bio study question 13, 14, bonus

Which of the following are true statements concerning the chemotherapy drug called Taxol? Check all that apply.

Taxol is thought to prevent tumor cells from dividing by preventing the formation of the spindle apparatus. Taxol has proven to be an effective treatment for ovarian and breast cancer. Taxol is thought to prevent tumor cells from dividing by immobilizing the spindle microtubules of the cells.

Which label points to the region of the chloroplast in which NADPH and ATP are used to synthesize the monosaccharide called GP3 during the light independent reactions of photosynthesis?

stroma

In order for the light dependent reactions of photosynthesis to produce ATP, large concentrations of H+ ions must build up inside what labeled compartment?

thylakoid lumen

Each of the two chains of molecules (colored blue) represenst a template strand of the original DNA molecule. Why is it referred to as the template strand?

(1/2 pt.) The template "strand" of a DNA molecule refers to the polynucleotide strand (sides of the ladder) of DNA (1/4 pt.) to which the complementary nitrogen bases attach during DNA replication.

Explain why it is essential that the cells lining the Cockroach's stomach are able to carry out mitotic cell division (mitosis + cytokinesis).

. (1/2 pt.) The cells lining the stomach are constantly being lost due to natural cell death. Cell death results from a number of factors including mechanical abrasion as the food passes through the stomach. (1/4 pt.) These cells must be replaced by the process of mitotic cell division. (1/4 pt.)

Based on the above karyotype, the 2N choromosome number of Barley is _________. pretend there is a picture with 14 chromosomes

14

The nucleus of a primary spermatocyte in the testis of a male two-toed sloth contains 48 chromosomes. The primary spermatocyte undergoes Meiosis I and II to produce four mature sperm cells. How many homologous pairs of chromosomes are found in the heart cells of the male sloth. Numerical answer only (i.e., 2, 10, etc.)

24

The nucleus of a primary spermatocyte in the testis of a male two-toed sloth contains 48 chromosomes. The primary spermatocyte undergoes Meiosis I and II to produce four mature sperm cells. The sperm cells of the male sloth would contain ______ chromosomes. why?

24 The sex cells of an organism, in this case the sperm cells of the male sloth, always contain ½ the chromosomes (N) (in this case 24)(1/4 pt.) present in the somatic cells which are 2N in chromosome #.

The nucleus of a primary spermatocyte in the testis of a male two-toed sloth contains 48 chromosomes. The primary spermatocyte undergoes Meiosis I and II to produce four mature sperm cells. Each of the 4 cells produced within the testis of the male sloth at the completion of Meiosis II would contain

24 chromosomes each composed of one chromatid

How many chromosomes will be present in the gametes of the female Perch?

3

The nucleus of a primary spermatocyte in the testis of a male two-toed sloth contains 48 chromosomes. The primary spermatocyte undergoes Meiosis I and II to produce four mature sperm cells. The heart cells of the male sloth would contain _______ chromosomes. why?

48 All of the tissues (including the heart tissue) of the somatic cells (body cells) contain the 2N chromosome #

During sexual reproduction in Barley, reproductive cells called spores are produced by meiosis within the anthers of the flowers. These spores eventually develop into pollen grains which contain the non-motile sperm. What is the N chromosome of the spores? pretend there is a picture with 14 chromosomes

7

How many homologous pairs of chromosomes are found in the leaf cells? pretend there is a picture with 14 chromosomes

7

The nucleus of each of the two stomach cells produced at the end of the M (mitotic) stage of the cell cycle will contain ____ chromosomes which is the ____ chromosome number. pretend theres a picture with 8 chromosomes

8;2N

Which two substances were produced in the light dependent reactions of photosynthesis?

A and B

What is a human karyotype and briefly explain how a human karyotype is made.

A karyotype is a picture of the 2N chromosomes (1/4 pt.) at metaphase of mitosis (1/4 pt.)

Which of the following are true statements about a sarcoma? Check all that apply.

A sarcoma is a type of malignant tumor which arises in support tissues such as bone and muscle. A sarcoma is a type of benign tumor which arises in support tissues such as bone and muscle. The cells of a sarcoma often metastasize.

What chemical compounds are produced by the light dependent reactions of photosynthesis which are used in the light independent reactions of photosynthesis? Check all that apply.

ATP NADPH

What is the function of the accessory pigments in the Light Dependent Reactions of photosynthesis?

Accessory pigments allow for the absorption of a broader spectrum of light wavelengths compared to those absorbed by chl a (1/4 pt.) which can be used for photosynthesis (1/4 pt.)

DNA is replicated.

B

What distinguishes a benign tumor from a malignant tumor?

Benign tumor = mass of "abnormal" cells which do not invade other tissues (metastasize) • Malignant tumor = mass of abnormal cells which divide uncontrollably and invade other tissues (metastasize)

Which of the following are true statements about DNA replication? Check all that apply.

DNA replication occurs in G1 phase of the cell cycle. During DNA replication, the chromosome number of cells doubles. During DNA replication, chromosomes composed of one chromatid are transformed into chromosomes composed of two chromatids.

Which one of the following is a true statement about the light dependent reactions of photosynthesis.

During the light dependent reactions, NADP+ is reduced resulting in the formation of NADPH

At which checkpoint does the cell check to determine if it has reached an optimum size for the cycle to continue.

G1

At which checkpoint does the cell check to determine if the chemical structure of the chromosomal DNA has not been damaged.

G1

At which checkpoint does the cell check to determine if the nutrient supply is adequate for the cycle to continue.

G1

Most cells double in size.

G1

Chromosomes composed of two chromatids become chromosomes composed of one chromatid.

G1 S G2

At which checkpoint does the cell check to determine if DNA replication has occured normally for the cycle to continue.

G2

Cytokinesis occurs.

G2

Double stranded chromosomes attach to the microtubules of the spindle.

G2

New cell organelles are synthesized. Check all that apply.

G2

Substance D is the monosaccharide

G3P

What are growth factors and what is there function in the control of the cell cycle?

Growth factors are • Proteins released by certain non-dividing body cells (1/4 pt.) • That stimulate other cells to divide (1/4 pt.)

Which of the following are true statements concerning spermatogenesis in human males? Check all that apply.

Human male sperm cells are produced continuously throughout the reproductive years (puberty to death) Human male sperm cells contain 22 autosomes and 1 sex chromosomes. The acrosome of a human sperm cell is an organelle containing enzymes which help sperm cells penetrate the egg cell during fertilization.

Which of the following are true statements concerning oogenesis in human females? Check all that apply.

It has been recently discovered that human ovary tissue contains stem cells which are able to produce primary oocytes throughout a female's reproductive years. Human females are born with millions of primary oocytes which are already in Prophase I of meiosis. The penetration of a sperm cell into a secondary oocyte in the oviduct triggers the secondary oocyte to complete Meiosis II.

Which of the following are true statements about chlorophyll b? Check all that apply.

It is a large organic molecule having a magnesium atom at its center. It is one of the pigments found in the light harvesting complexes of Photosystems I and II.

At which checkpoint does the cell check to determine if the chormosomes have attached properly to the spindle microtubules and the cell is ready to eneter anaphase of mitosis for the cycle to continue.

M

The length of this stage often determines the length of the entire cell cycle.

M

Enzyme F called _____________ catalyzes the addition of carbon dioxide to molecules of compound E called __________which results in the formation of 3-PGA .

Rubisco;RuBP

Chromosomes composed of one chromatid become chromosomes composed of two chromatids.

S

Describe what is occurring in each of the three steps (separated by the red arrows) of DNA replication shown in the diagram. You should refer to each of the steps as step A (furthest to the left), step B (middle diagram) and step C (furthest to the left).

Stage 1 Starting with a single stranded chromosome composed of 1 chromatid = 1 molecule DNA (1/4 pt.) Stage II 1. Hydrogen bonds between the nitrogen bases of the nucleotides of the original DNA molecule break (1/4 pt.) and each half of the original DNA molecule separates. (1/4 pt.) 2. Nucleotides in the nucleoplasm, pair with the nucleotides of the original DNA molecule (1/4 pt. Stage III Results in the production of 1 double stranded chromosome composed of 2 molecules of DNA = 2 chromatids (1/4 pt.)

What is the primary purpose (function) of electron transport during the light dependent reactions of photosynthesis?

The flow of electrons through the thylakoid membrane (electron transport) supplies the energy (1/4 pt.) required to actively transport (pump) the H ions from the stroma into the thylakoid compartment. (1/4 pt.)

Which of the following are true statements about reactive chl a molecules, P680 and P700? Check all that apply.

The numbers 680 and 700 of the reactive chl a molecules refer to the wavelenghts of light (in nanometers) which the reactive chl a molecules absorb directly. Light energy absorbed by the pigments in the light harvesting complexes of Photosystems I and II is passed to the reactive cholorphyll a molecules. They are special chl a molecules located in the reaction center of Photosystems I and II. They are the only chl a molecules in Photosystems I and II that are able to donate their high energy electrons to the primary electron acceptor molecules in the reaction centers and thus start the light dependent reactions of photosynthesis.

Which of the following are true statements concerning sex determination in humans. Check all that apply.

Up to 7 weeks of development the reproductive organs of a human embryo are neither male nor female. The SRY region of the Y chromosome is responsible for triggering the development of the testes.

List two possible ways that a proto-oncogene can be triggered to become and oncogene.

Virus infection Random mutation

During mitotic cell division, if a cockroach intestinal cell undergoes mitosis but not cytokinesis, what will result?

a chromosome composed of two chromatids a chomosome composed of one chromatid one molecule of DNA

The chromatids of double stranded chromosomes are pulled apart.

anaphase

Which label represents the enzyme which is directly responsible for the production of ATP during the light dependent reactions of chlorophyll?

bottom purple gray thing

The oxygen produced during the Light Dependent Reactions of photosynthesis may ______. Check all that apply.

diffuse out of the choloroplast and eventually out of the plant tissue and into the atmosphere. be consumed by the plant during aerobic respiration

In this example, the fully mature sex cells produced by the female perch at the end of Meiosis II are called

eggs

Which process is responsible for the movement of molecules 1 from the thylakoid compartment across the thylakoid membrane via molecule 5?

facilitated diffusion

Which label points to the membrane containing the photosynthetic pigments which trap the light energy?

granum

chlorophyll a carotenoid chlorophyll b

green little dots inside the purple represent what

Chromosomes composed of two chromatids (double stranded chromosomes) line up at the equator of the cell.

metaphase

The gray compound enclosed by the circle represents a monomer of DNA called a (an) _____________

nucleotide

Within which organelle in a eukaryotic cell does DNA replication occur?

nucleus

Chromatin fibers become tightly coiled to form discrete chromosomes.

prophase

The nuclear envelope disappears.

prophase

Enzymes in the chloroplast and cytoplasm of the plant cell can convert the G3P synthesized during the Light Independent Reactions into _____. Check all that apply.

starch amino acids fatty acids nucleic acids sucrose glucose cellulose

A complete set of chromosomes composed of one chromatid (single stranded chromosomes) is found at each pole of the dividing cell.

telophase

Cytokinesis is completed at the end

telophase

thylakoid

what are the individual disks called

H+

what are the light blue little circles called

Four single stranded chromosomes composed of one chromatid One double stranded chromosome composed of two chromatids.

what does this whole thing represent

inner membrane of chloroplasts

what is label B

thymine

what is the T

reactive chlorophyll a p700

what is the green circle inside the middle of the right(or second) grayish purple thing

thylakoid lumen

what is the space 5 is Pointing to

In the Bios 101 lab you measure the rate of oxygen evolution by a sage plant using an oxygen electrode. Explain why are you only measuring the net oxygen produced rather than the total (gross) oxygen produced?

• A plant in the light produces oxygen via photosynthesis (1/4 pt.) but some of that oxygen gas (i.e. the oxygen produced by photosynthesis) is being consumed by aerobic respiration (1/4 pt.) of the plant tissue. • Gross oxygen production minus the oxygen being consumed = net oxygen produced.

Briefly explain how the process of cytokinesis in the stomach cell of a Cockroach would differ from cytokinesis in an actively dividing root cell of a Barley plant.

• Cytokinesis in a dividing plant cell occurs by the growth of a cell plate (membranous sac containing pectin) (1/4 pt.) that grows outward from the cell center (1/4 pt.) and fuses with the cell membrane of the parent cell. • Cytokinesis in a dividing animal cell (e.g. cockroach stomach cell) occurs by pinching in of the cell membrane (½ pt.) caused by contracting belt of microfilaments.

A biologist working for Monsanto, develops an herbicide which kills weeds by blocking the flow of electrons between photosystems II and photosystems I during the Light Dependent Reactions of photosynthesis. Based on your knowledge of the Light Dependent Reactions, explain why the weeds are killed after treatment with the herbicide.

Since the herbicide blocks the flow of electrons through the thylakoid membrane, no electrical energy is produced (1/4 pt.) which is necessary for the active transport of H+ from the stroma into the thylakoid compartment (1/4 pt.) • As a result there is a very low H+ concentration in the thylakoid compartment (1/4 pt.) Resulting in very low or no ATP being produced by the flow of H+ through ATP synthase. (1/4 pt.) • Since ATP is required for the synthesis of the sugar GP3 in the light independent reactions. The plant is no longer able to produce all of its organic compounds and the plant dies. (1/4 pt.)

Genetic recombination occurs during gamete formation and results in an increase the genetic variability (genotypes) of the gametes. (1) What are the two major processes that occur during meiosis which are responsible for this genetic recombination and (2) List the stage in meiosis I or II in which each process occurs.

1. Crossing-over- occurs in Prophase I 2. Independent Assortment of Chromosomes- occurs in Metaphase II (1/4 pt.)

The nucleus of a primary spermatocyte in the testis of a male two-toed sloth contains 48 chromosomes. The primary spermatocyte undergoes Meiosis I and II to produce four mature sperm cells. Each of the 2 cells within the testis of the male sloth at the end of Meiosis I would contain

24 chromosomes each composed of two chromatids

Explain why there is a 50% chance at each birth that the baby will be male or female.

Human sperm cells contain either one X chromosome or one Y chromosome (1/4 pt.) Therefore, at each fertilization there is a 50% chance that the zygote will contain an X from the female egg and an X from the male or an X from the female and a Y from the male

why is the build up of greenhouse gases in the atmosphere result in global warming.

Infrared radiation is low energy; long wavelength electromagnetic radiation emitted from objects as heat (1/4 pt.) • Greenhouse gases absorb infrared radiation and re-radiate it as heat (1/4) • Greenhouse gases slow down the escape of infrared radiation from earth (1/4 pt.) resulting in increased temperatures on earth (1/4 pt.)

Which of the following are true statements concerning chlorophyll a? Check all that apply.

It absorbs primarily blue, violet, and red light. It is a large organic molecule having a magnesium atom at its center. It is a primary pigment. It reflects primarily green light. It occurs as one of the pigments in the light harvesting complexes of Photosystems I and II.

Which of the following are true statements about the process of crossing over? Check all that apply.

It is a type of genetic recombination It results in increasing the genetic diversity of the gametes resulting from meiosis.

NADP+

know this

What greenhouse gas is produced in large quantities as a result of anerobic respiration of certain species of Archeae living in the gut of herbivorous (ruminants) and omnivorous vertebrates?

methane

The spindle apparatus is formed.

prophase

Which labeled structures within the chloroplast may be responsible for the synthesis of some of the enzymes required by the biochemical reactions of photosynthesis?

ribosomes

During the Light Dependent Reactions, which substance is the source of the electrons which replace those lost by chorophyll a P680 in Photosystme II?

water

photosystem II

what is the whole thing in the white box

Telophase I of meiosis

what stage

When a plant is in the light, name two sources of the carbon dioxide gas being used by the plant cells during photosynthesis.

• Carbon dioxide taken in from the environment (1/4 pt.) • Carbon dioxide results from aerobic respiration of the plant (1/4 pt.)

Explain why the synthesis of G3P is necessary for the continued functioning of the Light Independent Reactions of Photosynthesis.

• At the start of the Calvin cycle, carbon dioxide combines with RuBP via an enzyme (Rubisco) mediated reaction to form phosphoglycerate which is then converted through a series of enzyme catalyzed reactions to form the three carbon monosaccharide called G3P. (1/4 pt.) • Small amount of the G3P are used by the plant to synthesize all of its organic nutrients. • Using energy from ATP and NADPH, large amounts of the G3P is recycled through a series of biochemical reactions to form more RuBP which is required to start the Calvin cycle again. (1/4 pt.)

What are the two sources of H+ ions which build up in the thylakoid compartment during the light dependent reactions of photosynthesis?

• The H+ which are pumped from the stroma into the thylakoid compartment by active transport. ( 3 pt.) • The H+ resulting from the breakdown of water in the thylakoid compartment (1/4 pt.)