cell structure and organisation

Question 1

what are all organisms are made up of?

Answer 1

simple units called cells

Question 2

what is the protoplasm of a cell made up of?

Answer 2

cell surface membrane, cytoplasm, nucleus

Question 3

what is a cell surface membrane made up of?

Answer 3

lipids and proteins

Question 4

function of a cell surface membrane

Answer 4

controls substances entering or leaving the cell

Question 5

function of cytoplasm

Answer 5

where most cell activities occur

Question 6

what is the small round mass of denser protoplasm in the nucleus called?

Answer 6

nucleoplasm

Question 7

what is the membrane surrounding the nucleus called?

Answer 7

nuclear envelope

Question 8

functions of the nucleus

Answer 8

• controls cell activities such as cell growth and the repair of worn-out parts
• essential for cell division

Question 9

what is the cell wall made of?

Answer 9

cellulose

Question 10

is the cell wall partially or fully permeable?

Answer 10

fully permeable

Question 11

function of cell wall

Answer 11

protects the cell from injury and gives the plant cell a fixed shape

Question 12

what does the nuclear envelope do?

Answer 12

separates the contents of the nucleus from the rest of the cytoplasm

Question 13

function of nucleolus

Answer 13

plays a part in the making of proteins in the cell

Question 14

what is each chromatin thread made of?

Answer 14

proteins and deoxyribonucleic acid (DNA)

Question 15

the chromatin threads condense and become highly coiled structures called?

Answer 15

chromosomes

Question 16

function of ribosomes

Answer 16

synthesise proteins in the cell

Question 17

function of the smooth endoplasmic reticulum

Answer 17

• synthesises substances such as fats and steroids
• converts harmful substances into harmless materials (detoxification)

Question 18

function of the Golgi apparatus

Answer 18

• chemically modifies substances made by the ER
• stores and packages these substances in vesicles for secretion out of the cell

Question 19

difference between the vacuoles in an animal cell and in a plant cell

Answer 19

animal cell: numerous small vacuoles
plant cell: large central vacuole

Question 20

function of a mitochondrion

Answer 20

converts oxygen and nutrients into energy through cellular respiration
this energy can be used by the cell to perform cell activities such as growth and reproduction

Question 21

what is the green pigment in chloroplasts called?

Answer 21

chlorophyll

Question 22

are centrioles present in both plant and animal cells?

Answer 22

centrioles are only present in animal cell.
the plant cell does not contain centrioles

Question 23

describe the structure of a root hair cell and how it is adapted to function

Answer 23

The root hair cell has a long and narrow root hair. This increases the surface area to volume ratio of the cell. Water and mineral salts can be absorbed at a faster rate.

Question 24

describe the structure of a red blood cell and how it is adapted to function

Answer 24

The red blood cell contains HAEMOGLOBIN. Haemoglobin binds to oxygen and transports it round the body.
It has a CIRCULAR, BICONCAVE shape. This increases the surface area to volume ratio. It can take in and release oxygen at a faster rate. It also LACKS A NUCLEUS. This enables the cell to store more haemoglobin for transport of oxygen.

Question 25

describe the structure of xylem vessels and how it is adapted to function

Answer 25

Xylem vessels are long hollow tubes extending from the roots to the leaves. They are narrow and have no cross walls to obstruct water flow through the lumen. They do not have protoplasm to offer resistance to water flow. Their walls are thickened with lignin to prevent collapse of the vessel.

Question 26

is a leaf a cell, tissue, organ, organ system or organism?

Answer 26

organ

Question 27

is blood a simple or complex tissue?

Answer 27

complex tissue as it consists of more than one type of cell (red blood cells, white blood cells, platelets and plasma)

Question 28

are muscular tissues simple or complex tissues?

Answer 28

simple tissue