Natural Selection ,Variation & Adaptation (1)

BIOLOGY

What makes
you different in
your family or
from your
classmates ?

Name : _____________________________
Group : _____________________________
This workbook is intended to be used in class along
with your notebook
Teacher : Wilson-James

Success Criteria - Natural Selection , Variation & Adaptation

CIE Priority Standards:
9Bv2 Understand that organisms inherit characteristics from their parents through genetic material that

is carried in the nuclei of the cell
9Bv3 Describe how selective breeding can lead to new varieties

9Bv4 Discuss the work of Darwin in developing the scientific theory of natural selection

9Be1 Explain ways in which living things are adapted to their habitats

Complete the “ I can Statements “check boxes with date ( Y/N/ U-for
undecided )

Success Criteria Date Date Date

“ I CAN “

Explain that characteristics are passed on in genes and the
genetic material is stored in the nucleus of the cell from one
generation to another .

● Distinguish between traits that can be inherited, acquired
and traits that can be both inherited and acquired

Describe how selective breeding can produce new varieties
and desired traits (ie sweeter fruit, bigger eggs, a desired
flower, etc.)

Describe Charles Darwin’s theory of natural selection

Predict phenotypes and genotypes in given scenarios

Suggest changes in population characteristics in response to
known environmental changes

Discuss Mendel’s Theory and draw diagrams of second and
third generation pea plants crossed with varying traits

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SECTION A

Complete a “ Do Now” task daily or as directed by your teacher

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SECTION B- What is Variation?

Activity 1- Find someone in your class that shares the same features as you do
and complete the chart below.

Who did you find that has all the same characteristics as you do ___________

Why do you think that everyone is so different ?.
_______________________________________________________________

How would you categorize the different features discovered in your class ?

Category 1_______________________ Category 2_____________________

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Genotype- A combination of alleles used to determine characteristics
What do these letters mean ?

They represent the alleles of traits
and are referred to as genotypes- They are always in pairs

Upper case letter means genes is Dominant
Lower case letter means genes is recessive

Phenotypes

● phenotypes are physical descriptions using words that describe genotypes
● so BB and Bb are brown eyes and bb is blue eyes

Your Turn
What is your genotype for your hair colour ?
_____________________________________
What is your phenotype ?__________________

What is your genotype for your skin colour ?

What is your phenotype

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Words you should be able to recognize and recall:

Inherited traits gametes alleles

Traits acquired traits genetic

Adaptation chromosomes DNA

Habitat genes natural selection

thrive selective breeding

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Edpuzzle Time - This is a quiz associated with the video
Video #1- WHat is variation
Scan the code or click on the link https://tinyurl.com/yyoxph6v

Watch the video and answer the questions as you go along. If you
are reading this online Hover over the document.

Drawing Punnett squares

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Understanding Variation
Independent activity

Collect a shape from your
teacher and all the additions .
Use to materials provided to
create a face to your liking .
Use the venn diagram below to
compare another image of the
same species

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Drawing Punnett squares
Edpuzzle Time - This is a video on how to draw punnet aquares
Scan the code or click on the link https://youtu.be/prkHKjfUmMs

ou are reading this online Hover over the document.

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Lesson Topic: Types of Variation

Class notes- annotate in your notebooks using Cornell note taking style

Copy the table in your Phenotypic Genetic
notebook using a ruler. Continuous Discontinuous
Use the notes below to
write a brief description
of each type of variation

TOPIC: Types of Variation

● Variation is defined as differences between individuals of the same species
● Phenotypic variation is the difference in features between individuals of the same species
● Some of these differences are caused by differences in genes, which is genetic variation
● Phenotypic variation can be divided into two types depending on how you are able to group the

measurements:
○ Continuous Variation is when there are very many small degrees of difference for a particular
characteristic between individuals and they are arranged in order and can usually be measured
on a scale
○ Examples include height, mass, finger length etc. where there can be many ‘inbetween’ groups
○ Discontinuous Variation is when there are distinct differences for a characteristic
○ For example, people are either blood group A, B, AB or O; are either male or female; can either
roll their tongue or not – there are no ‘inbetweens’

When graphs of these data are plotted, continuous variation gives smooth bell curves (a result of all
the small degrees of difference), whereas discontinuous gives a ‘step – like’ shape

Variation Graphs - Can you spot them

When graphs of these data are plotted, continuous variation gives smooth bell curves (a result of all
the small degrees of difference), whereas discontinuous gives a ‘step – like’ shape

Continuous variation Discontinuous variation

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Factors that can affect variation - Cornell notes

Environmental Variation

● Characteristics of all species can be affected by environmental factors such as climate, diet,
accidents, culture and lifestyle

● In this instance ‘environmental’ simply means ‘outside of the organism’ and so can include
factors like climate, diet, culture, lifestyle and accidents during lifetime

● Examples include:
○ An accident may lead to scarring on the body
○ Eating too much and not leading an active lifestyle will cause weight gain
○ Being raised in a certain country will cause you to speak a certain language with a
certain accent
○ A plant in the shade of a big tree will grow taller to reach more light

Genetic and Environmental Causes

● Discontinuous variation is usually caused by genetic variation alone
● Continuous features often vary because of a combination of genetic and environmental

causes, for example:
○ tall parents will pass genes to their children for height
○ their children have the genetic potential to also be tall
○ however if their diet is poor then they will not grow very well
○ therefore their environment also has an impact on their height

● Another way of looking at this is that although genes decide what characteristics we inherit,
the surrounding environment will affect how these inherited characteristics develop

https://edpuzzle.com/media/5f934463f75b444096d8c6b0

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On Your own- formative assessment

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Find the different variations of species in the
paragraph, and highlight to show what caused the

variation

On a visit to the zoo, a student saw lots of different
types of big cat. In the pride of lions the males had a
mane, but the females didn't. There was one lion
with big scar on its face. Some of the lions were a
little overweight. All the tigers had stripes, whilst
the leopards had spots. Some of the leopards were
larger than others.

Key
Inherited – Characteristics caused by genes found in the nucleus of all
cells. Can be passed on from parents to offspring.
Environmental – Characteristics caused by influences in the environment.
Cannot be passed on from parents to offspring.
Both – Some characteristics can be influences by both genes and the
environment. Highlight these in a third colour.

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Lesson Topic : Natural Selection and Evolution - Paraphrase using
Cornell notes
Instructions: Rule up your notebook for Cornell notes. Read the section below and complete the cornell

notepage in your books .

Topic: Natural Selection
Essential Question : What is the role of natural selection in the survival of a
species?
Question 1- What is Natural Selection ?
Question 2- Describe what causes competition
Question 3- Who is the scientist responsible for the theory of natural selection?

Natural Selection

● In any environment, the individuals that have the best adaptive features are the ones most likely to
survive and reproduce

● This results in natural selection:
● Individuals in a species show a range of variation caused by differences in genes
● When organisms reproduce, they produce more offspring than the environment is able to support
● This leads to competition for food and other resources which results in a ‘struggle for survival’
● Individuals with characteristics most suited to the environment have a higher chance of survival and

more chances to reproduce
● Therefore the alleles resulting in these characteristics are passed to their offspring at a higher rate

than those with characteristics less suited to survival
● This means that in the next generation, there will be a greater number of individuals with the better

adapted variations in characteristics
● This theory of natural selection was put forward by Charles Darwin and became known as ‘survival

of the fittest’

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Video #2- Charles Darwin and Natural Selection
Scan the code or type in the link https://tinyurl.com/y4yaddcj
Hover over the picture below and click on the link.
https://edpuzzle.com/media/5f934463f75b444096d8c6b0

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Design Your Own Beak activity- on your own

Bird beaks are incredibly diverse. Beaks can be thick and strong to crush nuts, curved like a

corkscrew to open snail shells, or even full of combs to make it possible to filter food out of water.
These differences arise from the adaptation of animals to their environments.

Beak Making Materials: Bring some materials from home

● Tape (masking, clear, duct, or whatever you have at home)

● Scissors

● Glue

● Card stock Examples of beaks made by students
● Cardboard

● Popsicle sticks

● Rubber bands

● Paper clips

● Plastic forks

● Plastic spoons

● Tweezers

● Bull dog clips

● Paper clips

● Clothes Pegs

● Any other suitable material of your choice

Make a simple outline of the design of your bird beak here- Planning and design

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Lesson Topic : Natural Selection and
Evolution - Examples of Natural Selection

Natural selection illustrated by snail shell colour
● Within the population of snails there is variation in shell colour
● Normal varieties of shell colours in this snail species is black or grey (as evidenced by the first
picture)
● Chance mutations lead to a small number of snails / one snail having a white shell
● This ‘small number’ is shown in the second diagram where there are less white shelled snails
than black or grey shelled snails
● The white shelled snail(s) survive longer
● This is the ‘survival of the fittest’, a term used to explain why some organisms succeed in the
competitive struggle for survival against other members of their population
● The reason the white shelled snail(s) survive longer is because they are better camouflaged
● This means that they are less likely to be seen by predators and eaten
● As they survive longer they get more opportunities to reproduce
● And so the allele for white shells is passed onto offspring more frequently than the alleles for
black or grey shells
● Over generations, this is repeated until the majority of snails in the population have white
shells
● The Peppered moth is another example of natural selection

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Bird Beak Student lab Sheet

Use a ruler to draw up your data table and record how many items
your beak was able to collect . Then compare with your classmates

Draw Table #1 here

Draw table #2 here

Discuss the survival rate of your Bird’s beak
__________________________________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________

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Weird Science - Reading Time - Read and answer the questions below

In some isolated locations, a single species will radiate into many species to fill different ecological roles
in the area. These species flocks are all very closely related, and they may evolve in a relatively short
amount of time. A famous example of a species flock is the cichlid fishes living in the lakes in east
Africa’s Rift Valley (SF Fig. 1.2 A).

The lakes are located on a divergent tectonic plate boundary and have changed quickly over time,
enabling the fairly rapid evolution of closely related species that are native to relatively small habitats.
Some cichlid fish species are found in only one small lake island

Species flocks are important in the study of evolutionary biology. In fact, the first identified species flock
was the finches studied by Charles Darwin in the Galapagos Islands. These finches factored heavily in
Darwin’s work on the theory of natural selection. T

he finches descended from a single ancestor who had arrived on the isolated islands, and over time,
diversified to take advantage of the wide variety of ecological roles available. Some finches developed
heavy seed-cracking bills, whereas others developed long, narrow bills for grabbing insects (SF Fig. 1.2
B). However, the finches kept many features in common, providing a clue to their close relationship to
one another and to their common ancestor..

Answer the following Questions below :

1. What does the term radiate means__________________________________________________
2. Identify one thing that must be common amongst a species flock

_____________________________________________________________________________
3. Who was the Scientist that studied the first identified species flock _______________________
4. What is the name of the isolated island ? ____________________________________________
5. Which species did he study ______________________________________________________-
6. List 2 ways cited in the passage how the species flock evolved

_____________________________________________________________________________

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Selective Breeding- Cornell notes

Topic: Selective Breeding
Essential Question : Why do Humans practice selective breeding
Question 1- What is Natural Selection ?
Question 2- Describe what causes competition
Question 3- Who is the scientist responsible for the theory of natural selection?

Selectively Breeding Animals

● Selective breeding of animals has been carried out by humans for thousands of years
● It takes place in the same way as selective breeding of plants
● Individuals with the characteristics you want are bred together (often several different parents all

with the desired characteristics are chosen so siblings do not have to be bred together in the next
generation)
● Offspring that show the desired characteristics are selected and bred together
● This process is repeated for many successive generations before you can definitely say you have a
‘new breed’ which will reliably show those selected characteristics in all offspring
● Animals are commonly selectively bred for various characteristics, including:

○ cows, goats and sheep that produce lots of milk or meat
○ chickens that lay large eggs
○ domestic dogs that have a gentle nature
○ sheep with good quality wool
○ horses with fine features and a very fast pace
● An example of an animal that has been selectively bred by humans in many ways to produce breeds
with many different characteristics is the domestic dog, all breeds of which are descended from
wolves

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Selective Breeding in Plants

● Plants are selectively bred by humans for development of many characteristics,
including:
○ disease resistance in food crops
○ increased crop yield
○ hardiness to weather conditions (e.g. drought tolerance)
○ better tasting fruits
○ large or unusual flowers

● An example of a plant that has been selectively bred in multiple ways is wild brassica,
which has given rise to cauliflower, cabbage, broccoli, brussel sprouts, kale and
kohlrabi:

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Artificial Selection- Annotate in your notebooks

Artificial Selection:

● Selective breeding means to select individuals with desirable characteristics and breed
them together

● The process doesn’t stop there though because it’s likely that not all of the offspring
will show the characteristics you want so offspring that do show the desired
characteristics are selected and bred together

● This process has to be repeated for many successive generations before you can
definitely say you have a ‘new breed’ which will reliably show those selected
characteristics in all offspring

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