cell biology

Question 1

What is a eukaryotic cell?

Answer 1

Animal and plant cells. They have a cell membrane, cytoplasm and a nucleus.

Question 2

What is a prokaryotic cell?

Answer 2

Bacterial cells. They have a cell membrane, cell wall and a unenclosed genetic material. They may have smaller rings of DNA called plasmids, or tails called flagellum.

Question 3

True or false: Eukaryotic cells are smaller than prokaryotic cells.

Answer 3

False, vice versa. Eukaryotic are measured in micrometres, prokaryotic are measured in nanometres.

Question 4

What sub- cellular structures are found in animal cells?

Answer 4

Nucleus, mitochondria, ribosomes, cytoplasm and a cell membrane.

Question 5

What sub- cellular structures are found in plant cells?

Answer 5

Nucleus, mitochondria, ribosomes, cytoplasm, a cell membrane, cell wall, chloroplasts, and a permanent vacuole.

Question 6

What is the function of a nucleus?

Answer 6

Contains the genetic material.

Question 7

What is the function of mitochondria?

Answer 7

Provides energy by carrying out aerobic respiration .

Question 8

What is the function of ribosomes?

Answer 8

To carry out proteinsynthesis.

Question 9

What is the function of cytoplasm?

Answer 9

Where most of the chemical reactions happen.

Question 10

What is the function of a cell membrane?

Answer 10

Controls the movement of substances in and out of the cell.

Question 11

What is the function of chloroplast?

Answer 11

Absorbs light for photosynthesis.

Question 12

What is the function of a permanent vacuole?

Answer 12

Filled with cell sap to help keep the cell turgid.

Question 13

What is the function of a cellulose cell wall?

Answer 13

Gives strength to the cell and supports the plant.

Question 14

What is the function of plasmids?

Answer 14

Additional genetic materials.

Question 15

What is the function of a flagellum?

Answer 15

A tail that helps the cell to move around.

Question 16

How is a sperm cell specialised to carry out its function?

Answer 16

Has a tail for swimming to the ovum, packed full of mitochondria to provide energy, sperm head (acrosome) contains enzymes to help break into the ovum.

Question 17

How is a nerve cell specialised to carry out its function?

Answer 17

Long thin axon allows nerve impulses to travel along the cell as it makes its way to and from the brain. Has many dendrites to pass nerve impulses to nearby nerve cells.

Question 18

How is a muscle cell specialised to carry out its function?

Answer 18

Contract and relax as part of a muscle tissue, for movement. Packed full of mitochondria for energy.

Question 19

How is a ovum cell specialised to carry out its function?

Answer 19

The cytoplasm contains nutrients and many mitochondria to provide energy for mitosis and fertilisation. Has a special cell membrane which allows only one sperm cell to fertilise it.

Question 20

How is a root hair cell specialised to carry out its function?

Answer 20

Take up water and mineral ions for the plant. Long thin hair to increase the surface area over which water can be absorbed.

Question 21

How is a xylem cell specialised to carry out its function?

Answer 21

Transport water from the roots to the leaves, as a part of the tissue. Cells have no ends and are hollow to make a tube for water to move through. Lignin in the cell wall to waterproof the cell.

Question 22

How is a phloem cell specialised to carry out its function?

Answer 22

Transports sugars around the plant, as a tissue. Small holes in the end plates allow sugars to move through the cells.

Question 23

How is a ciliated epithelial cell specialised to carry out its function?

Answer 23

Found in lungs and oviducts. Has many cilia on the top surface of the cell- these help move mucus out of the lungs, or move an ovum toward the uterus.

Question 24

When can you find stem cells: a) embryo
b) mature animal c) mature plant ?

Answer 24

a) embryo.

Question 25

magnification= ?

Answer 25

size of image ÷ size of real object.

Question 26

What is the magnification of a light microscope?

Answer 26

X 1500.

Question 27

What is the resolution of a light microscope?

Answer 27

200nm.

Question 28

What is the magnification of an electron microscope?

Answer 28

X 500000

Question 29

What is the resolution of an electron microscope?

Answer 29

0.1nm

Question 30

Sub- cellular _(a)_ can be seen with a _(b)_ microscope.

Answer 30

(a) structures (b) electron

Question 31

Bacteria reproduce by a process called _(a)_. This is where the bacterium _(b)_ its size and then divides into 2 _(c)_.

Answer 31

(a) binary fission (b) doubles (c) daughter cells

Question 32

To prevent contamination, what aseptic techniques are used?

Answer 32

sterilising petri dishes/ culture media as an autoclave. sterilising inoculation loops by passing them through a flame/ dipping into alcohol. securing the lid of a petri dish with tape, not incubating bacterial cultures about 25 degrees celcius.

Question 33

What is mitosis?

Answer 33

A type of cell division.

Question 34

Changes such as _(a)_ in the cell can cause uncontrolled cell division. This could lead to _(b)_.

Answer 34

(a) mutations (b) cancer

Question 35

During mitosis the _(a)_ chromosomes line up in the centre of the _(b)_. One set of chromosomes is pulled to each end of the cell, and the _(c)_ to form 2 new _(d)_. The cytoplasm and _(e)_ then divide to form 2 identical daughter cells. This process is called _(f)_.

Answer 35

(a) doubled (b) cell (c) nucleus (d) nuclei (e) cell membranes (f) cytokinesis

Question 36

What is mitosis for?

Answer 36

Growth of multicellular organisms, repair or damaged tissues, replacement of cells, asexual reproduction.

Question 37

How are mammalian lungs specialised for diffusion?

Answer 37

Many small alveoli give the lungs a larger surface area. A good blood supply helps maintain a large concentration gradient.

Question 38

How are mammalian small intestines specialised for diffusion?

Answer 38

Villi and microvilli give a larger surface area. A good blood supply helps maintain a large concentration gradient.

Question 39

How are fish gills specialised for diffusion?

Answer 39

Have a large surface area.

Question 40

How are plant roots specialised for diffusion?

Answer 40

Root hair cells have long hairs that increase surface area.

Question 41

How are plant leaves specialised for diffusion?

Answer 41

Have large air spaces inside the leaf and many holes (stomata) on the underside of the leaf.

Question 42

If cells are in a _(a)_ solution, water moves into the cells. This causes plant cells to _(b)_ and become _(c)_, and animal cells will burst.

Answer 42

(a) dilute (b) swell (c) turgid

Question 43

If cells are in a concentrated solution, water moves _(a)_ of the cell. This causes plant cells to become _(b)_ and _(c)_, and animal cells to shrivel and _(d)_

Answer 43

(a) out (b) flaccid (c) plasmolysed (d) crenate

Question 44

What can the amount of water intake by osmosis be measured by?

Answer 44

A Visking osmometer, or measuring the mass of plants before and after placing them in solutions.

Question 45

What is active transport?

Answer 45

The movement of particles against the concentration gradient.

Question 46

What does the waxy cuticle do?

Answer 46

Allows light to enter the cell.

Question 47

What does the upper epidermis do?

Answer 47

helps protect the leaf by aiding in preventing water loss

Question 48

What does the palisade mesophyll do?

Answer 48

most of the photosynthesis in the cell.

Question 49

What does the spongy mesophyll do?

Answer 49

gas exchange, thin layer of water for gases to dissolve in.

Question 50

What do the guard cells do?

Answer 50

allow gas exchange and controls water loss.

Question 51

What are the similarities/ differences between xylem and phloem tissues

Answer 51

xylem is made of dead cells, phloem is made of living cells. phloem have pores in their end walls, xylem cells do not. xylem is hollow, phloem has cytoplasm. xylem has lignin, phloem does not. both are made of cells. xylem transports mineral ions/ water phloem transports sugars. both transport liquids/ substances though the plant.