Evolution

Question 1

evolution defined

Answer 1

genetic variations in a line of descent over a certain period
change in inherited characteristics of biological populations over time

Question 2

Genetic evidence

Answer 2

humans share a common ancestor with different life forms on earth
the fundamental idea of evolution rests upon shared ancestry

Question 3

Processes that promote evolution

Answer 3

natural selection
adaptation
genetic drift

Question 4

Speciation

Answer 4

occur when a population cannot interbreed successfully due to acquisition of many genetic differences thus making them 2 different species

Question 5

Natural Selection

Answer 5

idea was proposed by Charles Darwin
defined as the ability to survive and reproduce due to differences in phenotype
For example, it believes that individuals that are better adapted to their environment are more likely to survive and reproduce
A practical example would be the dark peppered moths were more likely to survive and reproduce during industrial Britain as soot covered the trees thus camouflaging them against predators thus the amount of bright coloured moths depleted

Question 6

Genetic Drift

Answer 6

also known as allelic drift
defined as change in the frequency of an existing allele in different generations due to chance
An example of this is having a larger proportion of brown rabbits in comparison to white ones because of the possibility
of it being hunted due to its light colour
This process may result in the loss of beneficial alleles or lead
to harmful allele fixation as the changes in genetic frequency occurs due to chance unlike natural selection.

Question 7

Adaptation

Answer 7

aids evolution
seen as changes that make an animal better suited for the environment
For example horse teeth have adapted over time for the purpose of grinding grass. Another example is the adaptation of E.coli to utilize citric acid as a nutrient in long term lab experiments.
During evolution, some structures may lose their original function and become vestigial structures.
Humans have a few vestigial structures such as wisdom teeth, coccyx, and vermiform appendix.
Other vestigial structures in other species include wings in flightless birds, sexual traits in organisms that use asexual reproduction.

Question 8

Extinction

Answer 8

defined as the disappearance of an entire species
not an unusual event as it’s part of the evolutionary process
every species fate is to eventually become extinct.
may occur due to competition between species, inability to adapt to their ever evolving environment.
Human activities such as hunting, global warming are the primary causes of extinction.
notion is proved by palaeontology which is the study of fossils

Question 9

fossils

Answer 9

preserved remains of a once living organism which is usually obtained by digging.
300, 000 years ago the earliest fossils of Homo sapiens were found in Africa.

Question 10

Homo Sapiens

Answer 10

species of highly intelligent primates
they are the still living subtribe of Hominina together with chimpanzees, gorillas and orangutans.
erect posture, high manual dexterity, complex language use, walking on twos and tool use in comparison to other animals.

Question 11

Homo Sapiens characterized

Answer 11

erect posture
high manual dexterity
complex language use
walking on twos and tool use in comparison to other animals.

Question 12

Homo sapiens originate

Answer 12

homo Neanderthals which in turn arose from Homo erectus

Question 13

Modern Darwinism

Answer 13

Assimilating Darwin’s theory of natural selection with Gregor Mendel’s theory of genetics
it’s the belief that the variations that bring about selection are based on genes and genetic mutations.

Question 14

Population

Answer 14

group of individuals of the same species who procreate together

Question 15

Global warming

Answer 15

increase in greenhouse gases (CO2, CH4, N2O, ozone, water vapor) leading to an increase in the Earth’s atmospheric temperature

Question 16

Species

Answer 16

group of animals that can reproduce with each other producing fertile offspring

Question 17

Common ancestor

Answer 17

2 or more descendants having an ancestor in common

Question 18

Directional natural selection

Answer 18

environmental changes that can shift a population’s genetic variation towards a new phenotype

Question 19

Disruptive natural selection

Answer 19

natural selection choosing extreme phenotypes that are beneficial

Question 20

Stabilising natural selection

Answer 20

type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value

Question 21

Allele

Answer 21

variants of a gene

Question 22

E. coli

Answer 22

bacteria known to cause a vast range of conditions (diarrhea, urinary tract infections etc

Question 22

Primates

Answer 22

any member of the biological order Primates, the group that contains all the species commonly related to the lemurs, monkeys, and apes, with the latter category including humans

Question 23

Manual dexterity

Answer 23

ability to use hands in a skilful manner, precise and grasping movements

Question 24

Homo Neanderthal’s

Answer 24

Species of primitive human beings that lived between 28,000 and 300,000 years ago

Question 25

Homo erectus

Answer 25

extinct species that gave rise to humans whose teeth were larger and brain was smaller

Question 26

Antibiotic resistance

Answer 26

inability for an antibiotic to kill or inhibit bacteria due to development of evading mechanisms possible via newly acquired genes, adaptation and evolution

Question 27

Antigenic drift

Answer 27

random mutations of surface antigens thereby medication and vaccines may be inadequate in tackling the microbe