MCAT Biology: Systems EK Exam Questions with Complete Solutions

Protista, Fungi, Plantae, and Animalia all fall under domain? - AnsEukarya All mammals belong to the class ____________ and the phylum _________. - AnsMammalia; Chordata Define the cell theory - Ans The cell is the smallest basic unit of life and is shared by all living things. The average eukaryotic cell is __________ Mm - Ans10-100 What is the difference between genotype and phenotype? - AnsGenotype= chromosomes of an organism phenotype= the product of genes What are alleles? - AnsA form of gene. I.e white flower gene (allele 1) purple flower gene (allele 2) Same gene, diff colors. A gene that has multiple alleles, with different phenotypes is called? - Anspolymorphism The __________ _________ is the total of all alleles in a population and _____________ is a change in a population's gene pool. - Ansgene pool; evolution What is speciation? - AnsThe formation of a new species What mechanisms contribute to speciation? - Ans1. Inbreeding (mating of relatives) 2. Bottleneck ( differences of allelic frequencies between populations) 3. Specialization and adaptation How does inbreeding contribute to speciation? - AnsWhen relatives mate, it increases the homozygous individuals in a population without changing the allele frequency, if the population is geographically divided into groups and a mutation arises in one group but not the other than it leads to speciation. What is outbreeding? - AnsMating between non-relatives, maintains genetic flow What is the bottleneck theory? - Ansreduction in the size of a population due to environmental events ( earthquakes, floods, fires, etc) In what conditions would evolution fail to occur according to Hardy-Weinberg equilibrium? - Ans1. mutational equilibrium 2. large population 3. random mating 4. immigration or emigration must not change the gene pool 5. No selection for the fittest organism How can evolution be measured? - Ansby gradual random changes in the genome What is genetic drift? - Ansone allele may be permanently lost due to the death of all members having that allele Natural selection is how well an organism can reproduce to contribute its genes to the next generation. How does this occur? - Ansdifferential reproduction (living beyond reproduction in order to give offspring a better chance to reproduce) What is the protein coat of viruses called? - Anscapsid A mature virus outside the host cell is called a - Ansviral particle or virion How do viruses reproduce? - AnsThey uses ATP from the cytosol and mitochondria, and it uses the ribosomes in the cytosol to make proteins and enzymes to reproduce.