1.3 Cell Differentiation

Question 1

What is the Hierarchy of Life?

Answer 1

Cell - Tissue - Organ - Organ system - Organism

Question 2

What is Cell differentiation?

Answer 2

The process where a cell takes on a specific form and function to become specialised is called differentiation.

Question 3

What is a gamete?

Answer 3

When most organisms reproduce, sex cells containing the normal number of chromosomes are produced.

Question 4

What is a zygote

Answer 4

A single egg cell, a fertilized female gamete by a male gamete, forms a zygote.

Question 5

What is an embryo

Answer 5

An embryo is a zygote that undergoes a series of mitotic divisions, rapidly increasing in cell number forming an embryo. (CELLS IN THE EMBRYO ARE NOT SPECIALISED YET)

Question 6

What is gene expression

Answer 6

Genes that are ‘expressed’ means that the genetic information it carries is being used to produce a protein
These genes are said to be switched ON

Genes that are ‘not expressed’ means that the genetic information is not being used to produce a protein
These genes are said to be switched OFF

Question 7

What is an activator

Answer 7

They are proteins that bind to a gene’s promoter, which causes the DNA to change shape and slightly open up for transcription to occur.

Question 8

What are repressors

Answer 8

These are proteins that bind to a gene’s promoter.
They cause the DNA to coil up tightly and the gene becomes less accessible.

Question 9

What can environmental factors do?

Answer 9

They can alter gene expression, and therefore a multicellular organism’s phenotype (physics features)