B3d-cell Division Flashcards Preview

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Flashcards in B3d-cell Division Deck (14)
1

Why does multicellular require the development of specialised organ systems?

Communication between cells
Supplying the cells with nutrients
Controlling exchanges with the environment

2

What are the advantages of being multicellular?

Allows organism to be larger
Allows for cell differentiation
Allows organism to be more complex

3

Why do multicellular organisms require specialised organ systems?

Communication between cells
Supplying the cells with nutrients
Controlling exchanges with the environment

4

What is mitosis?

Process that produces new cells for growth and repair

5

What is mitosis needed for?

Replacement of worn out cells
Repair to damaged tissue
Asexual reproduction

6

What happens before mitosis?

Dna replicates

7

What happens to chromosomes jn mitosis?

-Chromosomes line up along centre of cell
-divide as cell fibres pull them apart
-two arms of each chromosome go to opposite poles of one cell
-cytoplasm divides and you get two new cells

8

Why are sperm cells produced in large numbers?

To increase the chance of fertilisation

9

What is meiosis?

Type of cell division that creates gametes

10

What is a diploid?

Two copies of each chromosome
Eg
Body cells

11

What is a haploid?

Contain one chromosome from each pair
Eg
Gametes

12

Why does fertilisation result in genetic variation?

Gametes combine to form a diploid zygote
Genes on the chromosome combine to control the characteristics of the zygote

13

How is the structure of a sperm cell adapted to its function?

Many mitochondria to provide energy
And acrosome that releases enzymes to digest the egg membrane

14

Why is the chromosome number halved and each cell genetically different in meiosis?

One chromosome from each pair separate to opposite poles of the cell in the first division
Chromosome divide and the copies move to opposite poles of the cell in the second division