​What role does chance play in inheritance?

​1. Obtain two dice of different colors. With a partner, roll the dice 10 times. Make a data table to record the number of dots for each roll.

​2. Discuss with your partner how this activity might model reproduction. What do the colors represent? What do the dots represent?

​Inheritance and Traits

​Lesson 1

​Vocabulary

• ​trait

• ​inheritance

• ​gene

• ​genotype

• ​phenotype

• ​mutation

​What is inheretance

​1. a distinguishing characteristic of an organism is a trait

​2. traits are passed down from one generation to the next.

​3. the passing of traits from generation to generation is inheritance

​4. not all traits are inherited, if a parrot loses a claw, the offspring will not inherit that physical change

​Inheritance and DNA

​1. organisms can reproduce through asexual reproduction through cell division - the offspring are identical to the parent

​2. organisms can also reproduce through sexual reproduction, requiring two individual organisms - offspring are a mixture of traits from both parents

​3. sexual reproduction requires DNA from a sperm and egg cell

​

​DNA and Genes

​1. a gene is a section of DNA that has genetic information for one trait.

​2. Genes carry this information in a unique sequence within DNA.

​3. DNA strands can be 2m long, but are tightly coiled with proteins to form chromosomes.

​4. The number of chromosomes in cells differs depending on the species - humans have 23 pairs in each cell.

​5. One chromosome of the pair from the father, one from the mother.

​6. Reproductive cells have 23 single chromosomes.

​Combining Genes

• ​in sexual reproduction an egg and a sperm contribute a gene for a trait.

• ​each gene is called an allele

• ​meiosis is the process during which sperm and egg cells are formed.

• ​chromosome pairs are split into four genetically different cells

​Fertilization

• ​fertilization is the process of a sperm and egg uniting

• ​The egg and sperm chromosomes combine to form offspring with a full set of paired chromosomes

• ​billions of potential gene arrangements are possible between two parents.

​Influencing traits

1. an organisms complete set of genes is its genotype

​2. once inherited it remains unchanged.

​3. an organisms environment can influence how the traits are expressed.

​4. How the trait appears or expressed is the phenotype.

​cont.

​5. plants traits can be affected by the amount of light it receives since light is critical to the plant.

​6. plants receiving less sunlight might not grow as tall as those in full light.

​7. other factors such as nutrients in the soil can affect plants, similar to nutrition in animals.

​8. flamingoes for example are born white, but turn pink due to their diet high in red pigment.

​cont.

​9. social factors can also affect behavioral traits

​10. ex. flamingos will not mate in captivity unless they are in a flock of at least 20.

​11. locusts are typically solitary animals, but can form swarms when in large groups.

​Phenotype and Mutations

• ​a mutation is the only way that a change in a trait can be passed on to the next generation

• ​a mutation is a permanent change in the sequence of DNA in a gene

• ​can be caused by chemicals or radiation, but mostly at random

Effects of Mutations

​1. mutations are similar to misspelling a word, if you use the wrong letter in place of another, you could end up with a different meaning.

​2. mutations work in the same way, as they can cause the organisms to produce a different trait.

​3. some mutations are harmful, such as cancer or heart defects, but some can help an organism survive its environment.

​Adaptations in Species

​Lesson 2

​Vocab

​Variation

​Adaptation

​Natural Selection

​Selective Breeding

​Camouflage

​mimicry

​How alike are members of a population?

​1. It is easy to see the differences among people, but what about plants or animals? Are all robins alike? What about sunflower seeds?

​2. Place 10 sunflower seeds on a paper towel. Number the seeds 1-10 by writing on the paper towel below each seed.

​3. Use a magnifying lens to examine the seeds, focusing on how their coloration is alike or different, record your results.

​4. Use a metric ruler to measure the length of each seed. Measure the thickness of each seed at its thickest point.

​

​What is adaptation?

• ​members of species that reproduce sexually are all slightly different

• ​slight differences in inherited traits among individual members of a species is called variations

​cont.

​ - variations occur through mutations

​ - mutations can harm an individual, or be beneficial to their survival.

​ - an adaptation is an inherited trait that helps a species survive in its environment

​ - ex. a giraffe's spots - giraffe's have different spot patterns that help them blend into the environment, protecting them from predators

​How Adaptations Occur

• ​Giraffes spots could be the result of a mutation that occurred in an individual

• ​this trait was passed on through reproduction

• ​If the trait helps those individuals survive, they may be more likely to pass those traits on than others through survival

​Natural Selection

​1. Natural Selection is the process by which organisms with variations that help them survive in their environment live longer, compete better, and reproduce more than those that do not have the variation.

​2. If a variation helps an organism survive and out compete others, it may be more likely to produce more offspring, making that variation more common.

​3. Eventually, most of the population might have this variation.

​cont.

​4. adaptations that become common are typically dependent upon the environment

​5. The environment changes over time, sometimes fast due to things like volcanic eruptions, sometimes slow due to continents moving.

​6. When the environment changes, either a population adapts through natural selection or it dies off, possibly leading to extinction of a species

​The case of the peppered moth

• ​In early 1800s white only seen

• ​mid 1800s black spotted, eventually more and more frequently

• ​1900, black variation most common.

• ​due to darkening of surfaces from burning coal and industrial revolution

​Selective Breeding

• ​when humans breed organisms for food or for pets, they select variations that occur naturally

• ​selective breeding is the selection and breeding of organisms with desired traits

• ​by doing this, humans change traits just as natural selection does

Structural adaptations

• ​structural adaptations are a physical trait, such as shape, color or internal structure that increases survival

• ​ex. the color and shape of this insect's eyes are structural adaptations

​Behavioral Adaptation

• ​a behavior or action such as migration, hibernation, hunting at night, or playing dead, that increases survival

• ​ex, the snake playing dead, a behavioral adaptations to fool predators

​Functional adaptataion

• a biochemical change, such as hibernating, shedding or spitting, that enables a species to increase survival or maintain homeostasis

• ​ex. spraying venom as this cobra is doing

​Maintaining homeostasis

​ - the ability of an organism to keep its internal conditions within certain limits is homeostasis

​ - ex. maintaining your body temperature when it is cold outside, or when you are exercising.

​ - all species have adaptations that help them survive changes in the environment.

​ - ex. plants in deserts store water, fish have gills for taking oxygen from the water.

protection from predators

• species have adaptations to protect them from predators, ex. porcupines and quills

• ​some have camouflage, an adaptation that enables a species to bled in with their environment

• ​ex. stonefish -->

​mimicry

• ​mimicry is an adaptation in which one species looks like another

• ​this can mimic a poisonous animal, or something non desirable

• ​ex kingsnakes looking like coral snakes, viceroy butterfly mimicking a monarch

Food Gathering

​ - adaptation can also help a species find food

​ - camouflage not only hides from predators, but also prey

​ - anteaters have a long nose and tongue for gethering ants

​ - birds beaks are well adapted for their food, seeds, flesh scooping

​ - as a predator adapts to catch prey, so does the prey adapt to elude the predator

​movement

​ - cheetahs and gazelles have long, powerful legs, adapted to run fast

​ - legs, wings, flippers, fins and tails are all adaptations

​