DC BIO FINAL- Unit 3: Microview Test Review

Question 1

Functions of the Cell Membrane

Answer 1

The cell membrane is a phospholipid bilayer with embedded or attached proteins that separate the internal contents of the cell from the surrounding environment

Question 2

Fluid Mosaic Model

Answer 2

S.J Singer & Garth made a new model of plasma membrane or structure that better explains both microscopic observations & function of the plasma membrane

Question 3

Passive Transport

Answer 3

Molecules move from high to low concentration. No ATP is required.

Question 4

Active Transport

Answer 4

Molecules move from low to high concentration, concentrating molecules in and out of the cell. Requires ATP

Question 5

Diffusion

Answer 5

Passive process of transport. Single substances move from high to low concentration until concentration is equal across the space.

Question 6

Facilitated diffusion

Answer 6

Type of passive transport where molecules move across a cell membrane from high to low area of concentration with the help of special proteins.

Question 7

Osmosis

Answer 7

Movement of free water molecules through semipermeable membrane according to waters concentration gradient across membrane.

Question 8

Endocytosis including Phagocytosis and Pinocytosis

Answer 8

Endo: Move materials INTO cell in vesicle
Phag: “Cellular eating”
Pino: “Cellular drinking”

Question 9

Exocytosis

Answer 9

Particles enveloped in the membrane fuse with the interior of the plasma membrane. Moves large materials OUT of the cell in a vesicle

Question 10

Cell Surface-to-Volume Ratio

Answer 10

Relationship between two. Affects how efficiently a cell can exchange, materials with its environment

Question 11

Binary Fission (Signaling)

Answer 11

Asexual reproduction, a single organism (bacteria) splits into two identical daughter cells. Involves duplicates of organisms, genetic material, and division into two cells

Question 12

Histones/Nucleosomes

Answer 12

H: Proteins found in cell nuclei. Helps package and organize DNA into structural units
N: Basic Structural units of chromatin, consisting of segments of DNA, help organize & condense DNA. It makes it manageable within the cell.

Question 13

Chromatin vs. Chromosomes

Answer 13

Chromatin: Complex of DNA and Proteins found in nucleus. Packages DNA and regulates gene expression
Chromosomes: Structures made of DNA & proteins that carry genetic information and ensure accurate distribution during cell division

Question 14

Sister Chromatids

Answer 14

Identical copies of chromosomes formed during DNA replication, joined at the centromere & separate during cell division

Question 15

Homologous Chromosomes

Answer 15

Pairs of chromosomes have the same structure and genes but different alleles. Play a key role in genetic diversity during meiosis

Question 16

Diploid vs. Haploid

Answer 16

Diploid: 2 sets of chromosomes (2n)
Haploid: 1 set (n) for sexual reproduction

Question 17

Cell Cycle- Interphase (3 parts)

Answer 17

G1: Grows in size and separates or differentiates, does its job
S Phase: Synthesize of DNA, if the cell is given a signal to divide it enters the S phase, and all DNA is replicated
G2: Includes completion of cell growth and prepares for mitosis

Question 18

Phase & events of mitosis
1. Prophase

Answer 18

1. Prophase: Chromatin condenses into visible chromosomes, nuclear membrane begins to break down, spindles start to form, centrosomes move to opposite sides of the cell

Question 19

Phase & events of mitosis
2. Metaphase

Answer 19

2. Metaphase: Chromosomes line up in the center of the cell, spindle fibers attach to centromeres of chromosomes

Question 20

Phase & events of mitosis
3. Anaphase

Answer 20

3. Anaphase: Sister chromatids are pulled apart by spindle fibers & move to opposite ends of the cell, Separation ensures each new cell will receive an identical set of chromosomes

Question 21

Phase & events of mitosis
4. Telophase

Answer 21

4. Telophase: Chromosomes arrive at poles & begin to de-condense back into chromatin, nuclear membrane reforms around each set of chromosomes, spindle fibers disassemble

Question 22

Cell Cycle- Cytokinesis

Answer 22

Cytoplasm divides, resulting in 2 separate daughter cells each with its own nucleus & complete set of chromosomes.

Question 23

Meiosis

Answer 23

Sexual reproduction requires fertilization and produces four unique daughter cells each with half the number of chromosomes as the original cell, produces gametes (sperm & egg)

Question 24

Phase and events of meiosis
1 Prophase I:

Answer 24

1 Prophase I: Chromosomes condense and pair up with homologous partners forming tetrads. Crossing over occurs when homologous chromosomes exchange DNA, the Nuclear membrane breaks down, and spindle fibers start to form

Question 25

Phase and events of meiosis
2. Metaphase I

Answer 25

2. Metaphase I: Homologous chromosomes pair and line up along the metaphase plate (middle)
   Spindle fibers attach to centromeres at each homologous chromosome

Question 26

Phase and events of meiosis
3. Anaphase I

Answer 26

3. Anaphase I: Homolgus chromosomes are pulled apart & move to opposite sides of cell, SIster chromatids remain attached

Question 27

Phase and events of meiosis
4. Telophase I/Cytokinesis

Answer 27

4. Telophase/Cytokinesis: Chromosomes arrive at poles & cell divides into 2 haploid cells, each new cell has half of the original number of chromosomes. still consist of sister chromatids

Question 28

Mitosis vs. Meiosis

Answer 28

Function: Mitosis creates identical body cells; Meiosis creates genetically diverse gametes
Outcome: Mitosis results in 2 diploid cells; Meiosis results in 4 haploid cells
Genetic Diversity: Present in meiosis, absent in mitosis

Question 29

Three factors creating variety associated with meiosis

Answer 29

1. Crossing over
2. Independent assortment
3. Random fertilization

Question 30

DNA Structure

Answer 30

Double helix,
Neclotides (phosphate group, deoxyribose sugar, nitrogenous base)
Nitrogenous bases (A, T, C, G)
Base Sequence

Question 31

DNA Replication

Answer 31

This means making an exact copy. It is semiconservative, Genetic information is passed on to daughter cells.

Question 32

DNA Helicase

Answer 32

Unwinds DNA by breaking hydrogen bonds between base pairs. Creates single-stranded DNA

Question 33

DNA Polymerase

Answer 33

synthesizes new DNA strands by adding nucleotides complementary to the template strand

Question 34

DNA Ligase

Answer 34

Permentaly joins DNA fragments by forming bonds between nucleotides when sticky ends come together

Question 35

Semi conservative Replication

Answer 35

Each new molecule of DNA has an original strand & one new strand, each parental strand acts as a template for new strands

Question 36

Point mutations

Answer 36

Type of genetic mutation involves a change in a single nucleotide base pair in DNA sequence, can occur during DNA replication or environmental factors

Question 37

DNA vs RNA Structure

Answer 37

Uracil instead of Thymine, Ribose sugar instead of deoxyribose sugar, single-stranded instead of double

Question 38

Introns vs. Exons

Answer 38

Introns and exons are segments within a gene.
Exons: Coding sequences that remain in the mRNA after processing and are expressed as proteins.
Introns: Non-coding sequences removed during RNA splicing and do not code for proteins.

Question 39

Transcription

Answer 39

Creating an RNA copy of a DNA sequence, which is the first step in gene expression

Question 40

Translation

Answer 40

mRNA is converted to proteins, occurs in the cytoplasm at the ribosome
1. Initiation: The ribosome assembles at the mRNA’s start codon, and the first tRNA brings in methionine.
2. Elongation: The ribosome reads each mRNA codon, and tRNAs bring in matching amino acids, which are linked to form a growing protein chain.
3. Termination: The ribosome reaches a stop codon, releasing the completed protein, and disassembles it from the mRNA.

Question 41

Codons

Answer 41

Set of 3 RNA nucleotides (bases)

Question 42

Anticodons

Answer 42

sequences of three nucleotides on a tRNA molecule that are complementary to mRNA codons. Ensure the correct amino acid is added to the growing protein by matching each codon on the mRNA during translation