bio final

Question 1

Mitosis

Answer 1

-makes body cells
-PMAT 1x

P: sister chromosomes condense
M: chromosomes line up in the MIDDLE
A: sister chromatids pulled AWAY to poles by spindles
T: new nuclei form on each side, make 2 new cells

CYTOKINESIS: ends with 2 identical diploid cells

Question 2

Meiosis

Answer 2

-gametes (sperm/egg)
-PMAT 2x

P1: chromosome match with homologous pairs (from mom&dad), CROSSING OVER!
M1: pair at the MIDDLE
A1: pulled AWAY
T1: new nuclei form on each side to make 2 new cells
PMAT 2 same as mitosis

CYTOKINESIS: ends with 4 non-identical haploid cells

Question 3

Cell Cycle & Cell Division

Answer 3

-Interphase:
- G1: cell grows/synthesizes proteins
-Synthesis Phase: DNA replicated -> 2 sister chromatids for each chromosome
-G2: cell continues to grow/prepare for division

-M Phase (Mitosis): cell division

Question 4

Importance of Crossing Over & when it happens

Answer 4

When: Prophase I of meiosis
-create genetic variation w new combo of alleles
-evolution/adaptation

Question 5

Binary Fission

Answer 5

-asexual reproduction in prokaryotic cells

-single-celled organism divides into 2 identical daughter cells

Question 6

Complete Dominance

Answer 6

-heterozygotes have same phenotype as homozygous dominants

Question 7

Incomplete Dominance

Answer 7

-heterozygotes have an appearance that is intermediate between the phenotypes of the two homozygotes (blend of color)

Question 8

Co-Dominance

Answer 8

both alleles are expressed equally in the phenotype of the heterozygote (pink and purple colors visible)

Question 9

Transcription (location, steps)

Answer 9

-FIRST

-Location: nucleus of cytoplasm

-Initiation: RNA polymerase binds

-Elongation: RNA polymerase unzips DNA and synthesizes complementary RNA strand

-Termination: RNA polymerase detaches and RNA strand released

Question 10

Translation (location, steps)

Answer 10

-SECOND

Location: Ribosome (make protein)

Initiation: tRNA binds to start codon

Elongation: polypeptide chain of amino acids by reading mRNA codon

Termination: stop codon, polypeptide chain is released

Question 11

Silent Mutation

Answer 11

-no change to amino acids, codes for same protein

Question 12

Missense Mutation

Answer 12

-when there is a change in the amino acid sequence
-codes for different protein

Question 13

Nonsense Mutation

Answer 13

-change an amino acid codon to a stop codon

Question 14

Frame-Shift Mutation

Answer 14

-mutation by nucleotide deletions or insertions

Question 15

CRISPER technology

Answer 15

-add, disrupt, or change the sequence of specific genes

Question 16

GMO foods

Answer 16

-organisms that have acquired 1+ genes by artificial means

Question 17

Gene Flow

Answer 17

-Exchange of genes between populations

Question 18

Genetic Drift

Answer 18

-Random changes in allele frequency

Question 19

Bottleneck Effect

Answer 19

-Drastic population size reduction impacts diversity

Question 20

Founder Effect

Answer 20

-New populations started by a few individuals

Question 21

Natural Selection

Answer 21

-Survival and reproduction of the fittest

Question 22

Sexual Selection

Answer 22

-Traits that increase mating success

Question 23

Directional Selection (graph)

Answer 23

-outcome of natural selection (1/3)

-Favors one extreme phenotype
-1large peak

Question 24

Disruptive Selection (graph)

Answer 24

-outcome of natural selection (2/3)

-Favors two extreme phenotypes
-2 large peaks “M” shape

Question 25

Stabilizing Selection (graph)

Answer 25

-outcome of natural selection (3/3) - Favors intermediate phenotypes -very tall/narrow graph -majority of phenotype is only one type, not much of other phenotypes shown

Question 26

Exponential Growth

Answer 26

-Rapid population increase; unsustainable long-term -Represents ideal, unlimited growth

Question 27

Logistic Growth

Answer 27

-Population stabilizes at carrying capacity -Accounts for real-world resource limits and competition, making it more applicable to natural populations

Question 28

Density-Dependent Factor

Answer 28

-population-limiting factor whose effects intensify as the population increases in density -Competition, limited food supply. limited territory

Question 29

Density-Independent Factor

Answer 29

-population-limiting factor whose intensity is unrelated to population density -natural disasters: fires, flood, storms

Question 30

Ecological Footprint

Answer 30

-Measure human impact on ecosystems

Question 31

Biological Control

Answer 31

-Use natural predators or parasites to manage pests (e.g., ladybugs for aphid control)

Question 32

Biodiversity

Answer 32

- The variety of life at genetic, species, and ecosystem levels IMPORTANCE: -Provides ecosystem goods, services, and psychological benefits THREATS: -Habitat loss, overharvesting, pollution, and climate change. -Loss of keystone species disrupts ecosystems EFFORTS: -Establish protected areas. -Reduce human impact through sustainable practices. ETHIC: -responsibility to prevent extinction -Practical benefits for medicine, food, and ecosystem stability