Unit 8 Lesson 10: Analyzing Data About Traits

Question 1

The environment can play an important role in the

Answer 1

characteristics of organisms.

Question 2

The environment can play an important role in the characteristics of organisms. Elaborate

Answer 2

For example, a dry season can ruin crop yields for plants that are not drought tolerant.

Question 3

distribution

Answer 3

distribution – how the variation in traits is spread across a population

Question 4

variation

Answer 4

variation – the different traits that are found in a population

Question 5

he variation and distribution of traits in a population is due to

Answer 5

The variation and distribution of traits in a population is due to genetic and environmental factors.

Question 6

Scientists can compare a species with two genetically similar populations that express different phenotypes under different environmental conditions. What impact do these studies have

Answer 6

These studies can help determine if certain traits are influenced by environmental factors. Examples of traits that can be influenced by environmental factors include gender and skin (or fur) color.

Question 7

Determining the average temperature of the beach where turtles lay their eggs is one way that scientists discovered how temperature affected the gender of sea turtles. Elaborate

Answer 7

The temperature of the sand surrounding the developing eggs of sea turtles determines if the hatchlings will be male or female. When the sand is warmer, there are more female turtles hatched

Question 8

How is the gender of alligators and croocodiles determined

Answer 8

The gender of alligators and crocodiles is also dependent on temperature.

Question 9

Mendelian Traits

Answer 9

Mendelian Traits – traits that are controlled by a single gene and have little variation

Question 10

Examples of a flower with mendelian traits

Answer 10

pea plant flower color

Question 11

Some traits are expressed through polygenic inheritance, whats that

Answer 11

polygenic inheritance – a trait is controlled by more than one gene

Question 12

Example of polygenic inheritance

Answer 12

An example is kernel color in wheat. The three different genes and their alleles allow for a range of variation in color.

Question 13

When analyzing polygenic inheritance traits, what will scientists

Answer 13

When analyzing polygenic inheritance traits, scientists will observe a wide variation of the trait.

Question 14

When analyzing polygenic inheritance traits, scientists will observe a wide variation of the trait. What kind of distrubiuion pattern will this result in

Answer 14

This will result in a bell-shaped distribution pattern, where there are not very many organisms at the extreme ends.

Question 15

On a bell-shaped distribution where are the most common triats

Answer 15

The more common traits are those that lie in the middle of the bell-shaped distribution.

Question 16

What kind of traits can a bell-shaped distubtion represent

Answer 16

his type of statistical analysis of expressed traits are only for traits that are given a quantitative or numerical value.

Question 17

Mendelian traits tend to fall into a few distinct classes such as

Answer 17

the color of pea pods, plant height, and flower color. These classes do not lend themselves to this type of analysis.

Question 18

Mendelian traits have limited variation in

Answer 18

phenotypes

Question 19

Traits such as crop yield, weight of animals, and disease resistance in plants can be easily

Answer 19

quantified and analyzed in a distribution graph.

Question 20

This bell-shaped curve is called

Answer 20

normal distribution

Question 21

normal distribution is found all over nature. What does it mean

Answer 21

normal distribution – a distribution that has a bell-shaped curve with more traits being expressed in the middle and the extreme variations at each end

Question 22

Most of traits in nature follow what kind of distribution

Answer 22

Most of traits in nature follow a normal distribution where most organisms display middle ranged traits with fewer at the extremes.

Question 23

A survey of 100 high school seniors in the United States showed the following results in IQ scores.

Test Score Range

Number of Students

0 - 60

0

61 - 75

10

76 - 100

27

101 - 110

50

111 - 150

12

151 - 180

1

Would this survey of 100 students result in a normal distribution?

Answer 23

Look at the number of students that tested in each of the ranges. Without having to graph, we can determine that this is a normal distribution because the number of students in the middle or average range is higher than those at both extremes.

Question 24

What are some examples of how the environment can influence the traits of an organism?

Answer 24

Dry conditions such as a drought or dry year can ruin crops that are not drought resistant. Temperature during egg development can affect the gender of some animals such as turtles and crocodiles.

Question 25

Populations can be genetically similar and express different phenotypes. Analyzing the environment can help determine if it is the cause of the differences.

Is the second statement true or false?

Answer 25

true; Environmental factors can influence the phenotypes of organisms.

Question 26

genotype vs phenotype

Answer 26

The genotype of an organism is the set of genes that can be found on the DNA, and the phenotype is the physical characteristics of an organism due to the genotype.

Question 27

What are examples of mendelian traits

Answer 27

reckles on the face or dimples in the cheeks. Other examples could include a hitchhiker’s thumb and widow’s peak.

Question 28

Mendelian traits are typical examples that are used to

Answer 28

teach genetics.

Question 29

What are examples Polygenic Inheritance

Answer 29

An example is height in humans. There is a wide variation in height in humans, unlike other species, such as pea plants, which can be classified as simply short or tall. Additional examples of polygenic inheritance include skin color, eye color, weight, and hair color.

Question 30

Where would a person who has all dominant alleles for tallness fall on the bell curve?

Answer 30

Since having both dominant alleles for tall would be an example of an extreme case, the person would be on the far right of the bell curve. The middle area would be for average height and the far left would be for the shortest of the population.

Question 31

Where would a person who has all dominant alleles for tallness fall on the bell curve?

Answer 31

Since having both dominant alleles for tall would be an example of an extreme case, the person would be on the far right of the bell curve. The middle area would be for average height and the far left would be for the shortest of the population.

Question 32

Think about the different variations of some traits for humans. Decide which of the following is not an example of a polygenic trait.
skin color
freckles
height
brown hair

Answer 32

freckles

Question 33

The condition phenylketonuria, or PKU, is caused by the toxic buildup of the amino acid phenylalanine, which is found in all proteins and even some artificial sweeteners. The buildup in the blood affects nerve and brain development. PKU is caused by a mutation in a gene that affects the breakdown of phenylalanine. When foods that contain phenylalanine were removed from the diet, the effects of PKU were reduced. How does this demonstrate the relationship between a trait’s occurrence and environmental factors? Should evidence of an environmental influence cause scientists to completely ignore genetic tendencies?

Answer 33

The effects of PKU are not seen as often when certain foods are removed from the diet, showing that the condition is also related to environmental factors. Scientists should not ignore genetic tendencies, since a person’s environment is subject to change throughout their lifetime. Traits that may be hidden or overshadowed by an environmental effect at this moment, may prove significant when the environment changes or later in life.