1. Theories Of Evolution

Question 1

Define Darwin’s theory

Answer 1

His theory believed plants and animals evolved over time through a process of natural selection which ensured ‘survival of the fittest’

Question 2

What observations led to Darwin’s theory?

Answer 2

1. Members of a population in the same species vary in their traits
2. Traits can be inherited, or passed from parent to offspring
3. Populations are capable of producing more offspring than the environment can support
4. Due to lack of food or other resources, many off the offspring do not survive

Question 3

Define Lamark’s theory

Answer 3

Stipulated that a characteristic which is used more and more by organisms can be achieved and becomes a stronger trait

Question 4

Observations lamark saw

Answer 4

Giraffes did have normal necks but food was higher so he hypothesised that they needed a taller neck so they got one and evolved and passed it onto offspring

Question 5

Define macro-evolution

Answer 5

Major evolutionary change with regards to the whole taxonomic group over long periods of time

Question 6

Define micro-evolution

Answer 6

Evolutionary change within a species or a small group, especially in a short period of time

Question 7

Natural selection?

Answer 7

Traits in different forms of life that better enable them to adapt to specific environmental pressures

Eg.
Predators, climate change, access to food and makes

Some traits will change to better enable access to these things and some will thrive and reproduce ensuring the survival of some of these traits in the future

Question 8

Fossil record?

Answer 8

Term used to refer to the total number of fossils that have been discovered as well as the total information derived from them

Question 9

Relative dating?

Answer 9

Used to arrange geological events and the rocks they leave behind in a sequence.

Question 10

Absolute dating?

Answer 10

The determination of an object with reference to specific time scale, such as a fixed calendar or in years before present (BP), based on measurable physical or chemical qualities or associations with written records

Question 11

Homologous structures

Answer 11

Each cell has two sets of each chromosome
One pair is derived from mother and other from father
In homologous pair gave the same genes but possibly different alleles

Question 12

Homologous structure (homology)

Answer 12

The existence of shared ancestry between a pair of structures or genes in a different taxa

For example, the forelimbs of an invertebrate and wings of a bat share the same ancestral
tetrapod structure