Cells And Control

Question 1

What is mitosis ? What is it used for

Answer 1

The stage of the cell cycle when the cell divides. Organisms use mitosis to grow or replace cells that have been damaged. Some organisms use mitosis to reproduce (asexual reproduction)

Question 2

What are the stages of mitosis

Answer 2

Prophase, metaphase, anaphase and telophase

Question 3

What happens during cytokinesis

Answer 3

Cytoplasm and cell membrane divide to form two separate cells

Question 4

A normals human body contains 23 pairs of chromosomes. How many chromosomes would be in each new human cell formed by mitosis

Answer 4

Each cell has 46 chromosomes (23 pairs)

Question 5

Name 2 methods plants use to grow

Answer 5

Cell division
Cell elongation

Question 6

What does is mean if a baby measures at the 50th percentile for weight

Answer 6

The baby is an average weight for its age, roughly around 50% of babies it’s age are heavier and 50% of babies it’s age are lighter

Question 7

Why is cell differentiation important

Answer 7

It allows cells to become specialized for a specific job. Having specialized cells allows multicellular organisms to work more efficiently

Question 8

How does the ability to differentiate differ between plant cells and animals cells?

Answer 8

The ability to differentiate is lost at an early stage in most animal cells (after they have become specialized), but lots of plant cells don’t ever lose this ability

Question 9

What are growth charts used for

Answer 9

To assess a child’s growth over time, so any problems can be highlighted

Question 10

Describe how cancer can develop from changed in a cell

Answer 10

If there is a change in one of the genes that control cell division, the cell may start dividing uncontrollably. This can result in a mass of abnormal cells called a tumor. If the tumor invades and destroys surrounding tissue it is called cancer.

Question 11

True or false? muscles and glands are examples of receptors

Answer 11

False. They are effectors

Question 12

In humans what does the central nervous system consist of?

Answer 12

The brain and spinal cord

Question 13

Which type of neuron carries impulses from the central nervous system to effectors?

Answer 13

Motor neuron

Question 14

What is the benefit of an axon having a myelin sheath?

Answer 14

A myelin sheath acts as an electrical insulator, which speeds up the movement of electrical impulses along the axon

Question 15

Describe the difference in function between dendrons and axons

Answer 15

Dendrons carry nerve impulses towards the cell body, whereas axons carry nerve impulses away from The cell body

Question 16

Compare the difference in structure of a sensory and motor neuron

Answer 16

Sensory neurons have one long dendron and one short axon, whereas motor neurons have many short dendrites, and one long axon

Question 17

Describe the structure and function of a relay neuron

Answer 17

A Relay neuron has many short dendrites that carry nerve impulses from sensory neurons to the cell body. It has an axon that carries nerve impulses from the cell body to motor neurons.

Question 18

What is an embryonic stem cell?

Answer 18

An undifferentiated cell found in early human embryos, which has the potential to divide and produce any kind of cell at all

Question 19

Where can stem cells be found in an adult human? What do they do?

Answer 19

E.G bone marrow. they are used to replace damaged cells such as blood or skin cells

Question 20

What type of plant tissue contains stem cells?

Answer 20

Meristem tissue (this is where growth occurs)

Question 21

Describe two potential risks of using stem cells in medicine

Answer 21

If donor stem cells are contaminated with a virus, the virus could be passed on to the recipient.
If the cells divide to quickly inside a patient, a tumor may develop.
if the transplanted cells aren’t grown using the patients own stem cells, their body might reject them.