A2.2 HL only

Question 1

protocells

Answer 1

self-organized, endogenously ordered, spherical collection of lipidsproposed as a rudimentary precursor to cells

Question 2

infolding

Answer 2

the folding in of an outer layer so as to form a pocket in the surface

Question 3

endosymbiosis

Answer 3

two organisms living together with one inside the other

Question 4

internal membranes

Answer 4

egulates the passage of nutrients, metabolites, macromolecules, and information in and out of the cytoplasm and maintains the proton motive force required for energy storage

Question 5

Compartmentalization

Answer 5

the separation of the cell interior in distinct compartments with specific local conditions that allow the simultaneous occurrence of diverse metabolic reactions and processes

Question 6

mitochondria

Answer 6

a round to oval-shaped organelle found in the cells of almost all eukaryotic organisms. It produces energy, known as ATP

Question 7

chloroplasts

Answer 7

an organelle within the cells of plants and certain algae that is the site of photosynthesis

Question 8

endocytosis

Answer 8

the process by which cells take in substances from outside of the cell by engulfing them in a vesicle

Question 9

aerobic bacteria

Answer 9

bacteria that can grow and live when oxygen is present

Question 10

photosynthetic bacteria

Answer 10

Bacteria that can utilize sunlight to produce their food

Question 11

Endosymbiotic theory

Answer 11

proposes that mitochondria originated as free-living Alphaproteobacteria that were internalized by a pre-eukaryotic host cell, leading to the formation of the modern eukaryotic cell

Question 12

endocytosis

Answer 12

the process by which cells take in substances from outside of the cell by engulfing them in a vesicle

Question 13

binary fission

Answer 13

the process of one cell simply dividing into two

Question 14

Genome

Answer 14

the entire set of DNA instructions found in a cell

Question 15

Housekeeping genes

Answer 15

a set of genes that are constitutively expressed in cells and are essential for basic cellular functions

Question 16

Differentiation

Answer 16

the process where less specialized cells undergo changes to develop specialized structures and functions

Question 17

expressed

Answer 17

the process by which the information encoded in a gene is turned into a function. This mostly occurs via the transcription of RNA molecules

Question 18

Stem cells

Answer 18

cells with the potential to develop into many different types of cells in the body

Question 19

spermatogonium

Answer 19

an undifferentiated male germ cell

Question 20

spermatids

Answer 20

a product of the second meiotic division that undergoes a complex process of morphological and functional changes known as spermiogenesis

Question 21

mature sperm cells

Answer 21

a spermatozoa, which is formed by meiosis and is haploid in nature

Question 22

zygote

Answer 22

fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm)

Question 23

Totipotent

Answer 23

the ability of a single cell to divide and produce all the differentiated cells in an organism, including extraembryonic tissues

Question 24

Pluripotent

Answer 24

A cell that is able to develop into many different types of cells or tissues in the body

Question 25

Multipotent

Answer 25

the cell’s ability of self-renewal and developing into multiple specialized cell types present in a particular tissue or organ

Question 26

Unipotent

Answer 26

capable of developing into only one type of cell or tissue

Question 27

Blastocyst

Answer 27

an early embryonic structure formed after the fertilization of an egg

Question 28

Embryo

Answer 28

Early stage in the development of humans and other animals or plants

Question 29

Skin stem cells

Answer 29

multipotent adult stem cells present in the adult skin, which can self-renew and differentiate into different cell lineages of the skin

Question 30

Tissue

Answer 30

a group of cells that have similar structure and that function together as a unit

Question 31

Organs

Answer 31

a group of tissues in a living organism that have been adapted to perform a specific function

Question 32

Organ systems

Answer 32

a biological system consisting of a group of organs that work together to perform one or more functions

Question 33

Melanin

Answer 33

a substance in your body that produces hair, eye and skin pigmentation

Question 34

Shoot apex

Answer 34

the tip of the stem, which contains meristematic cells and the region of growth

Question 35

photoperiod

Answer 35

the physiological reaction of organisms to the length of light or a dark period

Question 36

multicellularity

Answer 36

an organism composed of many cells

Question 37

Aggregation

Answer 37

a group of organisms of the same or different species living closely together but less integrated than a society

Question 38

biofilms

Answer 38

a community of microorganisms attached to an inert or living surface by a self-produced polymeric matrix or an assemblage of microbial cells associated with a surface and enclosed in a matrix of primarily polysaccharide material

Question 39

Daughter cells

Answer 39

the cells that are formed after cell division

Question 40

Volvox

Answer 40

polyphyletic genus of chlorophyte green algae in the family Volvocaceae. Volvox species form spherical colonies of up to 50,000 cells

Question 41

somatic (body) cells

Answer 41

any biological cell forming the body of a multicellular organism other than a gamete

Question 42

gonidia

Answer 42

an asexual reproductive cell or group of cells especially in algae (such as volvox)