Homework Help for Biology (page 1087)

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Why is DNA double stranded and not single stranded?

1 Jan 2018

1. In the flour moth, Ephestia, pigment production in eyes of moths depends on a pair of nuclear alleles, A and a. The A allele directs production of a diffusible substance that his involved in pigment synthesis. This substance diffuses from a heterozygous or homozygous dominant mother into all her young, enabling them to synthesize the final pigment. All progeny of a dark-eyed female have dark eyes initially. As the moths age, only those with an AA or Aa genotype can make the diffusible substance for themselves and continue to produce pigment. Without the diffusible substrate, pigment is no longer produced and the eyes lighten with age. What eye color do you expect in young progeny, and then as they age, from each of these crosses? a) Female AA X Male AA b) Female AA X Male Aa c) Female AA X Male aa d) Female Aa X Male AA e) Female Aa X Male Aa f) Female Aa X Male aa g) Female aa X Male AA h) Female aa X Male Aa i) Female aa X Male aa

1 Jan 2018

The water-transporting cells of xylem tissue are tracheids and vessel members?

How is the structure of tracheids similar to the structure of vessel members?

How is the structure of tracheids different from the structure of vessel members?

How is the structure of both tracheids and vessel members related to their ability to serve as efficient water-conduction cells?

Sieve tube members are the conducting cells of phloem, specialized for the transport of metabolites within a plant. In what way do sieve tube members differ from a "typical" plant cell?

How do these differences improve the ability of sieve tube members to serve as efficient metabolite-conducting cells?

What is a companion cell, and what is its function?

To what tissue system does each of the following belong - tracheids, vessel members, sieve tube members, and companion cells?

The epidermis is a primary dermal tissue and the periderm is a secondary dermal tissue. Describe the most common cell types found in each of these tissues.

Both the epidermis and the periderm need to perform the same basic functions. What are those functions?

How does the structure of the epidermis contribute to those functions?

How does the structure of the periderm contribute to those functions?

What are guard cells?

How does the structure of guard cells differ from the structure of other epidermal cells?

What is the function of guard cells?

What are trichomes? What functions might trichomes perform?

What is a lenticel?

Describe its structure and function. Describe, in detail, the arrangement of primary tissues in a dicot stem. How does the arrangement of tissues in a monocot stem compare to that of dicot stems – how is it the same, how is it different?

The cortex region and the pith region of a dicot stem typically have different functions. What is the most common function of each region?

What type of tissue is each composed of?

In what types of plants does secondary growth occur?

In what plant organs does secondary growth occur?

Describe where lateral meristems form at the start of secondary growth in a stem.

Describe how the single layer of vascular cambium can produce both secondary xylem and secondary phloem.

What is wood?


early wood vs. late wood?

What allows the different layers of growth occurring each year to be visible to the human eye?

What is the function of mesophyll tissue?

What are the two types of mesophyll tissue in a typical dicot leaf?

How do these differ from each other with respect to location within the leaf, cell arrangement,

1 Jan 2018

Which of the following DNA sequences most likely represents the recognition sequence of a restriction endonuclease? [2 pt; L2; I.A.3]

c a g g a c

c t g c a g

t a g g t a

c c t c c t

1 Jan 2018

Read the article "Local and latitudinal variation in abundance: the mechanisms shaping the distribution of an ecosystem engineer" by Gregory M. Crutsinger1, Ange ́lica L. Gonzalez1, Kerri M. Crawford2 and Nathan J. Sanders3

Website https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3709108/

1.What is the hypothesis of the paper?

2.Is this a correlative or causative study? Explain

1 Jan 2018

Why and how does the proton travelling through the stalkedparticle in the inner mitochondrial membrane, cause aconformational change in the ATPase?

1 Jan 2018

16. Organisms that can undergo both photosynthesis and cellular respiration are called

decomposers c. autotrophs

heterotrophs d. omnivores

Explain please

True or False

Lipids are produced as a waste product during aerobic cellular respiration.

All autotrophs use photosynthesis to produce their food for survival.

1 Jan 2018

what is the immune response pathway of a pathogen in the gut associated lymphoid tissue?

1 Jan 2018

Which microscopy and stain procedure would you use to classify a microorganism of choice? (Microscopes: TEM, SEM, Florescence, Light…) (Stain: simple stain, gram stain, acid fast stain…) State the references for your answer.

1 Jan 2018

A 70 kg 68 y/o male sees his cardiologist for a follow-up following his myocardial infarction 3 months earlier. He has been taking digoxin and LisinoprilTM since his MI. At the follow-up, he complains of shortness of breath and has to sleep sitting up in his recliner. He also complains of fatigability and swelling of his ankles and hands. A physical examination finds that he has distended jugulars and pitting edema in the lower legs. His breathing was rapid 22 breaths/min) and rales were heard in the both sides at the base of the lungs. He does not have a fever, but his pulse is 116 bpm and his blood pressure is 110/80. The physician immediately admits him and orders a blood and urine analyses with the results as follows:




128 mEq/L


150 mEq/L


3.0 mEq/L


65 mEq/L


98 mEq/L


120 mEq/L


21 mEq/L


15 mEq/L


1.2 mg/dl


128 mg/dl


24 mmHg

24 hr volume

750 ml




600 mOsm

The physician orders an infusion of 2L of 3% saline with 40 mg of Lasix® given twice a day for three days. CALCULATE how this treatment would impact the Px’s symptoms assuming the osmolarity of the urine dropped to 400 mOsm?

1 Jan 2018

What is an autoimmune disorder? Why are these disorders often so difficult to treat?
Can you give an example of one and tell us a bit about it?

1 Jan 2018