6 Cell Division/ cellular organisation

Question 1

What is a gene

Answer 1

A gene is a section of DNA

Question 2

what are histone proteins

Answer 2

A histone is a protein that provides structural support for a chromosome. Each chromosome contains a long molecule of DNA, which must fit into the cell nucleus. To do that, the DNA wraps around complexes of histone proteins, giving the chromosome a more compact shape.

Question 3

what are chromosomes

Answer 3

a threadlike structure of nucleic acids and protein found in the nucleus , makes up genes

Question 4

what are chromatids

Answer 4

each of the two threadlike strands into which a chromosome divides longitudinally during cell division.

Question 5

what is a centromere

Answer 5

the region of a chromosome to which the microtubules of the spindle attach, that holds together the two chromatids

Question 6

what is a centriole

Answer 6

Centrioles are paired barrel-shaped organelles located in the cytoplasm of animal cells near the nuclear envelope. Centrioles play a role in organizing microtubules that serve as the cell’s skeletal system. They help determine the locations of the nucleus and other organelles within the cell.

Question 7

what’s the main difference between meiosis and mitosis

Answer 7

In mitosis there are 2 identical cells produced

In meiosis there are 4 semi identical cells produced

Question 8

how many daughter cells are produced in mitosis

Answer 8

2

Question 9

how many daughter cells are produced in meiosis

Answer 9

4

Question 10

how many cell divisions are their per cycle in meiosis

Answer 10

2

Question 11

how many cell divisions are their per cycle in mitosis

Answer 11

1

Question 12

is their variation in meiosis

Answer 12

yes

Question 13

is their variation in mitosis

Answer 13

no

Question 14

what’s the order of events in mitosis (egg telophase ect )

Answer 14

interphase
prophase
metaphase
anaphase
telophase.

Question 15

what happens in mitosis interphase

Answer 15

During interphase, the cell acquires nutrients, creates and uses proteins and other molecules, and starts the process of cell division by replicating the DNA.

Question 16

what happens in mitosis prophase

Answer 16

separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses.

Question 17

what happens in mitosis metaphase

Answer 17

individual chromosomes are spread out in the cell nucleus. During metaphase, the nucleus dissolves and the cell’s chromosomes condense and move together, aligning in the centre of the cell through the use of spindle fibres.

Question 18

what happens in mitosis anaphase

Answer 18

the sister chromatids separate from each other and are pulled towards opposite ends of the cell

Question 19

what happens in mitosis telophase

Answer 19

membranes form around the two groups of chromosomes, each at opposite ends of the cell, to produce the two nuclei of the daughter cells. The spindle disappears, and the cytoplasm usually divides

Question 20

at what stage to spindle fibres appear

Answer 20

prophase

Question 21

at what stage to spindle fibres disappear

Answer 21

telophase

Question 22

what’s a Red blood cell called

Answer 22

Erythrocyte

Question 23

What’s a white blood cell called

Answer 23

Neutrophil

Question 24

what is squamous epithelium (2)

Answer 24

-flattened epithelial cells
-used to line surfaces within the body, almost no friction

Question 25

What is ciliated epithelium (3)

Answer 25

• columnar epithelium
• More trapped dust out of trachea
• Extension from cytoplasm (cilia)

Question 26

what are the 3 types of cartilage + where they are located

Answer 26

Hyaline - nose, ends of long bones

Fibrous - vertebrae disks, in knee

Elastic - outer ear

Question 27

Palisade cells (4)

Answer 27

• in mesophyll
• contain chloroplasts
• thin cell walls
• large vacuole (maintains turgor pressure)

Question 28

Root hair cells (2)

Answer 28

-near the growing tips of roots
-extensions of root hairs (increase SA)

Question 29

how do Guard cells work (4)

Answer 29

When guard cells lose water and become less swollen as a result of osmatic forces, they change shape and the stoma closes to prevent further water loss.

the cell wall of a guard cell is thicker on one side so the cell doesn’t change shape symmetrically as its volume changes.

they contain more mitochondria to produce ATP in order to let movement against the concentration gradient

Vacuole to take up water and become turgid

Question 30

Why does overwatering kill plants (3)

Answer 30

-water floods soil, pushes oxygen out which is needed for respiration to produce ATP- minerals more scares

-ATP is needed to bring minerals in to attract water, as the water potential in the root hair cell is lowered, therefore no water brought in

• Plant collapsing (lack of water ), yellow leaves (lack of minerals)

Question 31

What are stem cells

Answer 31

undifferentiated cells (unspecialised)

Question 32

what is stem cell potancy

Answer 32

the higher the potency the more cells it can differentiate into

Question 33

what are totipotent cells

Answer 33

cells which can differentiate into any type of cell

Question 34

what are pluripotent cells

Answer 34

cells which can form all tissue types but not whole organisms

Question 35

what are multipotent cells

Answer 35

These stem cells can form a range of cells within a certain type of tissue

Question 36

What is the life span of a red blood cell

Answer 36

120 days

Question 37

what are uses of stem cells (10)

Answer 37

heart disease
type 1 diabetes
Parkinson’s disease
Alzheimer’s disease
macular degeneration
birth defects
spinal injury’s
burn treatment
drug trials
development biology