All Cells Arise From Other Cells

Question 1

Within multicellular organisms do all cells retain the ability to divide

Answer 1

No

Question 2

How many pairs of chromosomes do humans have

Answer 2

23 

Question 3

At what stage of the cell cycle does DNA replication occur

Answer 3

Interphase 

Question 4

Mitosis is a part of the cell cycle in which a eukaryotic cell divides to produce… containing

Answer 4

Two daughter cells
Identical copies of DNA

Question 5

What is the point where the sister chromatids joined called

Answer 5

Centromere

Question 6

What are the two stages of the cell cycle

Answer 6

Interfase and mitosis

Question 7

What are the subcategories of interphase

Answer 7

G1. S. G2.

Question 8

What happens in G1

Answer 8

Cell grows a new organelles and proteins made

Question 9

What happens in S

Answer 9

Cell replicates its DNA, ready to divide by mitosis

Question 10

What happens in G2

Answer 10

Cell keeps growing and proteins needed for cell division are made

Question 11

Labelled chromrosome

Answer 11

Centromere (dot in the middle)
Chromatid ( 1 side)
Sister chromatids (the strands on either side)

Question 12

What happens in Prophase

Answer 12

The chromosomes condense and become visible
Nuclear envelope breaks down and the chromosomes are free

Question 13

What happens during metaphase

Answer 13

The chromosomes lineup along the equator
spindle fibres attach the centromere

Question 14

What happens during anaphase

Answer 14

The centromeres splits separating into A pair of sister chromatids
The spindle fibres contract pulling chromosomes to opposite poles ( chromosomes are in a v shape)

Question 15

What happens during telophase

Answer 15

Chromatids become chromosomes
Nuclear envelope forms around each group of chromosomes


Question 16

What is cytokinesis

Answer 16

The division of the cytoplasm at the end of telophase 

Question 17

What can happen during uncontrolled mitosis

Answer 17

Uncontrolled cell division can lead to a tumour and therefore cancer

Question 18

Where are most cancer treatments directed

Answer 18

Controlling the rate of cell division

Question 19

What is the proteome of a cell

Answer 19

The number of different proteins a cell is able to produce

Question 20

Describe binary fission of bacteria

Answer 20

Replication of DNA
Replication of plasmids
Division of cytoplasm to produce two daughter cells

Question 21

Why would the percentage of cell under going mitosis decrease as the organism gets older

Answer 21

Cells lose the ability to divide

Question 22

Picture of chromosomes that are still connected and visible
Give two pieces of evidence that this cell was undergoing mitosis

Answer 22

The chromosomes are visible because they have condensed ( this is only 1 point not two)
Each chromosomes is made up of two chromatids because DNA has replicated

Question 23

When preparing the cells for observation the scientist placed them in a solution that had a slightly higher (less negative) water potential than the cytoplasm. This did not cause the cells to burst but moved the chromosomes further apart in order to reduce the overlapping of the chromosomes when observed with an optical microscope.
Suggest how this procedure moved the chromosomes apart. X2

Answer 23

Water moves into the cells by osmosis
Cells get bigger

Question 24

Suggest a way that chromosomes differ along their length. That when dyed different areas are darker or lighter

Answer 24

Different genes
Different base sequence
Difference in histones

Question 25

What in picture shows that the cell was in anaphase

Answer 25

Chromatids are in two groups one each either polve
V-shaped SHOWED THAT THEY HAVE BEEN PULLED AT THEIR CENTROMERES

Question 26

When does non-disjunction occur

Answer 26

Meiosis