Unit 8 Lesson 4: Environmental Genetic Variation

Question 1

Any errors that occur during replication or meiosis can result in inheritable genetic variations. What’s that

Answer 1

Inheritable genetic variations are changes in genetic material that can be passed to offspring

Question 2

What are other factors that can influence variations in genes

Answer 2

Other factors that can influence variations in genes include environmental factors.

Question 3

environmental factors

Answer 3

environmental factors – factors outside the body or from an organism’s habitat that react with DNA to affect genes.

Question 4

Examples of enviromental factors under an organims control

Answer 4

Some environmental factors are under an organism’s control, such as personal choices related to food, lifestyle, and exercise.

Question 5

Examples of factors not under an organims contrl

Answer 5

Other factors are not under an organism’s control, such as exposure to pollution, chemicals, extreme heat, or radiation.

Question 6

Effects of enviroment on E. Coil

Answer 6

For example, the bacteria E. coli is easily damaged or killed by extreme heat that the bacteria has no control over.

Question 7

What impact can enviormental factors have on DNA

Answer 7

Environmental factors can react with DNA, changing the way molecules bond with one another and increasing the likelihood that a mistake, or mutation, will be made in the nucleotide sequence during replication.

Question 8

mutation

Answer 8

a change in a DNA sequence

Question 9

What impact does radiation have on DNA

Answer 9

Radiation, for example, breaks apart the bonds that hold molecules together.

Question 10

What happens to DNA as radiation breaks the DNA bonds aprt

Answer 10

When radiation breaks these bonds apart in a DNA molecule, the DNA can split into pieces.

Question 11

When radiation breaks these bonds apart in a DNA molecule, the DNA can split into pieces. How can this cause mutations

Answer 11

The cell will try to put the pieces back together, but mistakes causing mutations can be made.

Question 12

When does DNA replication occur

Answer 12

Remember that DNA replication occurs before the cell divides during both the processes of mitosis and meiosis.

Question 13

Why is any mutation in genetic information likely to be passed on to offspring

Answer 13

The process of meiosis results in gametes, or sperm cells and egg cells, thus any mutation in genetic information is likely to be passed to offspring.

Question 14

What happens during the process of replication

Answer 14

During replication, enzymes “unzip” the DNA molecule in order to produce two identical, homologous, DNA molecules.

Question 15

What are the base paris that make up DNA

Answer 15

Base pairs that make up DNA are adenine (A), thymine (T), cytosine (C), and guanine (G), with A pairing with T and C pairing with G.

Question 16

Complementay base pairs importance in order elaborate

Answer 16

Complementary base pairs bond together in patterns that must be replicated exactly in order to preserve the genetic information that will be passed to the offspring. Any changes to the base pairs due to environmental factors can result in an inheritable genetic variation.

Question 17

What does Epigenetics involve

Answer 17

Epigenetics involves genetic changes that are not encoded in DNA but can still be passed from parent to offspring in gene expression.

Question 18

What effect do the molecules that make up the structure of chromosomes and DNA have?

Answer 18

The molecules that make up the structure of chromosomes and DNA do affect gene expression and they can mutate or change through certain processes.

Question 19

One type of epigenetic change is caused by a process called DNA methylation. Whats that

Answer 19

DNA methylation – groups of organic material (one carbon atom and three hydrogen atoms) that bond to DNA to aid in expressing gene traits

Question 20

What are Methyl groups

Answer 20

Methyl groups are small, organic molecular fragments composed of carbon and hydrogen that can attach to the chromatin molecules.

Question 21

What impact does DNA methylation have

Answer 21

This modification does not change the DNA sequence, but instead affects gene activity

Question 22

What “causes” DNA methylation

Answer 22

Studies have linked DNA methylation with poor diet, smoking, and pollutants

Question 23

( DNA methylation) What kind of mutation has been shown to led to cancer

Answer 23

A mutation in the ability control gene expression has been shown to lead to cancer.

Question 24

A mutation in the ability control gene expression has been shown to lead to cancer. What happens if this occurs in a sex cell

Answer 24

If the mutation occurs in a sex cell, a predisposition to cancer could be inherited.

Question 25

Another epigenetic change happens during histone modification. Whats that

Answer 25

changes made to the expression of certain genes when the histone proteins coil with chromatin to form the chromosomes

Question 26

What are histones

Answer 26

Recall that histones are protein molecules that provide structure to chromosomes.

Question 27

How does histones effect genes

Answer 27

Depicted as small spheres or discs, histones are wrapped up in chromatin fibers and effect when genes are “turned on” or “turned off” during transcription and protein synthesis.

Question 28

epigenetic changes

Answer 28

changes in the way genes are expressed rather than the way the DNA is sequenced

Question 29

What does epidentic changes determine

Answer 29

Epigenetic changes determine if genes are turned on or off, how genes are read, and what proteins are transcribed.

Question 30

Where do Epigenetic changes show up

Answer 30

They ultimately show up in the expressed traits of organisms, such as if a person is predisposed to certain diseases.

Question 31

What can Epigenetics impact

Answer 31

Epigenetics can also impact the function of a gene or how cells are differentiated, such as specialized liver or skin cells.

Question 32

How can Epigenetic changes be passed downed

Answer 32

Epigenetic changes can be passed to offspring if these changes occur in sperm cells or egg cells and can contribute to variations in genetic material.

Question 33

Which of the following can create changes that influence inheritable genetic variation?

The food that a person eats.
The amount of stress that a person has.
The pollutants or chemicals that a person is exposed to.
All of the above.

Answer 33

d. All of the above.

Question 34

Radiation is an environmental factor that can influence genetic information. Describe how radiation can create mutations.

Answer 34

Radiation breaks the bonds that hold the DNA molecule together. For example, the base pairs can break apart, and when the cell tries to repair them, the base pairs may not be placed in the correct order, resulting in mutations, or changes in the genetic sequence.

Question 35

DNA must be replicated before cell division. Describe the process of replication and how a mutation can occur.

Answer 35

In replication, DNA is “unzipped,” and a copy is made of the nucleotide sequence. If any of the base pairs are not correctly replicated, then there can be mutations, or changes in the genetic sequence.

Question 36

Environmental factors can affect inheritable genetic variation. Explain how this can occur.

Answer 36

Environmental factors, such as chemical pollutants and UV energy, can cause changes in the genetic material of organisms. These changes can then be inherited by the organisms’ offspring.

Question 37

Changes to DNA contribute to inheritable genetic variation. When do these changes occur in the life of a cell?

Answer 37

Changes to DNA that contribute to inheritable genetic variation occur during replication, which happens before cell division.

Question 38

In order for a change in genes to be inherited, where must the change occur?

Answer 38

The change in genes must occur in the egg and sperm cells, in order for the change to be passed on to the next generation.

Question 39

When there are changes to the body cells, what are the effects?

Answer 39

Changes to the body cells may or may not cause problems for the individual, but they are not inheritable by their offspring, because the changes aren’t present in the egg or sperm cells.