Cytology

Question 1

define “cell”.

Answer 1

the basic unit of all living things, responsible for carrying out all life processes

Question 2

cell membrane:

Answer 2

limits and encloses the cytoplasm and acts as a selective barrier to the movement of substances into and out of the cell. (semi-permeable)

Question 3

cytoplasm:

Answer 3

granular fluid that acts as a support for all structures within the cell.

Question 4

endoplasmic reticulum:

Answer 4

network of clear, tubular structures that allow substances & other organelles to move around

• rough ER: ribosomes
• smooth ER: no ribosomes

Question 5

ribosomes:

Answer 5

small granules in the inner surface of the endoplasmic reticulum. actual sites of protein synthesis in the cells.

Question 6

mitochondria:

Answer 6

site of food breakdown to release energy in the form of heat and adenosine triphosphate (ATP). “powerhouse of the cell”

Question 7

lysosomes:

Answer 7

cell demolition sites concerned with inner-cellular digestion.

Question 8

golgi apparatus:

Answer 8

structure located near the nucleus that collects proteins from the endoplasmic reticulum and prepares them for secretion into the cell membrane

Question 9

centrioles:

Answer 9

paired, tubular structures near the nucleus that direct the formation of the mitotic spindle during mitosis.

Question 10

nucleus:

Answer 10

organelle that controls and regulates metabolic processes. it contains all the cell’s hereditary/genetic material (chromosomes, genes and DNA). directs all cell activity, essential for reproduction

Question 11

what is DNA?

Answer 11

deoxyribonucleic acid. “blueprint” that contains instructions for building proteins.

Question 12

what are chromosomes?

Answer 12

thread-shaped bodies located in the nucleus that contain DNA. humans have 23 pair of chromosomes that house 100s of genes

Question 13

what are genes?

Answer 13

a DNA segment that carries the info for building one protein. it is responsible for physical trait like hair and eye colour, height, etc.

Question 14

define tissue:

Answer 14

a collection of cells performing a particular function .

Question 15

what are the 4 tissues of the body?

Answer 15

1. Connective tissue: support (bone, tendons, fascia, ligaments, blood, lymphatic fluid)
2. Epithelial: coverings (skin, mucous membranes)
3. Muscular: movement through contraction and relaxation
4. Nervous: control (brain, spinal cord, nerves)

Question 16

define organ

Answer 16

groups of tissue designed to perform specific functions

Question 17

define organ systems

Answer 17

groups of organs that cooperate to perform a common function

Question 18

how many organ systems in the human body? name them.

Answer 18

1. integumentary (skin)
2. respiratory
3. digestive
4. urinary
5. reproductive
6. skeletal
7. muscular
8. nervous
9. cardiovascular
10. lymphatic
11. endocrine

Question 19

define mitosis

Answer 19

asexual cellular reproduction where one parent cell splits in 2 genetically identical daughter cells (diploid cell)

Question 20

what are the phases of mitosis?

Answer 20

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Question 21

what are the functions of mitosis?

Answer 21

• growth of tissues and organs after birth
• replacement of dead cells
• repair of damaged tissue

Question 22

describe interphase

Answer 22

majority of a cell’s lifespan is spent in this phase. it is a phase of rest, growth and maturation. chromosomes are scattered throughout the nucleus.

Question 23

define homeostasis

Answer 23

the body’s ability to respond to changes in its in its environment in order to maintain stable internal conditions and function normally. a dynamic state if balance

Question 24

what is metabolism?

Answer 24

a complex chemical action whereby the body’s cells are supplied with the energy needed to function. the proper functioning of the cell.

Question 25

describe the two phases of metabolism.

Answer 25

1. anabolism: constructive metabolism, simpler substances, formed into more complex ones
2. catabolism: destructive metabolism, complex substances broken down into similar ones