 31

The _ of living things all over the world also provides clues to how species of organisms have changed through time to adapt to changing environmental conditions. Plants or animals that have similar characteristics can be found distributed in previously adjacent continents. Similarities in traits suggest a possible common descent.

Answer 31

Geographical Distribution

Question 32

Through _ and _, plants or animals have come to inhabit different environments and have evolved along separate lines with different adaptation to their new habitats. Some species of animals, such as whales for example, are adapted to living in water, whereas others, such as dogs and monkeys, are adapted to living on land. Darwin.

Answer 32

migration and isolation

Question 33

Mechanisms of Evolution include/Mechanisms through which evolution could take place:

Answer 33

• mutation
• natural selection
• migration
• genetic drift

Question 34

Changes made in the DNA molecules.

Answer 34

Mutation

Question 35

The process by which organisms with favorable traits suited to an environment have a better chance of surviving or reproducing.

Answer 35

Natural Selection

Question 36

Natural Selection is classified into:

Answer 36

• Stabilizing Selection
• Directional Selection
• Diversifying Selection

Question 37

The movement of one population into a habitat previously occupied by another population.

Answer 37

Migration

Question 38

Changes in the frequency of a gene in a population as a result of chance.

Answer 38

Genetic Drift

Question 39

DNA replication sometimes results in an error or a failure that changes its code. This may also result in a change in inherited characteristics that may be passed on to the next generation. At other times an external environment agent may trigger this change. Changes made in the DNA molecule through any of these ways is called _.

Answer 39

Mutation

Question 40

The process by which organisms with favorable traits or traits suited to an environment, have a better chance of surviving and reproducing than those that are not suited. In other words, organisms with favorable traits have a greater chance of passing on their genes to the next generation.

Answer 40

Natural Selection

Question 41

He observed that reproduction roughly balances with death, illness, accident, and age, and noted the different characteristics even with members of same species — all of these were inherited.
– observable/physical characteristics - many of their variations are because of the inheritance –
He also proposed that offspring whose hierarchy allow them to reproduce and survive well than those less well-adapted (temp., more widespread in subsequent generation). Its idea could change so significantly that a new species can be formed.

Answer 41

Charles Darwin

Question 42

Charles Darwin explained the five causes of evolutionary change, with each explaining how evolution happens:

Answer 42

1. Overpopulation
2. Struggle for Existence
3. Presence of Variation
4. Survival of the Fittest
5. Variations can be transmitted

Question 43

When organisms produce a huge number of offspring that can actually survive, this occurs.

Answer 43

overproduction

Question 44

This idea of the _ (or more accurately, of the fit enough) is at the core of natural selection.

Answer 44

survival of the fittest

Question 45

He independently came up with the idea of natural selection and reinforced the claims of Darwin.

Answer 45

Alfred Russel Wallace (1823-1913)

Question 46

Natural selection and evolution depend on heritable (genetic) variations, which can result from _ or _.

Answer 46

sexual reproduction or mutation

Question 47

The exchange of segments between homologous chromosomes during meiosis.

Answer 47

Crossing-over

Question 48

_, which are spontaneous changes in genetic material, can provide the basis for evolutionary changes.

Answer 48

Mutations

Question 49

A bacterium that causes gonorrhea, a sexually transmitted disease, has rendered it resistant to antibiotics.

Answer 49

Neisseria gonorrhea

Question 50

The three types of natural selection according to their effects on the distribution of phenotypes within a population.

Answer 50

Stabilizing Selection, Directional Selection, Diversifying Selection

Question 51

This occurs in most populations where competition is not too strong. It acts against phenotypic extremes by removing these and stabilizing the species toward intermediate phenotypes.

Answer 51

Stabilizing Selection

Question 52

This results in a population adapting to gradual changes in the environment. The evolution of giraffes from short-necked ancestors to the present long-necked giraffes is a good example. It acts against one extreme phenotype, favoring the other extreme.

Answer 52

Directional Evolution

Question 53

It caused air pollution which killed the lichens and eventually covered the trees with dark, sooty deposits.

Answer 53

Industrial Revolution

Question 54

A rare situation in which environmental conditions favor the development of two extreme phenotypes. It acts against intermediate phenotypes. This results when selective pressures are intense, and competition among individuals within a population favors the two extreme phenotypes. The isolating mechanisms that prevent reproduction between evolving subpopulations include geographical barriers (e.g., mountains and oceans), and different breeding times.

Answer 54

Diversifying Evolution

Question 55

The third process that leads to evolution. The movement of one population of a species into a habitat previously occupied by another population can lead to changes in gene frequency.

Answer 55

Migration

Question 56

This, along with mutation, natural selection, and migration, is one of the mechanisms of evolution. It refers to changes in the frequency of a gene in a population as a result of chance.

Answer 56

Genetic Drift

Question 57

An ethical consideration for preserving biodiversity.

Answer 57

“all life depends on uninterrupted functioning of natural systems that ensure the supply of energy and nutrients, so ecological responsibility among all people is necessary for the survival, security, equity, and dignity of the world’s communities”

Question 58

This includes limiting our consumption of nonrenewable resources to amounts just enough to meet our basic needs. It also includes ensuring that renewable resources are conserved. Taking this will benefit not only the present generation but also the future generations.

Answer 58

Ecological responsibility

Question 59

This in an ecosystem ultimately limits the amount of organic matter that can be produced. It refers to the amount of energy that is transformed through a food chain. Both energy and nutrients are transferred and transformed through the food chain.

Answer 59

Energy flow

Question 60

Most of the energy involved in food chains are lost as _. A rough estimate of only about 10% of the energy at each trophic level is made available to organisms occupying the next trophic level. The remaining 90% is lost as _. This means that top level consumers receive the least amount of energy.

Answer 60

heat energy

Question 61

The ultimate source of energy.

Answer 61

Sun

Question 62

When it comes to the flow of energy in ecosystems, the two types of organisms involved are?

Answer 62

producers and consumers

Question 63

They manufacture their own food by converting energy from the environment into chemical energy.

Answer 63

Producers

Question 64

They depend on other organisms for food.

Answer 64

Consumers

Question 65

Through this metabolic process, consumers are able to obtain energy from the food they eat.

Answer 65

cellular respiration

Question 66

Ultimately, all organisms die and become food for _.

Answer 66

decomposers

Question 67

During _, energy is lost as heat and inorganic nutrients are returned to the soil or water to be used again.

Answer 67

decomposition

Question 68

Life processes require _. It is the ability of matter to do work.

Answer 68

Energy

Question 69

Two pathways by which energy enters an ecosystem.

Answer 69

photosynthetic pathway and a pathway involves heat energy being transferred by air, water currents, or convection to warm up the organisms.

Question 70

Through the photosynthetic pathway, energy is fixed by _, which can synthesize their own food from light energy.

Answer 70

photoautotrophic organisms

Question 71

They make their own food by metabolizing inorganic matter.

Answer 71

chemoautotrophs

Question 72

In every ecosystem, it provides a foundation for life and thus puts a limit on the abundance and diversity of life. This is one of the important processes that sustains ecosystems and reflects the dynamics of life.

Answer 72

flow of energy

Question 73

The process by which a species passes out of _. It is a natural process in our planet’s history. About 90 to 99 percent of all living things that have ever existed on Earth are now extinct. There are countless of species of microorganisms, fungi, plants, and animals that have appeared, survived for a time, and then became extinct.

Answer 73

Extinction

Question 74

In the past 300 million years or so, human activities, such as _, _, _, and _ have greatly increased the rate of extinction at about 40 to 100 species per day.

Answer 74

hunting, illegal logging, infrastructure building, and farming

Question 75

These increase the rate of extinction because they change the environment too quickly for the organisms to adapt.

Answer 75

Human activities

Question 76

When the environment changes for the worse, organisms that have become rare are in danger of becoming extinct and are referred to as _.

Answer 76

endangered species

Question 77

Three concepts of biological diversity or biodiversity.

Answer 77

Habitat diversity, Species diversity, Genetic diversity

Question 78

It refers to the diversity of habitats in a given unit of area.

Answer 78

Habitat diversity

Question 79

It refers to the total number or relative abundance of species.

Answer 79

Species diversity

Question 80

It refers to the total number of genetic characteristics of a specific species, subspecies, or group of species.

Answer 80

Genetic diversity

Question 81

This enables populations to adapt to changing environments. The more variations there are in a population, the more likely it is that population possess genetic characteristics that are better adapted to the environment.

Answer 81

Genetic diversity

Question 82

The study of the factors that influence the size, density, distribution, and growth of a population. It tries to understand and answer how and why population changes over time.

Answer 82

Population ecology

Question 83

It refers to a group of organisms of the same species that live in a particular area.

Answer 83

Population

Question 84

Any factor of the environment that limits the size of a population. Diseases and availability of food, water, and shelter are examples of this.

Answer 84

limiting factor

Question 85

The two most important characteristics of a population.

Answer 85

density and distribution

Question 86

It refers to the number of individuals per unit area or unit volume. It is a measure of population size.

Answer 86

Population density

Question 87

A more exact measure defined as the number of individuals per unit of available space.

Answer 87

Ecological density

Question 88

This, also referred to as population dispersion, is the spatial distribution of individuals of a population.

Answer 88

Population distribution

Question 89

Three general patterns of population distribution.

Answer 89

random dispersion, regular dispersion, clumped or aggregated dispersion

Question 90

Individuals in a population are independent of each other because the habitat conditions are relatively uniform all throughout as in a tropical rainforest. Individuals are neither repelled nor attracted to one another. This is not very common in nature.

Answer 90

Random Dispersion

Question 91

Individuals are about the same distance from one another, often due to competition among individuals in the same population. For example, desert shrubs competing for water often display this type of pattern.

Answer 91

Regular Dispersion

Question 92

Individuals clump together because resources and suitable habitats may be patchy in distribution. This may be due to daily and seasonal variations in weather conditions, or to the organism’s cyclic reproductive patterns. Individuals may also clump together as a social behavior (e.g., seals clump together for breeding purposes and fish swim in large schools as protection against predators).

Answer 92

Clumped or Aggregated Dispersion

Question 93

In 1798, this British scholar who is influential in political economy and demography, wrote a book entitled “An Essay on the Principle of Population”. He became known for his theories on population.

Answer 93

Thomas Robert Malthus

Question 94

According to Malthus, human population has the tendency to increase at a much faster rate than its food supply, which could lead to famine, war, and disease. Several years later, his idea was supported by _, who concluded that the potential of a population to overcome its resources exists in all populations.

Answer 94

Charles Darwin

Question 95

The change in population size is due to the following factors:

Answer 95

birth (natality), death (mortality), immigration, and emigration

Question 96

These factors result in an increase in population.

Answer 96

Birth and immigration

Question 97

These factors result in a decrease in population.

Answer 97

Death and emigration

Question 98

Both the abiotic and biotic factors in the environment affect the population growth rate. Population ecologists have developed two models to describe the growth of populations:

Answer 98

Exponential Growth and Logistic Growth

Question 99

The simplest model of population growth that assumes a constant growth rate. Ecologists refer to this growth model as the “J-shaped population growth form” because the resulting graph looks like letter “J”.

Answer 99

Exponential Growth

Question 100

A more realistic model of population growth where growth rate varies with population size. As a population reaches resource limitations, its growth slows down and stabilizes forming a logistic, sigmoid, or S-shaped graph.

Answer 100

Logistic Growth

Question 101

The maximum population size of the species that the environment can sustain without getting depleted.

Answer 101

carrying capacity

Question 102

Limiting factors in populations can be categorized as:

Answer 102

density-dependent or density-independent factors

Question 103

These affect a population when it reaches a certain density. This includes competition, predation, diseases, parasitism, crowding, and stress factors.

Answer 103

Density-dependent factors