2.6.4- Diversity In Animal Cells

Question 1

What are epithelial cells?

Answer 1

Cells that constitute lining tissue.

Question 2

What is an erythrocyte?

Answer 2

A red blood cell.

Question 3

What is a neutrophil?

Answer 3

A type of red blood cell that is phagocytic- can invest microbes and small particles.

Question 4

Explain what a stem cell is.

Answer 4

An unspecialised cell able to express all of its genes and divide by mitosis.

Question 5

Single called organisms are small and therefore have a large what?

Answer 5

Surface area to volume ratio.

Question 6

Give two reasons for the need of a large SA:V ratio.

Answer 6

It means lots of oxygen can quickly and efficiently diffuse into the cell and waste products can diffuse out of the membrane efficiently.

Question 7

Why do larger organisms need specialised cells?

Answer 7

Most of their cells aren’t in contact directly with the exterior environment, therefore they need specialised cells to carry out a particular function.

Question 8

How does a multicellular embryonic organism start life?

Answer 8

As a single undifferentiated cell called a zygote.

Question 9

Explain how a zygote forms.

Answer 9

The suite is made when an ovum is fertilised by a sperm and the two haploid nucleus’ fuse (= diploid nucleus). The zygote is unspecialised and all of the genes in its genome an be expressed and t an divide by mitosis.

Question 10

What is a genome?

Answer 10

The genetic material within an individual.

Question 11

What can happen to genes during differentiation?

Answer 11

Some can be swifter off and some expressed more.

Question 12

List three reasons as to why certain genes may be switched off or expressed more during differentiation.

Answer 12

The proportions of the different organelles differs from those of other cells, the shape of the cell changes and some of the contents of the cell changes.

Question 13

From where do erythrocytes and neutrophils derive?

Answer 13

The stem cells within bone marrow.

Question 14

List the five types of specialised animal cells.

Answer 14

Neutrophil
Erythrocyte 
Spermatozoa 
Ciliated epithelia
Squamous epithelia

Question 15

What is the function of erythrocytes?

Answer 15

They carry oxygen from the lungs to respiring cells.

Question 16

List all of the adaptations of erythrocytes to make them more efficient for their function of carrying oxygen from lungs to respiring cells.

Answer 16

They are small (7.5 micrometers) and biconcave shape= large SA:V= quicker O2 did fiction into cell/ well developed cytoskeleton- v flexible- can change shape and twist and turn to fit through narrow capillaries/ in differentiation, the ER, mitochondria and nucleus are lost to make more space for more haemoglobin.

Question 17

What is the function of neutrophils?

Answer 17

To ingest invading pathogens by phagocytosis.

Question 18

Explain the adaptations of neutrophils for its function.

Answer 18

x2 size of erythrocytes, have receptors on the plasma membrane to let opsonin bind, lobed nucleus- lets cell squeeze through narrow gaps, many lysosomes with lysin, lots of ribosomes to synthesise the enzymes needed, well developed cytoskeleton- flexible- phagocytosis.

Question 19

What is a spermatozoa?

Answer 19

The make sex cells.

Question 20

What are the three adaptations of the spermatozoa for its function?

Answer 20

small long+ thin- easily move// mitochondria provide ATP so tail moves// enzymes in its head that digest the outer layer of the ovum so the sperm can enter its nucleus.

Question 21

Explain the function of squamous epithelial cells.

Answer 21

It is lining tissue that is a mediator for the filtration and diffusion of a cell

Question 22

Explain the function of the ciliated epithelial cells.

Answer 22

To move particles or fluid over the epithelial surface, in structures like the trachea or nasal system.

Question 23

Explain some adaptations of squamous epithelial cells for its function.

Answer 23

Small, thin and flattened cells that allow small molecules to diffuse quickly and easily across the surface. They have transmembrane protein channels that allow ions to diffuse through the membrane.

Question 24

Explain some adaptations of ciliated epithelia cells for their function.

Answer 24

That have a large SA:V ratio and a thin membrane to allow short diffusion path if it’s needed (eg in the small intestine) and the long protrusions move things (eg. The mucus bang in the trachea).

Question 25

What is differentiation?

Answer 25

The process by which stem cells become specialised into different types of cell.