Bio test 3

Are fungi more closely related to plants or animals? Describe a few characteristics of fungi to support your answer.

Are fungi more closely related to plants or animals? Describe a few characteristics of fungi to support your answer.

Fungi are more like animals because they are heterotrophs, different than autotrophs like plants that make their own food. Fungi have to obtain their food, nutrients, and glucose from outside sources. Also, the cell walls in many species of fungi contain chitin, while plants use cellulose. For example, mushrooms and humans store carbohydrate energy as glycogen, while plants use starch to store energy. Mushrooms also produce vitamin D when exposed to sunlight, similar to humans.

Neither plant nor animal, but genetically more similar to animals than plants. They are heterotrophs and take in oxygen and release carbon dioxide. Their walls contain chitin, just like insect shells.

A misconception some people have about evolution is illustrated in the question “If we evolve from chimpanzees, why are there still chimpanzees around?” Use your knowledge of evolution to provide a more accurate description of the relationship between humans and chimpanzees.

Evolution doesn’t say one species replaces another species. It says species change over time to adapt to their environments. We did not evolve from chimps but we come from a common ancestor as chimpanzees and evolved with different characteristics.

 What is the mechanism by which species evolve?

Natural Selection

Can you define Natural Selection?

Differential survival and reproduction of individuals in population based on differences in heritable traits.

Can individuals evolve within their own lifetime? If not, how does it occur?

Natural selection acts on individuals, but only populations evolve over generations.

Favorable traits will be passed down to offspring. If the trait is successful and continues to be passed down more of the population will have it.

Are there such things as objectively superior traits, according to evolutionary Theory?

Individual with traits that enhance survival and reproduction will have, on average, more offspring.

What is the difference between Natural Selection and Artificial Selection?

Natural selection is any selection process that occurs as a result of an organism's ability to adapt to its surroundings. Artificial selection, on the other hand, is selective breeding that is imposed by an external entity, usually humans, in order to enhance the frequency of desirable features.

Recall Adaptation. What does it mean to say a species is highly adapted?

Adaptation is the accumulation of these favorable traits in a populatio over time. If a species is highly adapted they are enhanced in survival and reporidction in their environment.

 What is reproductive isolation and why is it important for speciation to occur?

Reproductive isolation represents a breakdown in the ability to reproduce successfully with sexual partners of another type of organism, and speciation requires a build up of reproductive isolation between diverging types of organism until gene flow is sufficiently rare or ineffective that the entities are considered.

Can you give an example of directional, stabilizing, and disruptive selection?

Directional Selection- is giraffe neck lengths. The environment created a selection pressure which favored giraffes with longer necks who could reach more food in the trees.

Stabilizing Selection- An example of this is plant height. In a population of plants, those that are short may not get enough sunlight, but those that are tall may be subjected to wind damage. This results in an increase in the number of medium-height plants and a decrease in very tall and very short plants.

Disruptive Selection- the beak size of finches on the Galapagos Islands that was studied by Darwin. Because the majority of seeds found on some of the islands were either large or small, finches with large and small beaks (no medium-sized beaks) were favored on those islands.

How is biological (Darwinian) fitness determined?

Darwinian fitness- the contribution that an individual makes to the gene pool of the next generation in comparison to the contributions from other individuals.

Where do new alleles originally come from?

Mutations

 What is genetic equilibrium and what must be true for it to be occurring?

Genetic Equilibruim- no evolution occurring, no mutations, large populations, population isolated, random mating, all individual repridcue at the same rate

Give two examples of genetic drift.

Founder effect and bottleneck

What challenges do organisms face that drive evolution?

Environmental pressures or changes that organisms face are known as selective pressures. These pressures can be biotic, such as competition for resources or predation, or abiotic, such as changes in temperature or availability of water. Selective pressures can also be caused by human activities, such as habitat destruction or pollution.

When organisms face these pressures, they may undergo adaptations in order to survive and reproduce in their environment. These adaptations can be physical, such as changes in body shape or coloration, or behavioral, such as changes in mating rituals or feeding habits. Over time, these adaptations can accumulate and lead to the formation of new species or the extinction of others.

The process of evolution is driven by these selective pressures and the resulting adaptations. Organisms that are better adapted to their environment are more likely to survive and reproduce, passing on their advantageous traits to their offspring. This can lead to the gradual evolution of populations over time.

Understanding the selective pressures that organisms face can provide insights into the evolution and diversity of life on Earth. By studying how organisms have adapted to their environments, scientists can gain a better understanding of the processes that have shaped life on our planet.

What did Urey and Miller demonstrate in 1953 related to the origin of life on Earth?

They demonstrated that organic monomers can form under conditions that simulate early Earth.

What two organismal Domains belong to Prokaryotes?

Domain Bacteria and Domain Archaea

What sets Archaea apart from other microorganisms?

Cell Walls

What are the hallmark characteristics of prokaryote cell structure?

Cell walls, fagella, and capsule

Even though bacteria don't have "sex" in the way animals do, how can they transfer DNA between cells?

Bacteria reproduces by binary fission. DNA is transferred by transformations, transduction, conjugation, or plasmid transfer.

Transformation- Pieces of DNA may be taken up by other bacteria and integrated

Transduction- A bacteriogphage infects bacteria and transfer the DNA

Conjugation- the donor cell transfers a chromosome copy through a mating bridge.

• A donor cell uses a hollow extension called a sex pilus to form a physical connection to a recipient cell.

Plasmids- a small, circular DNA molecule that resides in the cytoplasm of a bacterim

• Plasmids can replicate independently of the bacterial chromosome

What two defining characteristics of life do viruses not have?

A virus has no cells and cannot reproduce on its own.

What are the two viral life cycles and how do they work?

Lytic and Lysgenic cycle

In the lytic cycle, viruses multiply in the host cell and then burst out; in the lysogenic cycle, the viral DNA inserts into the host cell DNA and remains dormant. As the bacteria replicates, the viral DNA is also copied. Eventually, the viral DNA removes itself from the bacterial DNA and becomes active again.

What special "trick" does HIV use to reproduce itself? How does it work?

To reproduce, HIV uses reverse transcriptase to convert RNA into DNA. During normal DNA expression, the host cell will then make new viral RNA. HIV “hijacks” the cell’s own DNA expression system.

What is the difference between obligate and facultative symbiosis?

Obligate symbionts are mutualists that tend to have a nutritional function and typically occur in insects that feed on imbalanced diets such as plant saps or cellulose. In contrast, facultative symbionts have a much broader array of effects, ranging from mutualism to manipulation of reproduction.

What are a few ways fungi has been helpful to humans?

Fungi have been helpful to humans in various ways. They are used to make bread, beer, and cheese. They also produce antibiotics like penicillin and are used in the production of medicine. Fungi help in the decomposition of dead plants and animals, which enriches soil. They are also used in bioremediation to clean up toxic waste.

Be able to describe a fungus using the terms: mushroom, mycelium, and hyphae.

Hyphae- The tissue that makes up a mushroom

Mycelium- The part of the fungus that is underground

Mushroom- The fruiting body of the fungus

What specialized cells do fungi use to reproduce?

Fungi use haploid cells called spores to reproduce.

Fungi use spores for reproduction. Spores are single-celled structures capable of developing into new individuals. Spores are formed through meiosis and are released into the environment. Fungi can produce spores in large or small quantities. Spores can remain dormant for long periods and survive in harsh conditions. Spores allow fungi to spread their genetic material and adapt to changing environments, ensuring their survival in various ecosystems.

What are the basic parts of a plant's body, and what do they do?

A plant has five basic parts: roots, stems, leaves, flowers, and seeds/fruits1. The roots absorb water and minerals from the soil, while the stems provide support, transport water and nutrients, and store nutrients12. Leaves are where food is prepared for the plant1. Flowers are where reproduction occurs, and seeds/fruits are the result of that reproduction.

 Do you know an example of how fungi and plants live together symbiotically?

Fungi and the roots of almost all vascular plants form mutualistic associations called mycorrhizae (singular, mycorrhiza). The fungus gets its energy from the plant, and the plant acquires an efficient nutrient absorbing mechanism—the actively growing hyphae that penetrate regions of the soil untapped by root hairs.

 A waxy cuticle, vascular tissue, seeds, and flowers are all key traits that allowed for the evolution of new types of plants. Do you know the order these traits evolved? And what kind of plant is each allowed for

Traits allowing for plant evolution: waxy cuticle, vascular tissue, seeds, flowers. Order: waxy cuticle, vascular tissue, seeds, flowers. Waxy cuticle allowed for non-aquatic life, vascular tissue for taller growth, seeds for reproduction without water, and flowers for pollination. One of the most fascinating aspects of plant evolution is the development of traits that allowed them to adapt to different environments and become the diverse group of organisms we know today. Among these traits, four stand out: the waxy cuticle, vascular tissue, seeds, and flowers, which emerged in a specific order.

In bryophytes, how are the spore capsules and the green "leafy" parts different? (hint: genetic difference)

The spore capsules and green parts in bryophytes have different genetic codes due to the process of meiosis, which leads to the formation of haploid spores in capsules and diploid cells in the green parts.

How does water move from the roots of a plant up towards the leaves?

Plants transport water and mineral ions into the roots from the soil via active transport. the xylem is a part of the plant responsible for water movement within the plant. water is moved from the roots to the leaves via transpiration pull in the xylem.

What are the male and female parts of an angiosperm plant?

The flower is the reproductive unit of some plants (angiosperms). Parts of the flower include petals, sepals, one or more carpels (the female reproductive organs), and stamens (the male reproductive organs).

What is the difference between an autotroph and a heterotroph?

Autotroph- Uses Photosynthesis to make energy

Heterotroph- Acquires emergy from other things

The difference between autotroph and heterotroph is that autotroph is an organism that can make its own food from inorganic substances using light or chemical energy, while heterotroph is an organism that has to consume organic matter produced by other organisms.

Which animal phylum frequently has "stinging cells" and can switch between two body forms?

Cnidarians contain specialized cells known as cnidocytes (“stinging cells”) containing organelles called nematocysts (stingers). These cells are present around the mouth and tentacles, and serve to immobilize prey with toxins contained within the cells. Nematocysts contain coiled threads that may bear barbs. The outer wall of the cell has hairlike projections called cnidocils, which are sensitive to touch. When touched, the cells are known to fire coiled threads that can either penetrate the flesh of the prey or predators of cnidarians (see Figure 1) or ensnare it. These coiled threads release toxins into the target and can often immobilize prey or scare away predators.

• They can have radial or bilateral symmetry.

What phylum of "worm" has an open circulatory system where blood can flow freely around the body?

In contrast to a closed system, arthropods (including insects, crustaceans, and most mollusks) have an open circulatory system. In an open circulatory system, the blood is not enclosed in the blood vessels, but is pumped into a cavity called a hemocoel. The blood is called hemolymph because it mixes with the interstitial fluid. As the heart beats and the animal moves, the hemolymph circulates around the organs within the body cavity, reentering the heart through openings called ostia (singular: ostium). This movement allows for gas and nutrient exchange.

Octopi, oysters, and snails all belong to what phylum?

Molluscans are very diverse animals and form an important part of the ecosystem in the world. Some animals that you are familiar with like snails, octopuses, squids, oysters, clams etc. all belong to Phylum Mollusca. Did you know that Molluscs with shells can produce pearls? Some of these are also eaten by humans in different regions of the world. Let us educate ourselves about this phylum of the Animal Kingdom.

Which phylum has the most individuals and the most significant number of species (by far)?

The phylum arthropods or the class Insecta which belong to the phylum Arthropoda has the most amount of species present than any other phylum all class.

 Chordates have what feature very early in embryonic development?

The chordates are named for the notochord, which is a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and in the adult stage of some chordate species. It is located between the digestive tube and the nerve cord, and provides skeletal support through the length of the body.

Most chordates are vertebrates. To be a vertebrate means you have a

Backbone

Amphibians' eggs must be surrounded by water to survive, so amphibians can never live too far from a body of water. What is different about reptile eggs that let them live and reproduce in places with little water?

Reptile eggs have hard, leathery shells, which protect the young, and they are generally laid in nests, or buried underground. Amphibians lay eggs that lack a protective membrane, and are generally found adhering to the stems of underwater plants. Amphibians fertilize eggs externally, while reptiles have internal fertilization.

• Reptile eggs are amniotic.

What are the three groups of mammals around today? Which one do we belong to?

As we found in the previous parts of this series there are three main types of mammal: monotremes, marsupials, and placental mammals.

Monotremes are members of the mammalian order Monotremata. They are the only mammals that don’t give birth to live young. Instead, they lay eggs.

Marsupial is a member of the infraclass Marsupialia. (Infraclass is an intermediate classification category that comes below class.)

• Marsupials are mammals whose young are born in a relatively undeveloped state. After being born, the young (called ‘joeys’) crawl into a special pouch in the mother’s body. Here they undergo further development, and have access to their mother’s milk.

A placental mammal is a member of the infraclass Placentalia.

• Placental mammals give birth to live young. While in the womb, the developing fetus receives nourishment from an organ called a placenta.

• Humans are placental mammals.

Within Hominid evolution, was there a single unbroken lineage that led to Homo sapiens (humans)? Or were there many that failed along the way?

Hominid evolution was sometimes pictured as a single line of descent and a steady progression from primitive forms to more advanced forms. The fossils suggested otherwise. Instead, hominid evolution produced a dense thicket of branches, with several species co-existing at any given time except for the last 30,000 years or so.

How do bacteria reproduce

Binary Fission (asexual