Chapter 4.2 Environmental Factors ✓

Question 1

What are some external factors that influence phenotype?

Answer 1

-Temperature
-pH
-Availability of food
-Light exposure
-Wind exposure

Question 2

Define genome

Answer 2

All of the genetic material contained in an organism or a cell

Question 3

What internal environmental factor influences phenotype and how does it influence it?

Answer 3

Hormones influence phenotype by interacting with genes. They affect how traits are expressed, influencing the phenotype and behaviour
For example, Growth Hormone affects height and bone development, whole thyroid hormones regulate metabolism and energy levels

Question 4

Define epigenetics

Answer 4

The study of inheritable, but reversible, changes caused by chemicals that control the activity of DNA.

Question 5

How does epigenetics influence phenotype?

Answer 5

It influences phenotype by controlling gene expression which can influence the growth and development of organisms. Changes to the epigenome can impact traits without altering the DNA sequence, thus influencing the phenotype

Question 6

How does the addition of an acetyl group influence gene expression/

Answer 6

The addition of an acetyl group to chromatin structure promotes transcription and turns a gene on

Question 7

How does the addition of a methyl group influence gene expression?

Answer 7

The addition of a methyl group to a histone reduced transcription and turns a gene off. Removal of some methyl groups can also turn genes on

Question 8

Can epigenetic changes be inherited?

Answer 8

yes