1.3 Cell differentiation

Question 1

List the hierarchy to create a living organism

Answer 1

Cells massed together form tissues

Tissues → Organ

Organs → Organ system

Organ systems → Organism

Question 2

What is a zygote?

Answer 2

The initial cell formed when a male and female gamete fuse during fertilisation

Question 3

What type of cell division does the zygote undergo?

Answer 3

-It undergoes a series of rapid miotic division called cleavage

Question 4

What is an embryo?

Answer 4

An embryo consists of cells derived from the zygote.
All cells are genetically identical and unspecialised without a specific shape, structure and function.

Question 5

What are the identical, unspecialised cells in the zygote called?

Answer 5

Embryonic stem cells

Question 6

What are stem cells?

Answer 6

Stem cells have the ability to form different shapes, structures and functions.

Question 7

What is cell differentiation

Answer 7

The process by which unspecialised cells develop into specialised cell to carry out specific functions

Question 8

What is the process of cell differentiation?

Answer 8

1) The genetic expression of a cell is turned on and off
2) This affects their shape and function
3) Finally the cell is specialised with a specific structure and function

Question 9

What is differential gene expression?

Answer 9

A variation of genes being switched on and off by cells with identical genomes

Question 10

What transcription proteins are used to control gene expression? Describe their function.

Answer 10

Activators: Switch genes on by making a gene more accessible to the transcription machinery. They bind to a gene’s promoter.
Repressors: Switch genes off by coiling a gene tightly to make it less accessible to transcription machinery.