Cell Specialisation

Question 1

What is a gamete?

Answer 1

The male or female sex cell. It is haploid cell formed by meiosis. In humans they are the ovum and sperm cell?

Question 2

What is fertilisation?

Answer 2

Is the fusion of male and female gamete to form a diploid zygote.

Question 3

What is Zygote?

Answer 3

It is a diploid cell formed after the fusion of male and female gametes. It is the fertilised egg cell. It is a stem cell.

Question 4

What are stem cells?

Answer 4

Stem cells are specialised cells that can develope into many different types of cells.

Question 5

What are the two important characteristic of stem cells?

Answer 5

1. Retain their ability to divide
2. Differentiation

Question 6

What are the three kinds of stem cells?

Answer 6

1. Embryonic stem cells
2. Adult stem cells
3. Induced pluripotent stem cells

Question 7

What are stem cell niches?

Answer 7

Stem cell niches are located within the body where a pool of adult stem cells are maintained.

Question 8

What can stem cells do? (2)

Answer 8

1. Self renew - when they divide one will stay behind to maintain the stock of stem cells. The others can differentiate.
2. Create functional tissue - cells differentiate to grow, replace, or repair specialised tissues

Question 9

What is a totipotent stem cell?

Answer 9

“Whole” Can become any body cell (including placenta in placental / mammals (s)). It can form a whole organism. They exist in a zygote and early embryo developments.

Question 10

What is a pluripotent stem cell?

Answer 10

“many” Arise from totipotent stem cells, they can become a range of body cells, they cannot form a complete organism. The inner cell mass of a blastocyst is pluripotent.

Question 11

What is a multipotent stem cell?

Answer 11

“several” Can only form a limited number of closely related cell types. Present in later in embryo development and often in adults.

Question 12

What is a unipotent stem cell?

Answer 12

They can only divide into their associated cell types.

Question 13

What is differentiation?

Answer 13

It is the process during development whereby newly formed cells become more specialised distinct from one another as they mature.

Question 14

What adaptions can be made to increase surface area to volume ratio? (3)

Answer 14

Microvilli
Flattening
Invagination

Question 15

What is flattening?

Answer 15

Some cells have evolved a thin flattened shape to increase the SA:Vol ratio.

Question 16

What is microvilli?

Answer 16

Some cells have evolved long bristle like extensions called microvilli.

Question 17

What is invagination?

Answer 17

Cell invaginations are the folding or inward projection of the cell membrane, creating various internal structures with increased surface area.