module 4 - producing new cells

Question 1

what is mitosis?

Answer 1

it is the process of a diploid cell dividing, and is controlled by the nucleus

Question 2

what is a chromatid?

Answer 2

one of the 2 complete copies of a chromosome attached to each other during mitosis

Question 3

what is a stem cell?

Answer 3

-unspecialised cells in animals which can divide in order to self-renew.
-they have the potential to become different types of cell.
-they are involved in growth and repair

Question 4

what is a system?

Answer 4

a group of organs which work together

Question 5

what does the specialisation of cells lead to?

Answer 5

it leads to the formation of a variety of cells, tissues, and organs

Question 6

what is a diploid?

Answer 6

it is two sets of matching chromosomes in one cell

Question 7

what is a heirarchy?

Answer 7

it is the order of the different levels of complexity from cells to systems

Question 8

what is a chromosome complement?

Answer 8

it is the number of chromosomes typical of a particular species

Question 9

how many chromosomes are there in the human body?

Answer 9

46 and these are arranged into 23 pairs

Question 10

what do all body cells contain?

Answer 10

they all contain 2 sets of matching chromosomes- one set from the mother and one set from the father.

Question 11

why are certain cells called diploids?

Answer 11

because they have 2 sets of matching chromosomes

Question 12

what is the number of chromosomes a diploid cell contains called?

Answer 12

its diploid chromosome complement, each species will have its own chromosome complement

Question 13

what is the chromosome complement of a human cell?

Answer 13

46

Question 14

what is a chromosome made of?

Answer 14

two chromatids joined at the centromere

Question 15

what does DNA replication make?

Answer 15

it makes a copy of each chromosome before mitosis and cell division

Question 16

what is it called when 2 chromatids join together?

Answer 16

A chromosome

Question 17

what is the combination of 2 joined chromatids called?

Answer 17

it is still called one chromosome

Question 18

why do cells need to divide?

Answer 18

-when unicellular organisms divide, they form a complete copy of themselves
-multicellular organisms divide to produce new cells for growth, and repair of damaged tissues and replacement of dead and damaged cells

Question 19

what happens during mitosis?

Answer 19

two identical daughter cells are produced which contain the same number of chromosomes as the parent cell

Question 20

why is what happens during mitosis important?

Answer 20

so that they maintain the diploid chromosome complement and so that the cell can carry out the same functions as the parent cell

Question 21

what is stage 2 of mitosis?

Answer 21

chromosomes make copies of themselves and become visible as pairs of identical chromatids

Question 22

what is stage 3 of mitosis?

Answer 22

chromosomes line up at the equator of the cell

Question 23

what is stage 4 of mitosis?

Answer 23

spindle fibres attach to chromosomes and chromatids are pulled apart

Question 24

what is stage 5 of mitosis?

Answer 24

chromatids move to opposite poles

Question 25

what is stage 6 of mitosis?

Answer 25

nuclear membrane forms and cytoplasm divides

Question 26

what does the nucleus contain during mitosis?

Answer 26

long uncoiled chromosomes which are difficult to see

Question 27

how do stem cells self renew?

Answer 27

by cell division

Question 28

what are the types of stem cells?

Answer 28

-embryonic stem cells -tissue stem cells

Question 29

what are embryonic stem cells derived from?

Answer 29

embryos that develop from eggs that have been fertilised in a laboratory

Question 30

what do stem cells reside among?

Answer 30

differentiated cells in a tissue or organ, they are found in many tissues such as bone marrow, brain, skeletal muscle, blood vessels, skin, liver, teeth, and the heart

Question 31

what do stem cells do?

Answer 31

regenerate surrounding cells damaged by disease, injury, and every day wear and tear

Question 32

what is a nerve cells structure and function?

Answer 32

long connection length for transmitting signals over long distances from sensors to the brain

Question 33

what is are red blood cells structure and function?

Answer 33

they have a biconcave shape and no nucleus giving them a large surface area so it can carry more oxygen

Question 34

what is a sperm cells structure and function?

Answer 34

has a tail to swim to the egg and fertilise it

Question 35

what is a root hair cells structure and function?

Answer 35

long and thin so it has a large surface area to absorb more water

Question 36

what is a leaf palisade cells structure and function?

Answer 36

has many chloroplasts to carry out photosynthesis

Question 37

what are tissues made up of?

Answer 37

many copies of a specialised cell type

Question 38

what combines to make an organ?

Answer 38

different tissue types

Question 39

what do organs work together to form?

Answer 39

a system

Question 40

What is stage 1 of mitosis?

Answer 40

Nucleus contains long uncoiled chromosomes which are difficult to see

Question 41

What are some substances that move by diffusion?

Answer 41

-oxygen -nutrients -waste products

Question 42

What are some substances that move by active transport?

Answer 42

-sugars -most amino acids