Unit 5 - Biology

Question 1

Cell Theory

Answer 1

• All living things are made up of +1 cells
• Cells are basic unit of life
• Cells come from pre-existing cells

Question 2

Prokaryote

Answer 2

• Cell doesn’t contain nucleus or membrane-bound organelles.
• Bacteria and archaea
• Tens to thousands of times smaller than eukaryotes

Question 3

Eukaryote

Answer 3

• Cell that contains nucleus and other organelles surrounded by thin membrane
• Protists, fungi, animals, and plants

Question 4

Organelle

Answer 4

Cell structure that performs specific function for cell

Question 5

Cytoplasm

Answer 5

• Suspends all organelles in cell and moves them around
• Mostly water, other substances cell stores until needed
• Chemical reactions take place, changing it from jelly-like to liquid

Question 6

Cell Membrane

Answer 6

• Flexible double-layered organelle surrounding cell
• Allows some substances (ex: water, oxygen) to enter, keeps others (ex: proteins) out
• “Semi-permeable membrane”

Question 7

Nucleus

Answer 7

• Roughly spherical structure containing genetic information controlling cell activities
• Stores info in chromosomes containing deoxyribonucleic acid, or coded instructions
• DNA copied when cell divides so new cell has complete DNA

Question 8

Mitochondria (s: mitochondrion)

Answer 8

• Cells store energy as glucose.
• Mitochondria contains enzymes converting stored energy for use (known as cellular respiration - requires oxygen)

Question 9

Active vs. Passive Cells

Answer 9

Active cells (muscles) have more mitochondria than others (fat-storage - may have 1-2 only) as they need faster cellular respiration

Question 10

Endoplasmic reticulum

Answer 10

• 3D branching tubes and pockets extending through cytoplasm and from nucleus to cell membrane
• Fluid-filled tubes transport material through cell

Question 11

Golgi bodies

Answer 11

• Collect materials to be removed from cell
• Make and secrete mucus.
• Cells that secrete lot of mucus (ex: cells lining intestine) have many Golgi bodies.

Question 12

Vacuole

Answer 12

• Single layer of membrane enclosing fluid in sac.
• Containing substances, removing unwanted substances from cell, maintaining internal fluid pressure (turgor) within the cell.

Question 13

Animal vs. Plant Vacuoles

Answer 13

• Animal cells have small vacuoles not visible.
• Mature plant cells have one central vacuole visible under microscope.

Question 14

Plant: Cell Wall

Answer 14

• Outside cell membrane.
• Rigid but porous structure made of cellulose.
• Holds long after plant died.

Question 15

Large Vacuole

Answer 15

• Vacuole takes most space inside cell.
• When full of water, turgor pressure keeps cells plump, keeping plant’s stems firm.
• If water level drops, vacuoles lose turgor pressure and cells become soft

Question 16

Chloroplast

Answer 16

• Plant cells exposed to light have chloroplasts
• Contain chlorophyll, absorbing light energy used in photosynthesis

Question 17

Asexual Reproduction

Answer 17

• Producing offspring from one parent cell
• Offspring is genetically identical to parent, receiving complete set of genetics

Question 18

Sexual Reproduction Details

Answer 18

• Parent cells typically have half of DNA in regular cell
• Half-cells known as “gametes”

Question 19

Cell Division

Answer 19

• Allows organisms to reproduce, grow and repair damage
• Used by all cells to reproduce

Question 20

Sexual Reproduction Process

Answer 20

• Producing offspring by fusion of two gametes
• Offspring has genetics from each parent

Question 21

Meiosis

Answer 21

Additional cell division process production of gametes entails

Question 22

Diffusion

Answer 22

• Transport for moving chemicals into and out of cell from area of higher concentration to that of lower concentration
• Chemicals enter cell across membrane to cell

Question 23

Osmosis

Answer 23

Movement of fluid across membrane toward area of high concentration

Question 24

Reason for Size of Cells

Answer 24

• Chemicals must be available to all parts of cell, in right amount of water
• Waste products must diffuse out of cell quickly
• Chemicals and water cannot move through large cells fast enough.

Question 25

Reproduction

Answer 25

Transfer of genetic information from parent to offspring.

Question 26

Cell cycle

Answer 26

• Three stages cell passes through
• Embryonic cells divide rapidly, some cells taking 30h for cycle
• Specialized cells (ex: adult nerve cells) never divide

Question 27

A: Interphase

Answer 27

• Cell in interphase for 90% of time, growing and fulfilling normal function
• Chromatin makes identical DNA, doubling self
• Centrosomes + other organelles make identical copy as well

Question 28

Chromatin

Answer 28

Long and thin strands of DNA filling nucleus

Question 29

Mitosis A: Prophase (1st stage)

Answer 29

• Chromatin twists and becomes thick and short
• Identical sister chromatid attach together to make chromosome
• Nucleolus and Nuclear Membrane disappear
• Centrosomes travel to poles

Question 30

Mitosis B: Metaphase

Answer 30

• Chromosomes line on equatorial plane (middle line)
• Centrosomes arrive at poles of cell and produce spindle fibers
• Spindle fibers attach to two sister chromatids in chromosome

Question 31

Mitosis C: Anaphase

Answer 31

• Spindle fibers pull one sister chromatid of each chromosome to each of poles
• Ensures each cell gets copy of each chromosome

Question 32

Mitosis D: Telophase

Answer 32

• Cells begin to separate
• Nucleolus and Nuclear Membrane reappear
• Chromosomes begin to unravel back into chromatin inside nuclear membrane

Question 33

Cytokinesis

Answer 33

• Cytoplasm and organelles evenly distributed between two cells
• Cell divides to form two new cells

Question 34

Body Parts by Size

Answer 34

Systems > Organ > Tissue > Cell