Evolution and Genetics - AP Biology

As this is recessive epistasis, only the genotype aa will mask gene B (Aa will not mask B). BB or Bb will give the dominant phenotype as B is dominant to b. Thus, AaBb will yield the dominant phenotype.

Autosomes are all the chromosomes that do not determine an individual's sex. X and Y chromosomes both determine sex, and are sex chromosomes. The other 22 pairs of chromosomes are autosomes.

Gregor Mendel studied genetics through the crossbreeding of pea plants. Through his studies, he proposed laws of heredity (the law of segregation, the law of independent assortment, and the law of dominance), that are now called the laws of Mendelian inheritance. Darwin famously studied finches on the Galapagos Islands.

The union of two gametes is called fertilization, which results in a zygote. The zygote is a diploid cell that will grow into the entire organism.

Evolution is any change in the proportions of different genotypes in a population from one generation to the next. Mutation, geneflow, nonrandom mating, and natural selection all contribute toward favoring certain alleles over others within a population. This leads to changes in allele frequency, and subsequent evolution.

It is believed that sponges were the first animals to utilize multicellularity. Sponges only have a few cell types, including: choanocytes, porocytes, and pinacocytes. Choanocytes have flagella that beat continuously to move water, and microvilli, which are specialized for absorbing nutrients. Porocytes are tubular cells that form the pores of sponges. Pinacocytes produce collagen and provide structural support to the sponge. Although algae likely developed multicellularity early on, they are not animals. Arthropods and mammals are both multicellular and animals, but evolved after sponges.

Lamarck incorrectly believed that parents could pass on traits that they had acquired to their offspring. He believed that the changes made during a lifetime, such as increased muscle mass, would be passed on to offspring. This is not true since acquired traits, except on very few rare occasions, do not affect the DNA. For example, if two parents have small muscles, but then take steroids and become bodybuilders, their offspring will still inherit the small muscle genes, since only the muscles, not the DNA is affected by bodybuilding.

When a thermal neutron collides with a nitrogen atom in the atmosphere, it causes a proton to fly off from the atom, reducing the atom from nitrogen to carbon while keeping the same number of neutrons, 14. Because the amount of matter in the universe is believed to be constant, we can measure the amount of carbon-14 left in a dead specimen to determine its age within approximately 50,000 years.

Coprolites are fossilized fecal matter from an animal. By studying their contents, biologists can gather information on what the animal ate, and what species were there to be eaten by the animal.

Carbon-14 dating is used to date organic material within an approximately 50,000 year time period, due to the relatively short half life of the carbon-14 isotope. Other isotopes are used to date the rocks surrounding dinosaur fossils, such as in the uranium-lead method or the potassium-argon method.

The key to answering this question is organic material. Once an organism dies, it ceases to participate in carbon exchanges with the atmosphere. What carbon is left in the organism then decreases at a stable rate which allows scientists to reliable date the era that the organism died in.

Zygote mortality is an example of post-zygotic reproductive isolation. In this type of reproductive isolation, gametes from two species may fuse, however the zygote is inviable shortly after fertilization due to improper development.

Lamarck theorized that animals evolved into new forms based on need or utility, and thus he is the correct answer for this question.

Darwin was the father of the theory of evolution by natural selection (along with Alfred Russell Wallace), Watson and Crick discovered the structure of DNA (along with Rosalind Franklin), Leeuwenhoek pioneered microscopy, and Jonas Salk created the polio vaccine, so none of those are correct.

The principal of use and disuse suggests that organs you use get bigger while those you don't use get smaller or even disappear entirely. Inheritance of acquired characteristics sugegsts that proficiencies and traits can be passed down to succeeding generations. Lamarckian evolution is largely based on these two ideals.

Theory of genetic chance is not a real foundation of Lamarckian evolution.

While Lamarck had many revolutionary ideas on evolution, his most correct assumption was the importance of environmental changes on evolutionary adaptations. His theories on the inheritance of acquired traits and essentialsm do not fit into our current knowledge of evolution, DNA, and inheritance.

The theory of inheritance of acquired characteristics was one of the earliest theories of evolution. Lamarck believed that traits were passed down to offspring when the parent showed increased use of those traits, and that traits that were not used by the parent were not inherited. The most common example of this "use and disuse" idea was a giraffe that, during its lifetime, often stretched its neck to reach leaves, and thus had a greater number of offspring with long necks.

This theory was shown to be incorrect in favor of Darwin's theory of evolution by natural selection. Use or disuse during an organism's lifespan is not the driving force of evolution.

Lamarck hypothesized, amongst other things, that organisms could pass down traits acquired during life from generation to generation. Under Lamarck's theory of use and disuse, a man who worked in a factory and developed strong arms would pass the strong arms trait to his offspring. This hypothesis has largely been rejected by modern genetics.

Gregor Mendel is the founder of modern genetics, developing our modern understanding of allelic inheritance. Charles Darwin developed important theories about evolution and natural selection. Carolus Linnaeus is best remembered for establishing binomial nomenclature, the system used today to officially name organisms.

Jean-Baptiste Lamarck was an evolutionary theorist who was rejected by Charles Darwin. In his theory, Lamarck supported the idea that individuals could pass down acquired characteristics to their offspring, and that they lost un-needed traits and gained useful traits. The most recent theory of evolution, like Charles Darwin, rejects these claim.

Hybrid sterility is an example of post-zygotic reproductive isolation. In the case of hybrid sterility, hybridization can occur between two species, however the resulting hybrids are unable to produce; the hybrids are sterile.

Gregor Mendel's famous work on pea plants built our first understandings of inheritance. He identified that "discrete particles", which we now call genes and alleles, are passed to offspring in numerous of combinations. These different combinations create variation in a population.