Final Review Flashcards

Question

Explain the role enzymes play in cells

Answer 1

Organic molecules made of protein or ribonucleic acid (RNA) Catalyst – substance that speeds up a chemical reaction but is not changed permanently in the chemical reaction Lowering the activation energy – energy required to disassemble the atoms in a molecule so they can recombine to form a new molecule Highly specific – will only catalyze certain chemical reactions Enzyme – substrate Catalase – hydrogen peroxide Amylase – starch DNA Polymer – Nucleotide

Answer 2

Interphase – G = Gap; S = Synthesis G1 – cell increases in size; intense metabolic activity S – DNA Replication G2 – cell prepares for cell division (produce new organelles) Mitosis – division of the nucleus Cytokinesis – division of cytoplasm Interphase

Answer 3

Prophase Chromosomes coil and become visible Centrioles separate and move to opposite polls Nuclear membrane disappears Metaphase Chromosomes line up in the center of the cell Anaphase Chromatids separate and move to opposite polls Telophase Chromosomes uncoil and become invisible Nuclear membrane reappear

Answer 4

``` Prophase I Chromosomes coil and become visible Homologous chromosomes pair up Centrioles separate and move to opposite polls Nuclear membrane disappears Metaphase I Homologous chromosomes line up in the center of the cell in pairs Anaphase I Homologous chromosomes separate and move to opposite polls Telophase I Chromosomes uncoil and become invisible Nuclear membrane reappear Interkinesis Cytoplasm separates the 2 new cells Prophase II Chromosomes coil and become visible Centrioles separate and move to opposite polls Nuclear membrane disappears Metaphase II Chromosomes line up in the center of the cell Anaphase II Chromatids separate and move to opposite polls Telophase II Chromosomes uncoil and become invisible Nuclear membrane reappear ```

Answer 5

Haploid cells – a set of chromosomes (sperm or egg cell) – 23 chromosomes Diploid cells – 2 sets of chromosomes (sematic or body cell) – 46 chromosomes

Answer 6

Animal – plasma membrane pinches inward to separate the cytoplasm of the two new cells Plants – a cell plate forms in the middle of the cytoplasm to separate the two new cells

Answer 7

Mitosis – parent or mother cell forms two daughter cells each containing the same number of chromosomes as the parent or mother cell Meiosis – parent or mother cell forms 4 daughter cells each containing half the number of chromosomes as the parent or mother cell

Answer 8

Asexual – single parent gives rise to an offspring; a clone of the parent. Sexual – single cell produced by two different parents (male and female) combine to form a zygote (fertilized egg). Zygote develops into an offspring.

Answer 9

RNA uses the nucleotide strands of DNA to first transcript, then translate the nucleotides into amino acids forming proteins

Answer 10

``` Deoxyribonucleic Acid (DNA) – (Structure) Double helix – made of two strands of nucleotides that coil about a common axis ``` The sides of the DNA molecule are composed of the phosphate and 5 carbon sugar (deoxyribose – C5 H10 O4) The steps are made of the complimentary nitrogenous bases and hydrogen bonds that join them according to the DNA base pair rule. Adenine forms a double hydrogen bond with thymine Guanine forms a triple hydrogen bond cytosine The two strands are anti parallel – they run side by side but in different directions Sense strand – 5’ to 3’ Anti-sense strand – 3’ to 5’ (Function) – Ensure the preservation of the species through DNA replication; controls metabolism and reproduction through protein synthesis Ribonucleic Acid (RNA) – (Structure) the same as DNA with two major differences. The pyrimidine base uracil replaces thymine and ribose (C5 H10 O5) replaces deoxyribose (Function) – Protein synthesis, transcription of DNA to mRNA, and translation of mRNA to Protein (amino acids)

Answer 11

Transcription – DNA (nucleotide) to mRNA (nucleotide) RNA polymerase – separates the DNA molecule in the region called the gene (functional unit of DNA) to form a protein RNA polymerase adds new nucleotides to the exposed nucleotides on the 3’ to 5’ strands of DNA according to the modified DNA base pair rule The result is a single strand of messenger RNA (mRNA) Translation - mRNA (nucleotide) to Protein (Amino Acid) mRNA combines with the Ribosomes exposing 3 sites – A site, P site, E site. The anti-codon of the tRNA forms a complex with the codon of the mRNA initially on the P site. The tRNA molecules with an Amino Acid enters on the A site. The amino acid of the tRNA molecules on the A and P site combine and move to the P site The tRNA without an amino acid leaves on the E site. Each tRNA molecules advances on codon until a “stop” codon is read and a protein or polypeptide is formed.

Answer 12

Messenger ribonucleic acid (mRNA) – carries genetic information from DNA to the ribosomes Transfer ribonucleic acid (tRNA) – carries a single amino acid Ribosomal ribonucleic acid (rRNA) – along with protein forms the ribosome

Answer 13

DNA is the molecule that carries heredity information for all living things DNA ensures the preservation of the species through DNA replication and controls metabolism and reproduction through protein synthesis

Answer 14

Point mutation – single nucleotide base substitution, insertion, or deletion of the genetic material, DNA or RNA Frameshift mutation – result of a deletion or addition of a single pair of nucleotides

Answer 15

Silent Mutation – exchange in a single pair of nucleotides results in the insertion of the same amino acid in the protein Missense Mutation – exchange in a single pair of nucleotides results in the insertion of a different amino acid in the protein Nonsense Mutation – exchange in a single pair of nucleotides results in the insertion of a termination sequence (“stop”) in the DNA code. Always lethal.

Answer 16

Mutagen – agents that cause a change in the DNA (viruses, chemical, radiation) Natural Selection – the environment selects some favorable traits to survive and reproduce while the unfavorable traits die out Evolution – a change in the population over time Some mutated genes would die off during natural selection because they are unfavorable while favorable ones would survive and reproduce. Over the course of time those favorable ones would become common place.

Answer 17

Law or Principles of Dominance – when two contrasting (different) traits are crossed, the dominant trait appears in the 1st generation (F1) Law of segregation – each parent has two factors (genes) coding for a trait which separates during gamete formation Law of independent assortment – alleles (alternative forms of a gene) separate independently during gamete formation

Answer 18

Dominant – always expressed when present (symbolized with a capital letter); dwarfism (heterozygous), Huntington disease (homozygous dominate, heterozygous) Recessive – may be hidden behind a dominate but still present (symbolized with lower case letter); albinism (homozygous recessive), Tay Sachs (hr), PKU (hr), Incomplete dominance – both forms of a trait appear in the phenotype (blended). Ex. Red flower crossed with white flower = Pink flower. Codominance – both forms of an allele (trait) are exposed (present) in the phenotype (not blended). Ex. Red cow crossed with white cow = roan cow Sex linked traits – passed from mother to son because of the link to the X sex chromosome. Colorblindness – (recessive) inability to discriminate between certain colors Duchenne’s Muscular Dystrophy – (recessive) deterioration of muscles gradually over a period of time

Answer 19

members of the same species living in a defined area

Answer 20

Natural selection – the environment selects some favorable traits to survive and reproduce while the unfavorable traits die out Artificial selection – breeder selects desirable traits to mate and produce the next generation

Answer 21

Natural Selection in Evolution – traits are inherited by offspring, and those which provide a reproductive benefit become more prevalent in a population over time. Speciation is the process by which one species becomes two which can no longer interbreed. This happens due to reproductive isolation and the passage of a great deal of time, during which their populations accumulate many genetic changes between them and become two distinct species.

Answer 22

Genetic engineering changes natural selection to artificial selection taking away the environments ability to choose which traits are favorable and should survive. Through genetic engineering, humans may desire specific traits to be favorable and loss traits they deem unfavorable that may actually be necessary for future survival

Answer 23

organism that contains genetic material into which DNA from an unrelated organism has been artificially introduced

Answer 24

Taxonomy – science that names and groups living things Domain – Kingdom – Phylum – Class – Order – Family – Genus - Species

Answer 25

Domain – (Largest group) group of similar kingdoms Arcadia – prokaryotic cells Bacteria – prokaryotic cells Eukarya – Eukaryotic cells (Protista, Fungi, Plants, Animalia)

Answer 26

``` Domain – group of similar kingdoms Kingdom – group of similar phyla Phylum – group of similar classes Class – group of similar order Order – group of similar families Family – group of similar genus Genus – group of similar species Species – individuals of the same king (smallest group) ```

Answer 27

``` Arcadia Cells lack nuclei (prokaryotic) Most are unicellular Bacteria Cells lack nuclei (prokaryotic) Most are unicellular Eukarya Cells contain nuclei (eukaryotic) Unicellular or multicellular ```

Answer 28

``` Protista Unicellular or multicellular Autotrophs (make their own food) or heterotrophs (cannot make their own food) Animalia Multicellular Heterotrophs (by ingestion) No cells walls Motile – capable of motion Fungi Most are multicellular Heterotrophs (by external ingestion) Non-motile Plantae Cell walls composed of cellulose Multicellular Autotrophs Non-motile ```

Answer 29

Symmetry – Bilateral or radial Segmentation – can the body be separated into repeated parts Appendages – are there any Body Cavity – Exoskeleton, endoskeleton, or none Reproduction – direct development (no larval stage) or indirect development (larval stage) Embryonic development – look at embryos to determine clues to evolutionary relationships Cell and tissue organization

Answer 30

Ecosystem function - the structural components of an ecosystem (vegetation, water, soil, atmosphere and living components) and how they interact with each other

Answer 31

Abiotic – non-living components; water, air, temperature, rocks and minerals that make up the soil Biotic – living components Producers – autotrophs – can make their own food (most energy and largest number of individuals) Ex. Bacteria, plants, algae Consumers – heterotrophs – cannot make their own food Herbivores – feed mostly on producers Carnivores – feed primarily on herbivores or other carnivores Omnivores – eat both producers and animals Decomposers – recyclers; convert living matter into inorganic matter; Bacteria and Fungi Species – Individuals of the same kind Population – members of the same species living in a defined area Community – different species interacting in a particular area

Answer 32

Producers – autotrophs – can make their own food (most energy and largest number of individuals) Ex. Bacteria, plants, algae Consumers – heterotrophs – cannot make their own food Herbivores – feed mostly on producers Carnivores – feed primarily on herbivores or other carnivores Omnivores – eat both producers and animals Predators – organism that eats another organism Prey – organism which is eaten by the predator Ex. Lion and zebra; bear and fish; fox and rabbit Decomposers – recyclers; convert living matter into inorganic matter; Bacteria and Fungi

Answer 33

3 linked food chain = Producer – Primary Consumer – 2nd order consumer – 3rd order consumer 4 linked food chain = Producer – Primary Consumer – 2nd order consumer – 3rd order consumer – 4th order consumer

Answer 34

Ecosystem – communities interacting with abiotic factors (non-living components); temperature, precipitation, light Community – different species interacting in a particular area Species – individuals of the same kind

Answer 35

Density independent factors – no relationship to the number of individuals in the area (fire, earthquake, flood) Density dependent factors – relates to the number of individuals in the area (competition for food, space, mating)

Answer 36

Living together; members of two different species interacting together

Answer 37

Parasitism – partnership between two different species; only the parasite receives a benefit and the host is harmed. Tapeworms attach themselves to the insides of the intestines of animals such as cows, pigs, and humans. They get food by eating the host's partly digested food which deprives the host of nutrients. Mutualism – partnership between two different species; neither is harmed and both receive a benefit. The tick bird and the rhinoceros. The tick bird eats ticks and other parasites that live on the rhino providing food while the rhino gets cleaned and pest control. When there is danger, the tick birds fly upward and scream a warning for the rhino. Commensalism – partnership between two different species; only the commensal receives a benefit but neither the host or commensal is harmed. Barnacles rely on currents to bring food past them in order to eat. Some attach themselves to various sea life, such as whales, receiving transportation all over the ocean, exposing them to more currents and feeding opportunities. The whale receives no benefit or harm.

Answer 38

Biodiversity reflects the number, variety and variability of living organisms Humans play an important role in biodiversity because the actions of humans, such as polluting the air with fossil fuels, the water and soil with waste, lowers the number of living organisms on the planet, thereby lowering the biodiversity. The lower the biodiversity the less food, clean water, and increased risk of natural disasters.

Answer 39

Water = Water vapor – condensation (cold) – liquid water – evaporation (heat) – water vapor Carbon = carbon dioxide in the air – photosynthesis (plant, algae, bacteria) – food – cellular respiration – carbon dioxide in the air Nitrogen = Fixation – Nitrification – Assimilation – Ammonification – Denitrification Fixation – bacteria changes nitrogen into ammonium Nitrification – ammonium is changed into nitrates by bacteria which are then absorbed by plants Assimilation – Plants absorb nitrates from the soil into their roots and use it in amino acids, nucleic acids, and chlorophyll Ammonification – Decaying process. Plants or animals die, decomposers like fungi and bacteria turn the nitrogen back into ammonium for it to reenter the nitrogen cycle Denitrification – Extra nitrogen in the soil gets put back out into the air by bacteria