biology- exam 1

What is artificial selection? How does it differ from natural selection?

Artificial selection only brings desirable changes and desirable traits and brings a decrease in genetic diversity.Natural selection affects the entire population of a species. Artificial selection only affects the selected individuals. Natural selection results in a large amount of biological diversity.

Why are patterns in the distribution of fossils and living species useful evidence of evolution?

Biogeographical patterns provide clues about how species, both alive and extinct, are related to each other. The fossil record, though incomplete, provides valuable information about what species existed at particular times in Earth's history.

Chloroplast

Convert solar energy to cellular energy and synthesize organic compounds from carbon dioxide and water

Explain crossing over and its importance.

Crossing over is the swapping of genetic material that occurs in the germ line. ... Crossing over results in a shuffling of genetic material and is an important cause of the genetic variation seen among offspring.

What are the three phases of interphase? What occurs in each phase?

G1 phase (cell growth), followed by S phase (DNA synthesis), followed by G2 phase (cell growth). At the end of interphase comes the mitotic phase, which is made up of mitosis and cytokinesis and leads to the formation of two daughter cells.

An elephant has a long, powerful trunk. According to the ideas of Lamarck, how did the trait of long, powerful trunks develop in elephants?

Gradually, as generations of elephants continued to selectively use and develop their trunks.

Nucleus

Holds genetic information

What are homologous structures? Explain why the front legs of a horse and the wings of a bat are considered homologous structures. Why are the wings of a dragonfly and the wings of a bat NOT considered homologous structures?

Homologous Structure: structures that are similar in different species of common ancestry. The front legs of a horse and the wings of a bat are not considered homologous structures because

The environment determines the fitness of an organism. Explain.

Individuals with adaptations that are well suited to their environment can survive and reproduce and are said to have high fitness. Individuals with characteristics that are not well suited to their environment either die without reproducing or leave few offspring and are said to have low fitness.

Explain each of the following and give examples: species vary locally, species vary globally, species vary over time

Species vary globally: different species living in similar environments in different locations have similarities. *ostriches- grasslands Africa, rhea- grasslands south Africa,* Species vary locally: different yet related spp of 10 occupy different habitats within the local area. *tortoises- shell varied from island to island* Species vary over time: fossils- show similarities to living spp today

Darwin observed a variety of tortoises on the Galapagos Islands. These observations provided evidence that species vary

Species vary locally. The tortoises' shells varied in different ways due to where they live on the island.

How do the gametes it produces compare with the original cell and with one another?

They are the same, both have 46. The two new daughter cells are much smaller than the original mother cell. ... 4 very different haploid daughter cells are formed. This is different than mitosis which produces only 2 diploid cells identical to the parent cells.

DeMarco researches a variety of evidence about birds and insects. He concludes that birds and insects are very distant relatives, yet they still have a common ancestor. Explain.

They both have wings, that are useful therefore they must've had some common ancestor.

Discuss the conditions necessary for natural selection to occur.

Variation for a trait, heritability, differential reproductive success.

What are vestigial structures? Give two examples.

Vestigial organs or structures are traces of homologous structures or organs in other species that no longer serve any useful function. The appendix was meant to break down very tough plant material (cellulose). Now it holds some gut bacteria that breaks down food, however, it is a liability (potential problem) because it can get infected and burst causing bacteria to enter the person's system, potentially killing them. Wisdom teeth were originally used to break down extra plant material (cellulose) and tough meat

Gene

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

Giraffes, camels, and horses share some traits, although they vary in other traits. It is believed that these animals evolved from an ancient common

ancestor

Vacuoles

plants main reserve of inorganic ions, enlarge as water comes in, allows less cytosol to be needed

Heterozygous

An organism that has two different alleles for a trait

Homozygous

An organism that has two identical alleles for a trait

Allele

Different forms of a gene

Describe the structure and functions of the cell membrane. Know which parts are hydrophobic and which parts are hydrophilic, which parts face the inside of the cell and which parts face the outside of the cell.

Forms a boundary between a cell and the surrounding environment and controls the passage of materials into and out of the cell.

Homologous

term used to refer to chromosomes that each have a corresponding chromosome from the opposite-sex parent

What is biogeography?

the study of where organisms live now and where they and their ancestors lived in the past.

Homologous structures evolve from a common_________

ancestor

haploid

(genetics) an organism or cell having only one complete set of chromosomes

Diploid

(genetics) an organism or cell having two sets of chromosomes or twice the haploid number

Why is an organism not considered fit if it cannot reproduce offspring?

A trait that increases ability to survive, but makes an individual sterile, decreases fitness because the organism cannot produce offspring to carry on the trait.

What is the end product of meiosis? Where does meiosis occur?

Cytokinesis splits the chromosome sets into new cells, forming the final products of meiosis: four haploid cells in which each chromosome has just one chromatid. In humans, the products of meiosis are sperm or egg cells.

Cell division occurs in two stages: mitosis and cytokinesis. Basically, what happens in each of these stages?

During mitosis, a eukaryotic cell undergoes a carefully coordinated nuclear division that results in the formation of two genetically identical daughter cells. ... Then, at a critical point during interphase (called the S phase), the cell duplicates its chromosomes and ensures its systems are ready for cell division. Cytokinesis is the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells. The contractile ring shrinks at the equator of the cell, pinching the plasma membrane inward, and forming what is called a cleavage furrow.

Discuss the ideas of the following scientists: Lamarck, Hutton, Malthus, Darwin, Wallace

Lamarck: In every species in nature, some individuals survive while many others die. Hutton: the inheritable traits of species may change over time. Malthus: The environment of organisms may change over time. Darwin: evidence of that living things change over time Wallace: had all the same ideas as darwin.

Discuss the importance of mitosis?

Mitosis is a way of making more cells that are genetically the same as the parent cell. It plays an important part in the development of embryos, and it is important for the growth and development of our bodies as well. Mitosis produces new cells, and replaces cells that are old, lost or damaged.

What is the end result of mitosis?

Mitosis results in two identical daughter cells, whereas meiosis results in four sex cells.

Golgi apparatus

Modifies, sorts, packages proteins for secretion or use, directs destination by adding tags (phosphate groups) and adding external molecules to vesicles to recognize docking sites.

Mitochondria

Produce ATP from glucose, powerhouse of cell, makes energy

Compare and contrast prokaryotic and eukaryotic cells.

Prokaryotic cells have a nucleoid and circular DNA. Eukaryotic cells have a nucleus, organelles, and linear DNA. They both have cells, a cell membrane, and ribosomes.

For natural and artificial selection to occur, there must be sufficient inheritable variations. Explain this.

Reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population.

Darwin collected and studied a variety of fossils. The fossils provide clues to ancient organisms. As Darwin concluded, how did ancient organisms compare to modern species?

The ancient organisms were similar to modern species, but differed in several ways.

Discuss the events that occur in meiosis and NOT mitosis? How do these events lead to different outcomes in meiosis?

The daughter cells produced by mitosis are identical, whereas the daughter cells produced by meiosis are different because crossing over has occurred. The events that occur in meiosis but not mitosis include homologous chromosomes pairing up, crossing over, and lining up along the metaphase plate in tetrads.

Endoplasmic Reticulum

make lipids (steroids, oil, phospholipids), detoxify drugs and poisons by adding OH group, stores Ca ions for muscle contraction

what is an adaption?

heritable characteristic that increases an organism's ability to survive and reproduce in an environment.

The evolution of hair in mammals occurred independently of the evolution of feathers in birds. These features are called ______ structures.

homologous

The wings of ostriches are no longer used for flying. They are considered ____ structures.

vestigial

Ribosomes

carry out proteins synthesis. Free ribosomes are in cytosol and make proteins for the cell. ER ribosomes are attached to the ER and make proteins for transport.

Nucleolus

densely stained granules and fibers where rRNA is synthesized and proteins from the cytoplasm are assembled with rRNA to form ribosome subunits.

Lyosomes

digestion in a cell, autophagy: recycle own organic material from damaged organelles in vesicles that bind to lysosomes. Food vacuoles bind to lysosomes for digestion.

Compare and contrast animal and plant cells.

same: structurally, plant and animal cells are very similar because they are both eukaryotic cells. they both contain golgi apparatus, lysosomes, and peroxisomes, cytosol, nucleuses, cytoplasm, cell membrane, mitochondria, and ribosomes. the functions of these organelles are extremely similar between the two classes of cells. different: plant cells are larger than animal cells. plant cells also have chlorophyll which have the ability to perform photosynthesis. plant cells have chloroplasts, large vacuoles, and cell walls while animal cells have cili/flagella, lysosomes, and centrioles