the energy necessary to power the rearrangement of chemical bonds
Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by_______
Lungs are to breathing as _____ are to cellular respiration.
kinetic energy and heat
When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to _____.
Given the relatively modest number of calories burned by anything but the most vigorous activities, why can people consume over 2,000 kilocalories a day, yet maintain a healthy body weight?
Most of the energy consumed in food is spent maintaining the body's functions, so only a fraction of food energy needs to be burned in exercise
loses electrons and loses energy
A molecule that functions as the electron donor in a redox reaction _____.
loses ... oxygen gains
In cellular respiration, glucose _____ electrons, whereas _____
these two stages supply the electrons needed for the electron transport chain
Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____.
requires ATP to make ATP
Glycolysis is the only stage of cellular respiration that _____
In the reaction that creates acetyl CoA (coenzyme A) from pyruvate
We inhale O2 and we exhale CO2. Carbon dioxide is produced _____.
A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes?
What molecule is required to move pyruvate to the citric acid cycle?
pump protons (H+) across the mitochondrial membrane
In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to _____.
Dinitrophenol (DNP) is a highly toxic membrane uncoupler. What happens when DNP makes the phospholipid bilayer of inner mitochondrial membranes permeable to protons (H+)?
Many protons would bypass ATP synthase, leading to a sharp decline in ATP synthesis.
oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain
Some human cells are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then _____.
Humans depend on oxygen to sustain life. However, at the cellular level, muscle cells are _____.
with their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons
Fat is the most efficient molecule for long-term energy storage even compared to carbohydrates because _____.
power the biosynthesis of amino acids, fats, and sugars
Using the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle can be siphoned off and used to _____.
can produce great variation among the offspring
Asexual and sexual reproduction differ in that sexual reproduction _____
Consider the process by which bacterial populations grow. What process performs a similar function in humans?
It ensures the separation of the replicated chromosomes as new membrane is made
During binary fission, the replicated bacterial chromosome attaches to the plasma membrane by specialized anchor proteins. What is the purpose of this attachment between chromosome and membrane?
The sequences are identical
Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?
NA is synthesized in the S phase of interphase.
Which of the following statements correctly describes the timing of DNA synthesis?
The mitotic spindle would not form
What would be the immediate consequence of destroying a cell's centrosomes?
they attach to a dynamic, precisely regulated mitotic spindle
During mitosis, the chromosomes move because _____
cytokinesis in a plant cell
A cell is treated with a drug that prevents the formation of intracellular (within the cell) vesicles. Which of the following processes would be blocked?
Cancer cells continuously secrete growth factors into the cell culture medium.
In the laboratory, cancer cells fail to show density-dependent inhibition of growth in cell culture. What is one explanation that could account for this?
When examining cells in the laboratory, you notice that a particular cell has half as much DNA as the surrounding cells. It appears that this cell's cell cycle halted at checkpoint _____.
cells of a benign tumor remain within the tumor, whereas cells of a malignant tumor can spread to other body tissues
A benign and a malignant tumor differ in that _____.
divide by mitosis
When forming buds, hydras _____.
are identical in the arrangement of their genes, but some versions of the genes may differ between the chromosomes
In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____
Baker's yeast is an organism with 32 chromosomes that can perform asexual or sexual reproduction and exist as both a diploid and haploid cell. After meiosis, how many chromosomes will be present in each cell?
haploid and the sister chromatids are joined
At the conclusion of meiosis I, the daughter cells are _____.
sister chromatids are separated
In meiosis II, _____.
The pairing up of homologous chromosomes and crossing over only occur during meiosis.
The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How?
If we assume that crossing over does not occur, how many different combinations of chromosomes are possible in a zygote derived from diploid parents who each have three pairs of chromosomes?
Inbreeding has a number of interesting effects. For one, highly in-bred strains (varieties) may carry identical forms of every gene. Mice have 40 chromosomes in their diploid (2n) set. How many genetically distinct kinds of gametes (gametes with different genetic characteristics) could be produced through meiosis in an in-bred strain where there are identical forms of every gene?
This brings the chromosomes into alignment so that crossing over can create new combinations of genes present on a single chromosome
During meiosis I, homologous chromosomes form a tetrad. What does this accomplish?
In a cell with eight chromosomes, one chiasma develops during meiosis I in only one particular pair of homologs. How many recombinant chromosomes will there be at the completion of meiosis II?
During mitosis, chromosomes are more condensed than during interphase
Scientists commonly choose white blood cells that are going through mitosis to prepare karyotypes. Why?
Trisomy for the other autosomal chromosomes is often lethal, and the affected embryos are miscarried.
Although in humans there are 22 pairs of autosomal chromosomes, only three different chromosomal trisomies are commonly seen in newborns. Of the remaining 19 autosomes, many trisomies have not been seen in newborns. Why not?
Two of the embryos will be trisomic for chromosome 18, and two will contain a single copy of chromosome 18.
In theory, when a nondisjunction for chromosome 18 occurs during meiosis I, four gametes can be produced. If these gametes are fertilized with unaffected gametes from the second parent, what observations would you make concerning the resulting embryos?
Only one copy of the X chromosome is active, regardless of the total number of X chromosomes.
Trisomy for most autosomes is fatal, yet trisomy or even tetrasomy (four copies) of the X chromosome is not. What is the explanation for this difference?
There are species of coffee plant with 22, 44, 66, and 88 chromosomes. All but one of these species is considered to be an example of polyploidy. Plant geneticists believe that the original haploid number of chromosomes in coffee was _____.
In trisomy there would be one extra chromosome; in a duplication, one chromosome would have two copies of a portion of the chromosome
You suspect that a serious developmental disorder is due to a chromosome abnormality and prepare a karyotype from an affected individual. In analyzing the karyotype, how could you distinguish trisomy from a chromosome structural defect such as a duplication?