Biology - Cells

Question 1

How many chromosomes does a human have?

Answer 1

23 pairs - 46

Question 2

How many pairs pf chromosomes to gamates have?

Answer 2

22

Question 3

What is a gene?

Answer 3

A section of DNA which control characteristics and contain dominant and recessive characteristics.

Question 4

What is cell mitosis

Answer 4

In cell biology, mitosis is a part of the cell cycle when replicated chromosomes are separated into two new nuclei. Cell division giving rise to genetically identical cells in which the chromosomes number is maintained.

Question 5

What happens in the 1st stage of the cell cycle?

Answer 5

Longest stage where cells grow bigger and increase mass carrying out their regular activities. They replicate DNA to for, copies to prepare for cell divsion. A lot of sub cellular structures also increase.

Question 6

What happens in the 2nd stage of the cycle?

Answer 6

Where cell division actually occurs when the cell divides the cytoplasm into two. It occurs concurrently in nuclear division - known as mitosis and miosis.

Question 7

What happens in stage 3 of the cell cycle?

Answer 7

Mitosis produces two new cells identical to each other and to the parent cell. Different parts of the cell (number of organelles) increases to ensure that two new cells receive copies of the original organelles

Question 8

Where is the original chromosome and its copy join at?

Answer 8

Chromatids

Question 9

What is the step by step process in which the chromatids effect cell division?

Answer 9

1) the chromatids line up along the centre of the cell membrane and the nucleus disappears
2) The chromatids start to separate going to different halves of the cell

Question 10

What does the membrane of the nucleus do?

Answer 10

Reforms around each set of chromosomes and the cell divides

Question 11

What is each new cell a copy of?

Answer 11

The original parent cell

Question 12

What is it called when a sperm and egg cell fuse?

Answer 12

A zygote (creating a single new cell)

Question 13

What do embryonic stem cells do?

Answer 13

Differentiate to form all specialised cells in a persons body

Question 14

What is another major cell that can also arise from stem cell differentiaton

Answer 14

Bone marrow

Question 15

What is an issue of using stem cells?

Answer 15

Many embryonic cells come from aborted embryos which is ethical reason (to be against it)

Question 16

Are all cells in a plant the same?

Answer 16

Yes

Question 17

What what happen if you moved the cells in a plant around?

Answer 17

They would just redifferentiate

Question 18

Are plants easily cloned?

Answer 18

Yes plants are easily cloned because they are the same and wouldn’t have any individual cells that would give them deformities and are easily copied (through the process of cell cloning via stem cells)

Question 19

What happens at undifferentiated cells (in plants) ?

Answer 19

Undifferentiated cells are formed at active regions of stems and roots known as meristems. The cells will elongate and grow before differentiating. Plants will keep producing plant cells which don’t differentiate until they are in their final positions as plants.

Question 20

What happens in the process of cell cloning (in plants) ?

Answer 20

Identical offspring is produced. Then huge numbers of cells can be produced from just a single leaf tissue. In differentiates in different conditions to form the different components of a plant (that is cloned)

Question 21

What are stem cells (in plants)?

Answer 21

Come from plant meristems to make clones of a plant at a rapid pace and allows us to produce a lot of plants very quickly. It also gives scientists a way of creating large populations of plant for research.